SFtp Lua Reference Documentation

chilkat.SFtp

Current Version: 11.7.0

Markdown version of this page for AI tools (v 11.7.0) · all AI docs

Chilkat.SFtp

Transfer, list, manage, and synchronize files over SFTP.

Chilkat.SFtp is Chilkat's main class for secure file transfer over SSH. It provides SSH connection and authentication, SFTP subsystem initialization, uploads, downloads, directory listings, remote file management, file attributes, handle-based file access, recursive synchronization, bandwidth throttling, proxy support, host key fingerprinting, SSH algorithm controls, and detailed diagnostics.

SSH + SFTP setup

Connect to an SSH server, authenticate with password or key-based credentials, then initialize the SFTP subsystem before file operations.

Upload and download

Transfer files using simple path-based APIs, in-memory data, streams, or handle-based methods when lower-level control is needed.

Directory and file management

List directories, create and remove folders, rename files, delete files, inspect attributes, and work with remote paths.

Sync-tree operations

Upload or download directory trees and synchronize local and remote folder structures.

Security controls

Verify host keys, control accepted SSH algorithms, use private keys, and configure proxy or network settings when required.

Diagnostics and reliability

Use detailed error text, session logs, progress callbacks, bandwidth limits, and timeout settings to troubleshoot real-world server behavior.

Common pattern: Connect, authenticate, initialize SFTP, perform file operations using remote paths or handles, close any open handles, and disconnect. Use handle-based APIs for precise control, and synchronization methods for recursive folder transfers.

Object Creation

local chilkat = require("chilkat")

local sftp = chilkat.SFtp.new()
local sftp = chilkat.SFtp.new()

Creates the object (chilkat.SFtp() does the same). Lua's garbage collector frees it when it is no longer referenced; sftp:dispose() frees it at once, and in Lua 5.4 and later local sftp <close> = chilkat.SFtp.new() frees it when the block ends. Calling a method of a disposed object raises an error.

Errors

A method that fails returns nil followed by the error text, as io.open does: local body, err = sftp:method(...), where err is the object's last_error_text. Wrap the call in assert() to raise an error with that text instead. Methods that answer a question return true or false, numbers are returned as they are (check last_method_success where the description says a value means failure), and property reads and writes never fail for Chilkat reasons.

Misuse raises a Lua error: a wrong argument type or a missing argument (bad argument #1 to ...), an unknown property name, a write to a read-only property, an out-of-range integer, or an object of the wrong class.

Names are Chilkat's in snake_case: QuickGetStr is quick_get_str, LastErrorText is last_error_text. Properties are fields (sftp.verbose_logging = true) and methods use the colon (sftp:method(...)). Strings are UTF-8; binary data is a Lua string of bytes. Indexes are 0-based, as in every Chilkat API. Unlocking: call chilkat.unlock_bundle("...") once at startup.

Properties

AbortCurrent
-- boolVal is a boolean
local boolVal = sftp.abort_current
sftp.abort_current = boolVal
Introduced in version 9.5.0.58

Set to true to request that the currently running Chilkat operation abort. Both synchronous and asynchronous operations can be canceled; a synchronous call may be interrupted by setting this property from another thread.

When the abort is observed, the current method returns failure and Chilkat resets this property to false. If no method is running, it is reset when the next method begins.

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AuthFailReason
-- intVal is an integer (read-only)
local intVal = sftp.auth_fail_reason
Introduced in version 9.5.0.52

Contains the result code from the most recent call to AuthenticatePw, AuthenticatePk, AuthenticatePwPk, or a corresponding secure-string authentication method.

ValueMeaning
1Transport failure: communication was lost, or a network read or write failed or timed out.
2Invalid private key: the key format, key type, or key contents are not suitable for public-key authentication.
3No mutually supported authentication method is available.
4SSH authentication protocol error: an unexpected or invalid message was received.
5The server rejected the supplied password or private key.
6The SSH session is already authenticated.
7The server requires a password change. See PasswordChangeRequested.
Read this property immediately after an authentication method fails. Also inspect LastErrorText for detailed diagnostics.
Lifetime: A later successful authentication does not necessarily reset this value. Consult it only immediately after an authentication method returns false; do not use an older value to describe the current session.

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BandwidthThrottleDown
-- intVal is an integer
local intVal = sftp.bandwidth_throttle_down
sftp.bandwidth_throttle_down = intVal
Introduced in version 9.5.0.49

Specifies the approximate maximum download rate, in bytes per second. The default is 0, which disables download throttling.

Bandwidth throttling is approximate. Actual throughput can vary because of network latency, SSH framing, buffering, and server behavior.

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BandwidthThrottleUp
-- intVal is an integer
local intVal = sftp.bandwidth_throttle_up
sftp.bandwidth_throttle_up = intVal
Introduced in version 9.5.0.49

Specifies the approximate maximum upload rate, in bytes per second. The default is 0, which disables upload throttling.

Bandwidth throttling is approximate. Actual throughput can vary because of network latency, SSH framing, buffering, and server behavior.

More Information and Examples
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ClientIdentifier
-- strVal is a string
local strVal = sftp.client_identifier
sftp.client_identifier = strVal

Specifies the SSH client-identification string sent when a connection is established. The default begins with SSH-2.0-Chilkat_ followed by the Chilkat version, for example SSH-2.0-Chilkat_11.6.0.

The value should begin with SSH-2.0-. A server may disconnect if the identification string is invalid.

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ClientIpAddress
-- strVal is a string
local strVal = sftp.client_ip_address
sftp.client_ip_address = strVal

This property is normally left unset. Set it only on a multihomed computer when the application must bind the outgoing connection to a specific local network interface.

Specify a numeric IPv4 or IPv6 address, not a hostname. When the property is empty, the operating system automatically chooses the local address.

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ConnectTimeoutMs
-- intVal is an integer
local intVal = sftp.connect_timeout_ms
sftp.connect_timeout_ms = intVal

Specifies the maximum number of milliseconds allowed for the remote endpoint to accept the TCP connection.

This setting covers TCP connection establishment. After the socket is connected, receive and transfer inactivity are governed by IdleTimeoutMs and method-specific timeouts.

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DebugLogFilePath
-- strVal is a string
local strVal = sftp.debug_log_file_path
sftp.debug_log_file_path = strVal

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

More Information and Examples
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DisconnectCode
-- intVal is an integer (read-only)
local intVal = sftp.disconnect_code

Contains the RFC 4253 reason code from the most recent SSH DISCONNECT message received from the server. A value of 0 means no server-provided disconnect code is available.

CodeSymbolic name
1SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT
2SSH_DISCONNECT_PROTOCOL_ERROR
3SSH_DISCONNECT_KEY_EXCHANGE_FAILED
4SSH_DISCONNECT_RESERVED
5SSH_DISCONNECT_MAC_ERROR
6SSH_DISCONNECT_COMPRESSION_ERROR
7SSH_DISCONNECT_SERVICE_NOT_AVAILABLE
8SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED
9SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE
10SSH_DISCONNECT_CONNECTION_LOST
11SSH_DISCONNECT_BY_APPLICATION
12SSH_DISCONNECT_TOO_MANY_CONNECTIONS
13SSH_DISCONNECT_AUTH_CANCELLED_BY_USER
14SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE
15SSH_DISCONNECT_ILLEGAL_USER_NAME

See DisconnectReason for the server-provided descriptive text.

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DisconnectReason
-- strVal is a string (read-only)
local strVal = sftp.disconnect_reason

Contains the descriptive text sent with the most recent server SSH DISCONNECT message. See DisconnectCode for the corresponding RFC 4253 reason code.

The text is supplied by the server and can be empty or generic. An ordinary TCP loss or a local disconnect does not necessarily produce an SSH disconnect reason.

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EnableCache
-- boolVal is a boolean
local boolVal = sftp.enable_cache
sftp.enable_cache = boolVal

Controls whether Chilkat caches remote file sizes and attributes requested by GetFileSize32, GetFileSize64, GetFileSizeStr, GetFileCreateTimeStr, GetFileLastAccessStr, GetFileLastModifiedStr, GetFileOwner, GetFileGroup, GetFilePermissions. The default is false.

When enabled, requesting one attribute by filename causes the complete attribute set for that file to be cached. Later attribute requests for the same filename can be satisfied without another server round trip.

Caching applies only when a remote path is used, not when an open handle is used. Call ClearCache when remote metadata may have changed.

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EnableCompression
-- boolVal is a boolean
local boolVal = sftp.enable_compression
sftp.enable_compression = boolVal
Introduced in version 9.5.0.56

Controls whether SSH compression may be negotiated. The default is false.

Some older servers advertise compression but fail when it is enabled. If the server disconnects during or immediately after connection or authentication, try leaving this property false.

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EnableSecrets
-- boolVal is a boolean
local boolVal = sftp.enable_secrets
sftp.enable_secrets = boolVal
Introduced in version 11.5.0

Enables automatic resolution of secret specification strings from secure operating-system storage. The default is false.

When true, supported password properties and authentication methods may receive a value beginning with !! instead of a literal credential. Chilkat resolves the secret from Windows Credential Manager on Windows or Apple Keychain on macOS.

Secret specification format:

!![appName|]service[|domain]|username

This feature applies to HttpProxyPassword, SocksPassword, AuthenticatePw, and AuthenticatePwPk.

More Information and Examples
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FilenameCharset
-- strVal is a string
local strVal = sftp.filename_charset
sftp.filename_charset = strVal

Specifies the character encoding used for SFTP filenames. During InitializeSftp, Chilkat automatically sets this property when the server supplies a filename-charset extension.

When the property is empty, incoming and outgoing filenames use UTF-8. Otherwise, Chilkat uses the specified charset, such as utf-8, iso-8859-1, or windows-1252.

Use an explicit charset only when required by the server. UTF-8 is the normal SFTP filename encoding.

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ForceCipher
-- strVal is a string
local strVal = sftp.force_cipher
sftp.force_cipher = strVal

Restricts SSH cipher negotiation to a single cipher. Leave this property empty to use Chilkat's normal preference order. For broader algorithm control, use SetAllowedAlgorithms.

Cipher nameFamily
chacha20-poly1305@openssh.comChaCha20-Poly1305 authenticated encryption
aes128-ctr, aes192-ctr, aes256-ctrAES in CTR mode
aes128-cbc, aes192-cbc, aes256-cbcAES in CBC mode
aes128-gcm@openssh.com, aes256-gcm@openssh.comAES-GCM authenticated encryption
twofish128-cbc, twofish256-cbcTwofish in CBC mode
blowfish-cbcBlowfish in CBC mode
If the server does not support the selected cipher, Connect fails.

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ForceV3
-- boolVal is a boolean
local boolVal = sftp.force_v3
sftp.force_v3 = boolVal

Controls SFTP protocol-version negotiation. The default is true, which forces use of SFTP v3 even when the server supports a newer version.

Set this property to false before InitializeSftp when the application needs features introduced in SFTP v4, v5, or v6. After initialization, read ProtocolVersion to determine the negotiated version.

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HeartbeatMs
-- intVal is an integer
local intVal = sftp.heartbeat_ms
sftp.heartbeat_ms = intVal

Specifies the interval, in milliseconds, between AbortCheck event callbacks during operations that support progress events. The default is 0, which disables periodic callbacks.

More Information and Examples
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HostKeyAlg
-- strVal is a string
local strVal = sftp.host_key_alg
sftp.host_key_alg = strVal

Specifies the preferred host-key algorithm used during SSH connection establishment. The default is DSS; set it to RSA only when required for compatibility with a particular server.

Normally this property should be left unchanged.

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HostKeyFingerprint
-- strVal is a string (read-only)
local strVal = sftp.host_key_fingerprint

Contains the connected server's host-key fingerprint in Chilkat's legacy MD5 format. The value is set after a successful SSH connection.

ssh-rsa 2048 68:ff:d1:4e:6c:ff:d7:b0:d6:58:73:85:07:bc:2e:d5
ssh-ed25519 256 c8:73:22:c7:82:aa:09:f1:1c:4e:99:8a:a0:62:a7:87
For new applications, use GetHostKeyFP with SHA256. Compare the fingerprint with a value obtained from a trusted source before sending credentials.
The value is cleared by Disconnect. Obtain and validate it while the SSH connection is active.

More Information and Examples
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HttpProxyAuthMethod
-- strVal is a string
local strVal = sftp.http_proxy_auth_method
sftp.http_proxy_auth_method = strVal

Specifies the authentication method used by an HTTP proxy. Matching is case-insensitive.

ValueBehavior
emptyAutomatically negotiate a supported method.
BasicUse HTTP Basic authentication.
NTLMUse NTLM authentication.

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HttpProxyDomain
-- strVal is a string
local strVal = sftp.http_proxy_domain
sftp.http_proxy_domain = strVal

Specifies the optional Windows domain used for NTLM authentication with an HTTP proxy. This property is ignored for Basic authentication.

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HttpProxyHostname
-- strVal is a string
local strVal = sftp.http_proxy_hostname
sftp.http_proxy_hostname = strVal

Specifies the hostname or numeric IP address of an HTTP proxy used to establish the SSH connection.

Set this property together with HttpProxyPort. A configured SOCKS proxy takes precedence when SocksVersion is 4 or 5.

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HttpProxyPassword
-- strVal is a string
local strVal = sftp.http_proxy_password
sftp.http_proxy_password = strVal

Specifies the password used to authenticate with an HTTP proxy.

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HttpProxyPort
-- intVal is an integer
local intVal = sftp.http_proxy_port
sftp.http_proxy_port = intVal

Specifies the HTTP proxy port. Common values include 8080 and 3128.

The proxy is used when HttpProxyHostname is nonempty, this property is nonzero, and SocksVersion is 0.

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HttpProxyUsername
-- strVal is a string
local strVal = sftp.http_proxy_username
sftp.http_proxy_username = strVal

Specifies the username used to authenticate with an HTTP proxy.

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IdleTimeoutMs
-- intVal is an integer
local intVal = sftp.idle_timeout_ms
sftp.idle_timeout_ms = intVal

Specifies the maximum period, in milliseconds, during which an SFTP operation may make no progress while sending or receiving data. The default is 30000 (30 seconds).

Set this property to 0 to allow an operation to wait indefinitely.

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IncludeDotDirs
-- boolVal is a boolean
local boolVal = sftp.include_dot_dirs
sftp.include_dot_dirs = boolVal

Controls whether ReadDir and ReadDirListing include the special . and .. directory entries. The default is false.

This property controls only the special directory entries . and ... It does not exclude ordinary hidden filenames such as .gitignore or .profile.

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InitializeFailCode
-- intVal is an integer (read-only)
local intVal = sftp.initialize_fail_code

Contains the RFC 4254 channel-open failure code when InitializeSftp cannot open the SFTP session channel. The initial value is 0.

CodeSymbolic name
1SSH_OPEN_ADMINISTRATIVELY_PROHIBITED
2SSH_OPEN_CONNECT_FAILED
3SSH_OPEN_UNKNOWN_CHANNEL_TYPE
4SSH_OPEN_RESOURCE_SHORTAGE

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InitializeFailReason
-- strVal is a string (read-only)
local strVal = sftp.initialize_fail_reason

Contains the descriptive text associated with InitializeFailCode when InitializeSftp cannot open the SFTP session channel. The text is supplied by the server and may be empty or generic.

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IsConnected
-- boolVal is a boolean (read-only)
local boolVal = sftp.is_connected

Returns true when Chilkat's last known state indicates that the underlying SSH transport is connected. This means Connect succeeded; it does not mean authentication or InitializeSftp has completed.

This property is passive and does not perform network I/O. A silent network failure or a peer close may remain undetected until an operation reads from or writes to the socket.

To actively test whether the connection is still writable, call SendIgnore and check its return value. The server does not reply to an SSH IGNORE message.

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KeepSessionLog
-- boolVal is a boolean
local boolVal = sftp.keep_session_log
sftp.keep_session_log = boolVal

Controls whether SSH and SFTP protocol traffic is accumulated in SessionLog. The default is false.

Session logging is intended for diagnostics and grows as activity continues. Disable it when no longer needed and treat the resulting log as potentially sensitive.

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LastErrorHtml
-- strVal is a string (read-only)
local strVal = sftp.last_error_html

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
-- strVal is a string (read-only)
local strVal = sftp.last_error_text

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
-- strVal is a string (read-only)
local strVal = sftp.last_error_xml

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
-- boolVal is a boolean
local boolVal = sftp.last_method_success
sftp.last_method_success = boolVal

Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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LastStatusCode
-- intVal is an integer (read-only)
local intVal = sftp.last_status_code
Introduced in version 9.5.0.85

Contains the numeric code from the most recently received SFTP SSH_FXP_STATUS response. This is not necessarily the status of the most recently called method. Methods that return a handle, attributes, or data can complete without receiving a new status response, leaving an older value unchanged. A successful method can therefore leave a previous nonzero status code in this property.

CodeSymbolic name
0SSH_FX_OK
1SSH_FX_EOF
2SSH_FX_NO_SUCH_FILE
3SSH_FX_PERMISSION_DENIED
4SSH_FX_FAILURE
5SSH_FX_BAD_MESSAGE
6SSH_FX_NO_CONNECTION
7SSH_FX_CONNECTION_LOST
8SSH_FX_OP_UNSUPPORTED
9SSH_FX_INVALID_HANDLE
10SSH_FX_NO_SUCH_PATH
11SSH_FX_FILE_ALREADY_EXISTS
12SSH_FX_WRITE_PROTECT
13SSH_FX_NO_MEDIA
14SSH_FX_NO_SPACE_ON_FILESYSTEM
15SSH_FX_QUOTA_EXCEEDED
16SSH_FX_UNKNOWN_PRINCIPAL
17SSH_FX_LOCK_CONFLICT
18SSH_FX_DIR_NOT_EMPTY
19SSH_FX_NOT_A_DIRECTORY
20SSH_FX_INVALID_FILENAME
21SSH_FX_LINK_LOOP
22SSH_FX_CANNOT_DELETE
23SSH_FX_INVALID_PARAMETER
24SSH_FX_FILE_IS_A_DIRECTORY
25SSH_FX_BYTE_RANGE_LOCK_CONFLICT
26SSH_FX_BYTE_RANGE_LOCK_REFUSED
27SSH_FX_DELETE_PENDING
28SSH_FX_FILE_CORRUPT
29SSH_FX_OWNER_INVALID
30SSH_FX_GROUP_INVALID
31SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK

See LastStatusMessage for the server-provided message text.

Use each method's documented return value as the primary success test. Read this property immediately after a relevant SFTP failure when the server status provides additional detail.

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LastStatusMessage
-- strVal is a string (read-only)
local strVal = sftp.last_status_message
Introduced in version 9.5.0.85

Contains the message text from the most recently received SFTP SSH_FXP_STATUS response. The wording is server-dependent.

This property can remain unchanged across later successful methods that do not receive a new status response. See LastStatusCode for the numeric code.

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MaxPacketSize
-- intVal is an integer
local intVal = sftp.max_packet_size
sftp.max_packet_size = intVal

Specifies the maximum packet length used by the underlying SSH transport. The default is 32768 bytes.

Normally this property should remain unchanged.

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PasswordChangeRequested
-- boolVal is a boolean (read-only)
local boolVal = sftp.password_change_requested

Indicates that the server rejected password authentication because the account password must be changed. This property is set by AuthenticatePw and AuthenticatePwPk.

When true, call the authentication method again and pass the old and new passwords in this form:

|oldPassword|newPassword|

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PercentDoneScale
-- intVal is an integer
local intVal = sftp.percent_done_scale
sftp.percent_done_scale = intVal
Introduced in version 9.5.0.49

Specifies the value representing 100% completion in PercentDone event callbacks. The default is 100.

For example, a scale of 1000 provides 0.1% granularity, so a callback value of 453 represents 45.3% complete. Values are clamped to the range 10 through 100000.

This property applies only in environments that support event callbacks and only to operations for which progress can be measured.

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PreferIpv6
-- boolVal is a boolean
local boolVal = sftp.prefer_ipv6
sftp.prefer_ipv6 = boolVal

Controls the preferred address family when DNS resolution returns both IPv4 and IPv6 addresses. The default is false, which prefers IPv4. Set it to true to prefer IPv6.

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PreserveDate
-- boolVal is a boolean
local boolVal = sftp.preserve_date
sftp.preserve_date = boolVal

Controls whether path-based upload and download methods preserve source timestamps on the destination. The default is false.

Last-modified time is preserved when supported by the negotiated SFTP version and destination filesystem. SFTP v3 represents these times with whole-second precision and does not provide a creation-time attribute; creation-time preservation requires a later protocol version and server support.

This property does not apply to low-level transfers performed by opening a remote handle, reading or writing the data, and then closing the handle.

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ProtocolVersion
-- intVal is an integer (read-only)
local intVal = sftp.protocol_version

Contains the SFTP protocol version negotiated by InitializeSftp, normally a value from 3 through 6.

Chilkat and the server exchange their highest supported versions, and the session uses the lower compatible version. Features unavailable in older versions are identified throughout this reference documentation.

The initial value is 0. After a successful initialization, the negotiated value can remain populated after Disconnect and during a later connection before SFTP is initialized again. Do not use this property alone to determine whether an SFTP channel is currently open.

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ReadDirMustMatch
-- strVal is a string
local strVal = sftp.read_dir_must_match
sftp.read_dir_must_match = strVal
Introduced in version 9.5.0.53

Specifies a semicolon-separated list of filename patterns. When nonempty, ReadDir and ReadDirListing include only entries matching at least one pattern.

  • * matches zero or more characters.
  • Matching is case-insensitive.
  • ? and bracket expressions such as [0-9] are not wildcard operators.
  • Surrounding whitespace and empty entries between semicolons are ignored.
*.xml; *.txt; *.csv

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ReadDirMustNotMatch
-- strVal is a string
local strVal = sftp.read_dir_must_not_match
sftp.read_dir_must_not_match = strVal
Introduced in version 9.5.0.53

Specifies a semicolon-separated list of filename patterns. When nonempty, ReadDir and ReadDirListing exclude entries matching any pattern. Exclusion is applied after ReadDirMustMatch.

  • * matches zero or more characters.
  • Matching is case-insensitive.
  • ? and bracket expressions such as [0-9] are not wildcard operators.
  • Surrounding whitespace and empty entries between semicolons are ignored.
*.tmp; *.bak; *.log

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ServerIdentifier
-- strVal is a string (read-only)
local strVal = sftp.server_identifier
Introduced in version 9.5.0.71

Contains the SSH server-identification string received during connection establishment. For example:

SSH-2.0-OpenSSH_8.9p1 Ubuntu-3ubuntu0.16
The last received identifier can remain populated after Disconnect. Use IsConnected to determine whether the SSH transport is currently connected.

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SessionLog
-- strVal is a string (read-only)
local strVal = sftp.session_log

Contains the in-memory SSH/SFTP protocol log. Enable logging by setting KeepSessionLog to true.

This property contains log text, not a file path. Call ClearSessionLog to clear it.

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SocksHostname
-- strVal is a string
local strVal = sftp.socks_hostname
sftp.socks_hostname = strVal

Specifies the SOCKS proxy hostname or IPv4 address. This property is used only when SocksVersion is 4 or 5.

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SocksPassword
-- strVal is a string
local strVal = sftp.socks_password
sftp.socks_password = strVal

Specifies the SOCKS5 password when username/password authentication is required. SOCKS4 does not use a password, so this property is ignored when SocksVersion is 4.

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SocksPort
-- intVal is an integer
local intVal = sftp.socks_port
sftp.socks_port = intVal

Specifies the SOCKS proxy port. The default is 1080. This property is used only when SocksVersion is 4 or 5.

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SocksUsername
-- strVal is a string
local strVal = sftp.socks_username
sftp.socks_username = strVal

Specifies the SOCKS proxy username. For SOCKS4 it is sent as the user ID; for SOCKS5 it is used with SocksPassword for username/password authentication.

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SocksVersion
-- intVal is an integer
local intVal = sftp.socks_version
sftp.socks_version = intVal

Selects whether and how a SOCKS proxy is used.

ValueBehavior
0Do not use a SOCKS proxy. This is the default.
4Connect through a SOCKS4 proxy.
5Connect through a SOCKS5 proxy.

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SoRcvBuf
-- intVal is an integer
local intVal = sftp.so_rcv_buf
sftp.so_rcv_buf = intVal

Specifies the socket receive-buffer size. The default is 4194304 bytes. Normally this property should remain unchanged.

When download throughput is unexpectedly low, testing a larger value may help. Values should generally be multiples of 4096.

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SoSndBuf
-- intVal is an integer
local intVal = sftp.so_snd_buf
sftp.so_snd_buf = intVal

Specifies the socket send-buffer size. The default is 262144 bytes. Normally this property should remain unchanged.

When upload throughput is unexpectedly low, testing values such as 524288 or 1048576 may help. Values should generally be multiples of 4096.

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SyncCreateAllLocalDirs
-- boolVal is a boolean
local boolVal = sftp.sync_create_all_local_dirs
sftp.sync_create_all_local_dirs = boolVal
Introduced in version 9.5.0.76

Controls whether SyncTreeDownload creates empty remote directories locally. The default is true.

When false, a local directory is created only when it is needed to contain a downloaded file.

When true, an empty remote directory is created locally even when no file beneath it is downloaded.

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SyncDirectives
-- strVal is a string
local strVal = sftp.sync_directives
sftp.sync_directives = strVal
Introduced in version 9.5.0.58

Specifies comma-separated directives that modify SyncTreeUpload or SyncTreeDownload. The default is an empty string.

DirectiveEffect
UploadIgnoreLocalOpenFailuresDuring upload synchronization, skip local files that cannot be opened, such as files held with exclusive access by another process.

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SyncMustMatch
-- strVal is a string
local strVal = sftp.sync_must_match
sftp.sync_must_match = strVal

Specifies a semicolon-separated list of wildcard filename patterns. SyncTreeUpload and SyncTreeDownload transfer only files matching at least one pattern.

This filter applies to filenames, not directory names encountered while recursively traversing a tree.

*.xml;*.txt;*.csv
Use * to match zero or more characters. Separate multiple patterns with semicolons.

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SyncMustMatchDir
-- strVal is a string
local strVal = sftp.sync_must_match_dir
sftp.sync_must_match_dir = strVal
Introduced in version 9.5.0.76

Specifies a semicolon-separated list of wildcard directory-name patterns. SyncTreeUpload and SyncTreeDownload enter only directories matching at least one pattern.

xml;txt;data_*
Use * to match zero or more characters. Separate multiple patterns with semicolons.

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SyncMustNotMatch
-- strVal is a string
local strVal = sftp.sync_must_not_match
sftp.sync_must_not_match = strVal

Specifies a semicolon-separated list of wildcard filename patterns. SyncTreeUpload and SyncTreeDownload skip files matching any pattern.

This filter applies to filenames, not directory names encountered while recursively traversing a tree.

*.tmp;*.bak;*.log
Use * to match zero or more characters. Separate multiple patterns with semicolons.

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SyncMustNotMatchDir
-- strVal is a string
local strVal = sftp.sync_must_not_match_dir
sftp.sync_must_not_match_dir = strVal
Introduced in version 9.5.0.76

Specifies a semicolon-separated list of wildcard directory-name patterns. SyncTreeUpload and SyncTreeDownload skip directories matching any pattern.

temp;cache;archive_*
Use * to match zero or more characters. Separate multiple patterns with semicolons.

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TcpNoDelay
-- boolVal is a boolean
local boolVal = sftp.tcp_no_delay
sftp.tcp_no_delay = boolVal

Controls the TCP_NODELAY socket option. The default is false. Set it to true to disable the Nagle algorithm and reduce delays when many small packets are sent.

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UncommonOptions
-- strVal is a string
local strVal = sftp.uncommon_options
sftp.uncommon_options = strVal
Introduced in version 9.5.0.73

Provides comma-separated compatibility, security, and synchronization options for uncommon scenarios. The default is an empty string and is appropriate for most applications.

KeywordEffect
ForceUserAuthRsaSha1Force legacy ssh-rsa/SHA-1 signatures for RSA user authentication. Set before connecting.
ProtectFromVpnOn Android, bypass an installed or active VPN.
NoSyncDownloadEmptyFilesPrevent empty files from being downloaded by SyncTreeDownload.
no-weak-mac-algsRemove weaker SHA-1, MD5, and RIPEMD-160 MAC algorithms from the offered list.
+ssh-hmac-etmRe-enable OpenSSH Encrypt-then-MAC algorithms disabled by default as a Terrapin mitigation.
+chacha20-poly1305@openssh.comRe-enable chacha20-poly1305@openssh.com, disabled by default as a Terrapin mitigation.

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UploadChunkSize
-- intVal is an integer
local intVal = sftp.upload_chunk_size
sftp.upload_chunk_size = intVal

Specifies the chunk size, in bytes, used by UploadFile and UploadFileByName. The default is 32000.

If an upload fails because the local operating system aborts the connection, try a smaller value such as 4096. Smaller chunks can reduce throughput.

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UserAuthBanner
-- strVal is a string
local strVal = sftp.user_auth_banner
sftp.user_auth_banner = strVal
Introduced in version 9.5.0.88

Contains a user-authentication banner received from the server. Check this property after StartKeyboardAuth or another authentication attempt and display it to the user when appropriate.

When no banner is available, the property returns an empty string.

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UtcMode
-- boolVal is a boolean
local boolVal = sftp.utc_mode
sftp.utc_mode = boolVal

Controls the time zone used by date/time getters. When true, returned values are expressed in UTC. When false (the default), returned values are converted to the local time zone.

UtcMode = false: Fri, 21 Nov 1997 09:55:06 -0600
UtcMode = true:  Fri, 21 Nov 1997 15:55:06 GMT

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VerboseLogging
-- boolVal is a boolean
local boolVal = sftp.verbose_logging
sftp.verbose_logging = boolVal

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
-- strVal is a string (read-only)
local strVal = sftp.version

Version of the component/library, such as "10.1.0"

More Information and Examples
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XferByteCount
-- intVal is an integer (read-only)
local intVal = sftp.xfer_byte_count
Introduced in version 9.5.0.71

Contains the current transfer byte count for an upload or download in progress. An application can read this property while an asynchronous transfer is running.

For SyncTreeUpload and SyncTreeDownload, the value is cumulative across all files processed by the operation. Use XferByteCount64 when a 64-bit count is required.

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XferByteCount64
-- intVal is an integer (read-only)
local intVal = sftp.xfer_byte_count64
Introduced in version 9.5.0.71

Contains the current 64-bit transfer byte count for an upload or download in progress. An application can read this property while an asynchronous transfer is running.

For SyncTreeUpload and SyncTreeDownload, the value is cumulative across all files processed by the operation.

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Methods

AuthenticatePk
-- username is a string
-- private_key is a chilkat.SshKey
-- ok is true, or nil and err on failure
local ok, err = sftp:authenticate_pk(username, private_key)

Authenticates the connected SSH session using public-key authentication. username identifies the server account, and privateKey must contain the corresponding private key. The matching public key must already be authorized for that account on the server.

Call Connect first. After a failure, inspect AuthFailReason and LastErrorText.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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AuthenticatePw
-- login is a string
-- password is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:authenticate_pw(login, password)

Authenticates the connected SSH session using login and password.

1. Connect
2. AuthenticatePw or AuthenticatePk
3. InitializeSftp

If the server requests a password change, see PasswordChangeRequested. After a failure, inspect AuthFailReason and LastErrorText.

A rejected password does not necessarily close the SSH connection. The application may retry authentication on the same connected session. After a later success, an older AuthFailReason value can remain populated.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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AuthenticatePwPk
-- username is a string
-- password is a string
-- private_key is a chilkat.SshKey
-- ok is true, or nil and err on failure
local ok, err = sftp:authenticate_pw_pk(username, password, private_key)

Authenticates with a server that requires both a password and a private key. username identifies the account, password supplies the password, and privateKey supplies the private key.

Most servers require either password or public-key authentication rather than both. After a failure, inspect AuthFailReason and LastErrorText.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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AuthenticateSecPw
-- login is a chilkat.SecureString
-- password is a chilkat.SecureString
-- ok is true, or nil and err on failure
local ok, err = sftp:authenticate_sec_pw(login, password)
Introduced in version 9.5.0.71

Works like AuthenticatePw, but receives login and password in SecureString objects.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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AuthenticateSecPwPk
-- username is a chilkat.SecureString
-- password is a chilkat.SecureString
-- private_key is a chilkat.SshKey
-- ok is true, or nil and err on failure
local ok, err = sftp:authenticate_sec_pw_pk(username, password, private_key)
Introduced in version 9.5.0.71

Works like AuthenticatePwPk, but receives username and password in SecureString objects. privateKey supplies the private key.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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ClearCache
sftp:clear_cache()

Clears the internal remote file-attribute cache used when EnableCache is true.

More Information and Examples
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ClearSessionLog
sftp:clear_session_log()

Clears the in-memory text stored in SessionLog.

More Information and Examples
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CloseHandle
-- handle is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:close_handle(handle)

Closes the remote file or directory handle specified by handle. The handle must have been returned by OpenFile or OpenDir.

Handles are specific to one initialized SFTP session. Close each handle exactly once. Closing an empty, invalid, or already-closed handle returns false. A handle must never be reused after disconnecting or replacing the connection.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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Connect
-- domain_name is a string
-- port is an integer
-- ok is true, or nil and err on failure
local ok, err = sftp:connect(domain_name, port)

Establishes an SSH connection to domainName on TCP port port. The host may be a DNS name or numeric IPv4 or IPv6 address; SSH servers commonly listen on port 22.

A successful connection establishes the SSH transport only. Next call an authentication method, then call InitializeSftp.
1. Connect
2. AuthenticatePw, AuthenticatePk, or another authentication method
3. InitializeSftp
4. Perform SFTP operations

Supported negotiation algorithms include:

CategoryAlgorithms
Host keyssh-ed25519, rsa-sha2-256, rsa-sha2-512, ecdsa-sha2-nistp256, ecdsa-sha2-nistp384, ecdsa-sha2-nistp521, ssh-rsa, ssh-dss
Key exchangecurve25519-sha256, curve25519-sha256@libssh.org, NIST ECDH, Diffie-Hellman group 1/14/16/18, and group-exchange SHA-1/SHA-256
CiphersAES CTR/CBC/GCM, Twofish CBC, Blowfish CBC, and optionally chacha20-poly1305@openssh.com
MACSHA-2, SHA-1, RIPEMD-160, MD5, and optionally OpenSSH Encrypt-then-MAC variants
Compressionnone, zlib, and zlib@openssh.com
Connection failures can occur before SSH negotiation because of firewalls, endpoint security, routing, network ACLs, proxy configuration, or server policy.
Calling while connected: A new successful Connect replaces the existing SSH connection. The previous SFTP subsystem and all handles from it are no longer usable. Authenticate and call InitializeSftp for the new connection.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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ConnectThroughSsh
-- ssh_conn is a chilkat.Ssh
-- hostname is a string
-- port is an integer
-- ok is true, or nil and err on failure
local ok, err = sftp:connect_through_ssh(ssh_conn, hostname, port)
Introduced in version 9.5.0.55

Connects to hostname on port through the already connected and authenticated Ssh object in sshConn.

application  →  first SSH server  →  destination SSH/SFTP server

After this method succeeds, authenticate separately with the destination server and call InitializeSftp. All destination traffic is carried through the first SSH connection.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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ContinueKeyboardAuth
-- response is a string
-- str is a string, or nil and err on failure
local str, err = sftp:continue_keyboard_auth(response)
Introduced in version 9.5.0.88

Continues keyboard-interactive authentication by submitting response for the prompts returned by StartKeyboardAuth.

For a single prompt, pass the response text directly. For multiple prompts, pass XML in this form:

<response>
  <response1>response to first prompt</response1>
  <response2>response to second prompt</response2>
  ...
</response>

The returned XML indicates authentication success, authentication failure, or another infoRequest containing additional prompts.

<success>success message</success>

<error>error message</error>

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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CopyFileAttr
-- local_filename is a string
-- remote_filename is a string
-- is_handle is a boolean
-- ok is true, or nil and err on failure
local ok, err = sftp:copy_file_attr(local_filename, remote_filename, is_handle)

Copies supported timestamps and attributes from the local file at localFilename to the remote item identified by remoteFilename.

Set isHandle to true when remoteFilename contains an open SFTP handle; otherwise set it to false for a remote path.

Negotiated SFTP versionAttributes copied
SFTP v3 and earlierLast-modified time and last-access time
SFTP v4 and v5Last-modified time, last-access time, and creation time
SFTP v6 and laterThe preceding timestamps plus read-only, hidden, archive, compressed, and encrypted flags
The remote server and filesystem determine whether all requested attributes can be applied. Last-access time may change when the server accesses the file, and compressed or encrypted flags may not have the same effect on every server.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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CreateDir
-- path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:create_dir(path)

Creates the remote directory specified by path. Parent directories are not necessarily created automatically.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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Disconnect
sftp:disconnect()

Closes the current SSH/SFTP connection. All remote file and directory handles from that session become invalid and must not be reused.

The object remains reusable. A later session must call Connect, authenticate again, and call InitializeSftp before performing SFTP operations.

Some properties retain values from the previous session after disconnect, including the negotiated protocol version, server identifier, and last SFTP status. Treat these as historical values rather than evidence of a live session.
More Information and Examples
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DownloadBd
-- remote_file_path is a string
-- bin_data is a chilkat.BinData
-- ok is true, or nil and err on failure
local ok, err = sftp:download_bd(remote_file_path, bin_data)
Introduced in version 9.5.0.62

Downloads the remote file at remoteFilePath and appends its bytes to binData.

Existing data in binData is preserved. Clear it first when replacement rather than append behavior is required.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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DownloadFile
-- handle is a string
-- to_filename is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:download_file(handle, to_filename)

Streams the remote file identified by handle to the local filesystem path toFilename. The handle must have been returned by OpenFile.

The transfer is streamed and is not limited by available memory. Close the remote handle when the download is complete.

This method downloads the entire remote file beginning at byte offset 0. It does not begin at the handle's current sequential read position.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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DownloadFileByName
-- remote_file_path is a string
-- local_file_path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:download_file_by_name(remote_file_path, local_file_path)

Downloads the remote file at remoteFilePath to the local filesystem path localFilePath.

When PreserveDate is true, Chilkat preserves the remote file's last-modified time.

An absolute remote path begins with / and is relative to the server filesystem root. A relative path is interpreted relative to the authenticated user's home directory.
If the local destination file exists, it is truncated before the download.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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DownloadSb
-- remote_file_path is a string
-- charset is a string
-- sb is a chilkat.StringBuilder
-- ok is true, or nil and err on failure
local ok, err = sftp:download_sb(remote_file_path, charset, sb)
Introduced in version 9.5.0.62

Downloads the remote file at remoteFilePath, decodes it using charset, and appends the text to sb.

Existing text in sb is preserved. Clear it first when replacement rather than append behavior is required.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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Eof
-- handle is a string
-- flag is true or false
local flag = sftp:eof(handle)

Returns true when the most recent read for handle received the SFTP end-of-file status.

Reading exactly through the final byte does not set EOF immediately. The next read returns successfully with zero bytes, sets LastStatusCode to SSH_FX_EOF, and causes this method to return true.

An empty, malformed, or already-closed handle can also cause this method to return true. Use LastReadFailed and the read method's result to distinguish a normal EOF from a handle or read failure.

Returns true or false: an answer, not a success flag.

More Information and Examples
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FileExists
-- remote_path is a string
-- follow_links is a boolean
-- n is an integer
local n = sftp:file_exists(remote_path, follow_links)
Introduced in version 9.5.0.67

Checks the remote item at remotePath. When followLinks is true, a symbolic link is followed and the target type is returned.

Return valueMeaning
-1Unable to determine the result. Inspect LastErrorText.
0The path does not exist.
1A regular file exists.
2A directory exists.
3A symbolic link exists. This is possible only when followLinks is false.
4A special filesystem entry exists.
5An entry of unknown type exists.
6A socket exists.
7A character device exists.
8A block device exists.
9A FIFO exists.
Positive values correspond to SFTP filesystem entry types. Some types are platform-dependent.
For a dangling symbolic link, followLinks = false returns 3 for the link itself, while followLinks = true returns 0 because the target does not exist.
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Fsync
-- handle is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:fsync(handle)
Introduced in version 9.5.0.71

Requests that the server flush pending data for the open file identified by handle to stable storage.

This method uses the OpenSSH fsync@openssh.com extension and succeeds only when the server supports that extension.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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GetFileCreateTimeStr
-- path_or_handle is a string
-- b_follow_links is a boolean
-- b_is_handle is a boolean
-- str is a string, or nil and err on failure
local str, err = sftp:get_file_create_time_str(path_or_handle, b_follow_links, b_is_handle)

Returns the remote file's creation date and time. pathOrHandle may contain a remote path or a handle returned by OpenFile. Set bIsHandle to true for a handle and false for a path.

When bFollowLinks is true, the server follows a symbolic link and returns metadata for its target.

SFTP v3 and earlier do not provide a file creation time.

The result is an RFC 822 formatted string, for example Fri, 21 Nov 1997 09:55:06 -0600.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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GetFileGroup
-- path_or_handle is a string
-- b_follow_links is a boolean
-- b_is_handle is a boolean
-- str is a string, or nil and err on failure
local str, err = sftp:get_file_group(path_or_handle, b_follow_links, b_is_handle)

Returns the remote file's group ownership. pathOrHandle may contain a remote path or a handle returned by OpenFile. Set bIsHandle to true for a handle and false for a path.

When bFollowLinks is true, the server follows a symbolic link and returns metadata for its target.

With SFTP v3 and earlier, the result is the decimal numeric GID because textual group names are not supported.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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GetFileLastAccessStr
-- path_or_handle is a string
-- b_follow_links is a boolean
-- b_is_handle is a boolean
-- str is a string, or nil and err on failure
local str, err = sftp:get_file_last_access_str(path_or_handle, b_follow_links, b_is_handle)

Returns the remote file's last-access date and time. pathOrHandle may contain a remote path or a handle returned by OpenFile. Set bIsHandle to true for a handle and false for a path.

When bFollowLinks is true, the server follows a symbolic link and returns metadata for its target.

The result is an RFC 822 formatted string, for example Fri, 21 Nov 1997 09:55:06 -0600.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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GetFileLastModifiedStr
-- path_or_handle is a string
-- b_follow_links is a boolean
-- b_is_handle is a boolean
-- str is a string, or nil and err on failure
local str, err = sftp:get_file_last_modified_str(path_or_handle, b_follow_links, b_is_handle)

Returns the remote file's last-modified date and time. pathOrHandle may contain a remote path or a handle returned by OpenFile. Set bIsHandle to true for a handle and false for a path.

When bFollowLinks is true, the server follows a symbolic link and returns metadata for its target.

The result is an RFC 822 formatted string, for example Fri, 21 Nov 1997 09:55:06 -0600.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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GetFileOwner
-- path_or_handle is a string
-- b_follow_links is a boolean
-- b_is_handle is a boolean
-- str is a string, or nil and err on failure
local str, err = sftp:get_file_owner(path_or_handle, b_follow_links, b_is_handle)

Returns the remote file's owner. pathOrHandle may contain a remote path or a handle returned by OpenFile. Set bIsHandle to true for a handle and false for a path.

When bFollowLinks is true, the server follows a symbolic link and returns metadata for its target.

With SFTP v3 and earlier, the result is the decimal numeric UID because textual owner names are not supported.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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GetFilePermissions
-- path_or_handle is a string
-- b_follow_links is a boolean
-- b_is_handle is a boolean
-- n is an integer
local n = sftp:get_file_permissions(path_or_handle, b_follow_links, b_is_handle)

Returns the remote item's complete POSIX mode value. pathOrHandle may contain a remote path or a handle returned by OpenFile. Set bIsHandle to true for a handle and false for a path. When bFollowLinks is true, the server follows a symbolic link and returns metadata for its target.

The returned integer includes both the file-type bits and permission bits. For example:

Regular file, mode 0664: octal 0100664, decimal 33204
Regular file, mode 0600: octal 0100600, decimal 33152
Regular file, mode 0644: octal 0100644, decimal 33188

Mask with octal 07777 to obtain permission and special bits, or 0777 for only the traditional owner/group/other read, write, and execute bits. See SetPermissions to change the permissions.

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GetFileSize32
-- path_or_handle is a string
-- b_follow_links is a boolean
-- b_is_handle is a boolean
-- n is an integer
local n = sftp:get_file_size32(path_or_handle, b_follow_links, b_is_handle)

Returns the remote file's size in bytes as a 32-bit integer. pathOrHandle may contain a remote path or a handle returned by OpenFile. Set bIsHandle to true for a handle and false for a path.

When bFollowLinks is true, the server follows a symbolic link and returns metadata for its target.

Returns -1 when the size cannot be represented as a 32-bit integer. Use GetFileSize64 or GetFileSizeStr for large files.
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GetFileSize64
-- path_or_handle is a string
-- b_follow_links is a boolean
-- b_is_handle is a boolean
-- n is an integer
local n = sftp:get_file_size64(path_or_handle, b_follow_links, b_is_handle)

Returns the remote file's size in bytes as a 64-bit integer. pathOrHandle may contain a remote path or a handle returned by OpenFile. Set bIsHandle to true for a handle and false for a path.

When bFollowLinks is true, the server follows a symbolic link and returns metadata for its target.

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GetFileSizeStr
-- path_or_handle is a string
-- b_follow_links is a boolean
-- b_is_handle is a boolean
-- str is a string, or nil and err on failure
local str, err = sftp:get_file_size_str(path_or_handle, b_follow_links, b_is_handle)

Returns the remote file's size in bytes as a decimal string. pathOrHandle may contain a remote path or a handle returned by OpenFile. Set bIsHandle to true for a handle and false for a path.

When bFollowLinks is true, the server follows a symbolic link and returns metadata for its target.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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GetHostKeyFP
-- hash_alg is a string
-- include_key_type is a boolean
-- include_hash_name is a boolean
-- str is a string, or nil and err on failure
local str, err = sftp:get_host_key_fp(hash_alg, include_key_type, include_hash_name)
Introduced in version 9.5.0.92

Returns the connected server's host-key fingerprint using hashAlg. Common choices include SHA256, SHA384, SHA512, SHA1, and MD5.

includeKeyTypeincludeHashNameExample format
truetruessh-rsa SHA256:L7sQgnpnoBwRoyIYXAFBs8SdSnwtyYmhXs1p/mQDK...
truefalsessh-rsa L7sQgnpnoBwRoyIYXAFBs8SdSnwtyYmhXs1p/mQDK...
falsetrueSHA256:L7sQgnpnoBwRoyIYXAFBs8SdSnwtyYmhXs1p/mQDK...
falsefalseL7sQgnpnoBwRoyIYXAFBs8SdSnwtyYmhXs1p/mQDK...
For server identity verification, compare a SHA-256 fingerprint with a value obtained from a trusted source before sending credentials.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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GetLastJsonData
-- json is a chilkat.JsonObject
sftp:get_last_json_data(json)
Introduced in version 11.0.0

Populates json with supplemental details produced by the most recent method when such details are available. Many methods do not produce additional JSON information.

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GetSyncedFiles
-- str_tab is a chilkat.StringTable
sftp:get_synced_files(str_tab)
Introduced in version 10.0.0

Appends to strTab the relative paths processed by the most recent SyncTreeUpload or SyncTreeDownload operation.

For downloads, entries can include local directories that were created. Directory paths end with / so they can be distinguished from file paths.

Existing entries in strTab are preserved.
Clear strTab first when only the latest synchronization results are wanted. Downloaded directory entries are reported with a trailing /; uploaded directory entries are reported without one.
More Information and Examples
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HardLink
-- old_path is a string
-- new_path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:hard_link(old_path, new_path)
Introduced in version 9.5.0.71

Creates a hard link from newPath to the existing remote file at oldPath.

This method uses the OpenSSH hardlink@openssh.com extension and succeeds only when the server supports that extension.
A successful hard link refers to the same underlying file. Modifying the existing file through either path changes the content observed through the other path.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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InitializeSftp
-- ok is true, or nil and err on failure
local ok, err = sftp:initialize_sftp()

Opens the SFTP subsystem and negotiates the SFTP protocol version. Call this method after connecting and authenticating.

1. Connect
2. AuthenticatePw, AuthenticatePk, or another authentication method
3. InitializeSftp

After success, read ProtocolVersion to determine the negotiated SFTP version.

If opening the SFTP channel fails, inspect InitializeFailCode, InitializeFailReason, and LastErrorText.
Call this method only once for a given SSH connection. A second call on the same connection returns false. After disconnecting or replacing the connection, authenticate the new connection and call this method again.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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LastReadFailed
-- handle is a string
-- flag is true or false
local flag = sftp:last_read_failed(handle)

Returns true if the most recent read associated with handle failed; otherwise returns false.

A normal end-of-file is not a read failure: the EOF read succeeds, returns zero bytes, and this method returns false. For an empty, malformed, or already-closed handle, this method returns true.

Returns true or false: an answer, not a success flag.

More Information and Examples
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LastReadNumBytes
-- handle is a string
-- n is an integer
local n = sftp:last_read_num_bytes(handle)

Returns the number of bytes received by the most recent read associated with handle.

The initial value for a newly opened handle is 0. A normal EOF read and a failed read report 0.

More Information and Examples
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OpenDir
-- path is a string
-- str is a string, or nil and err on failure
local str, err = sftp:open_dir(path)

Opens the remote directory specified by path and returns a handle for reading its entries.

handle = OpenDir(path)
ReadDirListing(handle, dirObj)
CloseHandle(handle)

Remote paths use / as the separator. A path beginning with / is absolute; a relative path is interpreted relative to the authenticated user's home directory. An empty path refers to that default directory.

This method does not change a working directory. SFTP is not FTP and has no persistent current-directory command.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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OpenFile
-- remote_path is a string
-- access is a string
-- create_disposition is a string
-- str is a string, or nil and err on failure
local str, err = sftp:open_file(remote_path, access, create_disposition)

Opens or creates the remote file at remotePath and returns a handle for subsequent read or write operations. Close the handle with CloseHandle when finished.

access must be readOnly, writeOnly, or readWrite.

createDisposition is a comma-separated list. It must contain exactly one primary disposition:

Primary dispositionBehavior
createNewCreate a new file; fail if it already exists.
createTruncateCreate a new file, or open and truncate an existing file.
openExistingOpen an existing file; fail if it does not exist.
openOrCreateOpen the file if it exists, otherwise create it.
truncateExistingOpen and truncate an existing file; fail if it does not exist.

Additional optional keywords are:

OptionBehavior
appendDataWrite at the end of the file. Appends are not guaranteed to be atomic.
appendDataAtomicAppend atomically so concurrent appenders do not collide. SFTP v5 or later.
textModeRequest server text-mode processing and canonical newline conversion. SFTP v5 or later.
blockReadRequest exclusive read access. SFTP v5 or later.
blockWriteRequest exclusive write access. SFTP v5 or later.
blockDeletePrevent deletion while the handle is open. SFTP v5 or later.
blockAdvisoryMake the requested block modes advisory. SFTP v5 or later.
noFollowFail if the final path component is a symbolic link. SFTP v5 or later.
deleteOnCloseRequest deletion when the last handle is closed. SFTP v5 or later.
accessAuditAlarmInfoRequest privileges needed to read or write AUDIT or ALARM ACL entries. SFTP v5 or later.
accessBackupRequest backup/restore privileges that may bypass normal access checks. SFTP v5 or later.
backupStreamRead or write a server-specific backup stream. SFTP v5 or later.
Options marked SFTP v5 or later require ForceV3 to be false and a negotiated ProtocolVersion of at least 5.
An absolute remote path begins with /. A relative path is interpreted from the authenticated user's home directory. Some servers require a filename in the home directory to be written as ./filename.
Use only documented values: Some servers or Chilkat versions may tolerate an unknown access value, an unknown option, or conflicting primary dispositions, but the resulting behavior is unspecified. Supply one documented access value and exactly one primary disposition.
appendData forces writes to the end of the file, including explicit-offset writes. By itself it opens an existing file but does not create a missing file; combine it with an appropriate primary disposition when creation is required. Options defined for SFTP v5 or later must not be assumed to take effect when an older version is negotiated, even if the open request succeeds.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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ReadDirListing
-- handle is a string
-- dir_obj is a chilkat.SFtpDir
-- ok is true, or nil and err on failure
local ok, err = sftp:read_dir_listing(handle, dir_obj)
Introduced in version 11.0.0

Reads all remaining directory entries from handle, which must have been returned by OpenDir, and stores them in dirObj. Entries are returned in server order; Chilkat does not sort the listing.

After end-of-directory has been reached, another call on the same handle returns true, adds no entries, and sets LastStatusCode to SSH_FX_EOF.

This method does not clear dirObj. Use a new or cleared SFtpDir object when an empty result must replace an earlier listing. Close the directory handle when finished.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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ReadFileBd
-- handle is a string
-- num_bytes is an integer
-- bd is a chilkat.BinData
-- ok is true, or nil and err on failure
local ok, err = sftp:read_file_bd(handle, num_bytes, bd)
Introduced in version 9.5.0.77

Reads up to numBytes bytes from the current position of the remote file identified by handle and appends them to bd. The handle must have been returned by OpenFile.

Fewer bytes can be read when end-of-file is reached. Repeat the call until Eof(handle) returns true to read the entire file incrementally.

This method shares the handle's sequential read position with ReadFileBytes and ReadFileText. Existing bytes in bd are preserved.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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ReadFileText
-- handle is a string
-- num_bytes is an integer
-- charset is a string
-- str is a string, or nil and err on failure
local str, err = sftp:read_file_text(handle, num_bytes, charset)

Reads up to numBytes bytes from the current position of handle, decodes the bytes using charset, and returns the resulting text.

See Supported Charsets.

The requested size is measured in bytes, not characters. With a multibyte encoding such as UTF-8 or Shift_JIS, the final character can be split across calls. For robust streaming, read raw bytes and decode with application-maintained state.
Multibyte boundaries: Chilkat does not retain an incomplete multibyte character between calls. If numBytes ends in the middle of a UTF-8 sequence, the first returned string ends with the incomplete bytes and the next call begins with the remaining bytes. Choose byte counts that end on character boundaries, or read bytes and perform streaming decoding in the application.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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ReadFileText32
-- handle is a string
-- offset is an integer
-- num_bytes is an integer
-- charset is a string
-- str is a string, or nil and err on failure
local str, err = sftp:read_file_text32(handle, offset, num_bytes, charset)

Reads up to numBytes bytes from handle at the 32-bit byte offset, decodes the bytes using charset, and returns the resulting text.

See Supported Charsets.

The requested size is measured in bytes, not characters. With a multibyte encoding such as UTF-8 or Shift_JIS, the final character can be split across calls. For robust streaming, read raw bytes and decode with application-maintained state.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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ReadFileText64
-- handle is a string
-- offset is an integer
-- num_bytes is an integer
-- charset is a string
-- str is a string, or nil and err on failure
local str, err = sftp:read_file_text64(handle, offset, num_bytes, charset)

Reads up to numBytes bytes from handle at the 64-bit byte offset, decodes the bytes using charset, and returns the resulting text.

See Supported Charsets.

The requested size is measured in bytes, not characters. With a multibyte encoding such as UTF-8 or Shift_JIS, the final character can be split across calls. For robust streaming, read raw bytes and decode with application-maintained state.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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ReadFileText64s
-- handle is a string
-- offset is a string
-- num_bytes is an integer
-- charset is a string
-- str is a string, or nil and err on failure
local str, err = sftp:read_file_text64s(handle, offset, num_bytes, charset)

Reads up to numBytes bytes from handle at the byte offset supplied as decimal string offset, decodes the bytes using charset, and returns the resulting text.

See Supported Charsets.

The requested size is measured in bytes, not characters. With a multibyte encoding, the final character can be split across calls.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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ReadLink
-- path is a string
-- str is a string, or nil and err on failure
local str, err = sftp:read_link(path)
Introduced in version 9.5.0.71

Returns the target path stored in the symbolic link at remote path.

The returned value is the target string stored in the link. It is not automatically canonicalized and can be relative, absolute, or refer to a nonexistent target.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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RealPath
-- original_path is a string
-- compose_path is a string
-- str is a string, or nil and err on failure
local str, err = sftp:real_path(original_path, compose_path)

Asks the server to canonicalize originalPath and returns the resulting absolute remote path.

For SFTP v5 or later, composePath may optionally modify or extend the original path; pass an empty string when no composition is needed. If composePath is absolute, it replaces originalPath.

SFTP v3 and v4 do not support path composition. On those versions, composePath is ignored and the method canonicalizes only originalPath.

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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RemoveDir
-- path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:remove_dir(path)

Deletes the remote directory specified by path.

Most SFTP servers require the directory to be empty before it can be removed.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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RemoveFile
-- filename is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:remove_file(filename)

Deletes the remote file specified by filename.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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RenameFileOrDir
-- old_path is a string
-- new_path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:rename_file_or_dir(old_path, new_path)

Renames or moves a remote file or directory from oldPath to newPath.

oldPath: someDirA/filename
newPath: someDirB/abc/xyz/filename

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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ResumeDownloadFileByName
-- remote_file_path is a string
-- local_file_path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:resume_download_file_by_name(remote_file_path, local_file_path)

Resumes downloading remoteFilePath to the local filesystem path localFilePath. Chilkat uses only the existing local file size as the remote starting offset.

  • If the local file is missing or empty, a normal download is performed.
  • If it is smaller, the remaining remote bytes are appended after the existing local length.
  • If it is the same size or larger, the method treats the download as complete and does not truncate or verify the local content.
Important: The existing local bytes are not compared with the remote source. Before resuming, the application must ensure that the local file is the correct prefix of the remote file.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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ResumeUploadFileByName
-- remote_file_path is a string
-- local_file_path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:resume_upload_file_by_name(remote_file_path, local_file_path)

Resumes uploading the local file at localFilePath to remoteFilePath. Chilkat uses only the existing remote file size as the local starting offset.

  • If the remote file is missing or empty, a normal upload is performed.
  • If it is smaller, the remaining local bytes are appended after the existing remote length.
  • If it is the same size or larger, the method treats the upload as complete and does not truncate or verify the remote content.
Important: The existing remote bytes are not compared with the local source. Before resuming, the application must ensure that the remote file is the correct prefix of the local file.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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SendIgnore
-- ok is true, or nil and err on failure
local ok, err = sftp:send_ignore()
Introduced in version 9.5.0.66

Sends an SSH IGNORE message. No SFTP file handle or channel is required.

The server does not send a reply, but a successful send helps verify that the SSH connection is still writable.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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SetAllowedAlgorithms
-- json is a chilkat.JsonObject
-- ok is true, or nil and err on failure
local ok, err = sftp:set_allowed_algorithms(json)
Introduced in version 9.5.0.99

Configures the exact set of SSH algorithms permitted for subsequent connections using the settings in json.

Call this method before Connect. The connection fails when no mutually supported algorithm remains in a required category.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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SetCreateDt
-- path_or_handle is a string
-- is_handle is a boolean
-- create_date_time is a chilkat.DateTime
-- ok is true, or nil and err on failure
local ok, err = sftp:set_create_dt(path_or_handle, is_handle, create_date_time)

Sets the remote file's creation date and time. pathOrHandle may contain a remote path or an open handle. Set isHandle to true for a handle and false for a path.

SFTP v3 and earlier do not support setting creation time.

createDateTime supplies the new value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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SetCreateTimeStr
-- path_or_handle is a string
-- b_is_handle is a boolean
-- date_time_str is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:set_create_time_str(path_or_handle, b_is_handle, date_time_str)

Sets the remote file's creation date and time. pathOrHandle may contain a remote path or an open handle. Set bIsHandle to true for a handle and false for a path.

Pass the value in dateTimeStr as an RFC 822 formatted string, for example Fri, 21 Nov 1997 09:55:06 -0600.

SFTP v3 and earlier do not support setting creation time.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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SetLastAccessDt
-- path_or_handle is a string
-- is_handle is a boolean
-- access_date_time is a chilkat.DateTime
-- ok is true, or nil and err on failure
local ok, err = sftp:set_last_access_dt(path_or_handle, is_handle, access_date_time)

Sets the remote file's last-access date and time. pathOrHandle may contain a remote path or an open handle. Set isHandle to true for a handle and false for a path.

accessDateTime supplies the new value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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SetLastAccessTimeStr
-- path_or_handle is a string
-- b_is_handle is a boolean
-- date_time_str is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:set_last_access_time_str(path_or_handle, b_is_handle, date_time_str)

Sets the remote file's last-access date and time. pathOrHandle may contain a remote path or an open handle. Set bIsHandle to true for a handle and false for a path.

Pass the value in dateTimeStr as an RFC 822 formatted string, for example Fri, 21 Nov 1997 09:55:06 -0600.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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SetLastModifiedDt
-- path_or_handle is a string
-- is_handle is a boolean
-- modified_date_time is a chilkat.DateTime
-- ok is true, or nil and err on failure
local ok, err = sftp:set_last_modified_dt(path_or_handle, is_handle, modified_date_time)

Sets the remote file's last-modified date and time. pathOrHandle may contain a remote path or an open handle. Set isHandle to true for a handle and false for a path.

modifiedDateTime supplies the new value.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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SetLastModifiedTimeStr
-- path_or_handle is a string
-- b_is_handle is a boolean
-- date_time_str is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:set_last_modified_time_str(path_or_handle, b_is_handle, date_time_str)

Sets the remote file's last-modified date and time. pathOrHandle may contain a remote path or an open handle. Set bIsHandle to true for a handle and false for a path.

Pass the value in dateTimeStr as an RFC 822 formatted string, for example Fri, 21 Nov 1997 09:55:06 -0600.

When SFTP v3 is negotiated, the stored timestamp has whole-second precision.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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SetOwnerAndGroup
-- path_or_handle is a string
-- is_handle is a boolean
-- owner is a string
-- group is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:set_owner_and_group(path_or_handle, is_handle, owner, group)

Sets the owner and group of the remote item identified by pathOrHandle. Set isHandle to true for an open handle and false for a remote path.

owner and group supply the new textual owner and group values.

SFTP v3 and earlier do not support textual owner and group names.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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SetPermissions
-- path_or_handle is a string
-- is_handle is a boolean
-- permissions is an integer
-- ok is true, or nil and err on failure
local ok, err = sftp:set_permissions(path_or_handle, is_handle, permissions)

Sets the POSIX permission bits for the remote item identified by pathOrHandle. Set isHandle to true for an open handle and false for a remote path.

Pass the permission bits, not the file-type bits. In languages supporting octal integer literals, common values include 0600, 0644, and 0755. Their decimal equivalents are 384, 420, and 493.

After setting permissions, GetFilePermissions returns the complete mode, including the file-type bits. For example, setting 0644 on a regular file can subsequently return 0100644.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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StartKeyboardAuth
-- login is a string
-- str is a string, or nil and err on failure
local str, err = sftp:start_keyboard_auth(login)
Introduced in version 9.5.0.88

Begins keyboard-interactive authentication for login and returns XML describing the server's prompts.

<infoRequest numPrompts="N">
  <name>name_string</name>
  <instruction>instruction_string</instruction>
  <prompt1 echo="1_or_0">prompt_string</prompt1>
  ...
  <promptN echo="1_or_0">prompt_string</promptN>
</infoRequest>

The echo attribute indicates whether the response may be displayed while entered. A value of 0 normally identifies secret input such as a password.

If authentication immediately succeeds or fails, the result has one of these forms:

<success>success message</success>

<error>error message</error>

Returns the string, or nil, err on failure (or when nothing is found). The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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SymLink
-- old_path is a string
-- new_path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:sym_link(old_path, new_path)
Introduced in version 9.5.0.71

Creates a symbolic link on the server. oldPath identifies the link target and newPath identifies the new symbolic-link path.

The server's SFTP implementation determines path interpretation and whether symbolic links are permitted.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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SyncTreeDownload
-- remote_root is a string
-- local_root is a string
-- mode is an integer
-- recurse is a boolean
-- ok is true, or nil and err on failure
local ok, err = sftp:sync_tree_download(remote_root, local_root, mode, recurse)

Synchronizes files from the remote directory remoteRoot to the local filesystem directory localRoot.

ModeBehavior
0Download all files.
1Download files that do not exist locally.
2Download files that are newer remotely or missing locally.
3Download only files that are newer remotely; do not download missing local files.
5Download files that are missing locally or differ in size.
6Mode 5 plus files that are newer remotely.
99Do not download; delete remote files that do not exist locally.

Set recurse to true to descend into subdirectories. An absolute remote path begins with /; a relative path is interpreted from the authenticated user's home directory.

Use GetSyncedFiles after the operation to retrieve the relative paths that were downloaded or created.

With SyncCreateAllLocalDirs set to true, mode 0 creates empty remote directories locally. Mode 1 downloads only missing local files and preserves existing local files. Mode 99 deletes files from the remote tree that are absent locally; it does not delete extra local files.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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SyncTreeUpload
-- local_base_dir is a string
-- remote_base_dir is a string
-- mode is an integer
-- b_recurse is a boolean
-- ok is true, or nil and err on failure
local ok, err = sftp:sync_tree_upload(local_base_dir, remote_base_dir, mode, b_recurse)

Synchronizes files from the local filesystem directory localBaseDir to the remote directory remoteBaseDir.

ModeBehavior
0Upload all files.
1Upload files that do not exist remotely.
2Upload files that are newer locally or missing remotely.
3Upload only files that are newer locally; do not upload missing remote files.
4Upload files that are missing remotely or differ in size.
5Mode 4 plus files that are newer locally.

Set bRecurse to true to descend into subdirectories. An absolute remote path begins with /; a relative path is interpreted from the authenticated user's home directory.

Use GetSyncedFiles after the operation to retrieve the relative paths that were uploaded.

Mode 0 also creates empty remote directories. Mode 1 uploads only missing files and does not replace an existing remote file merely because the local file is newer; use mode 2 for missing-or-newer behavior. The filename and directory filters are applied during recursive traversal.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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UploadBd
-- bin_data is a chilkat.BinData
-- remote_file_path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:upload_bd(bin_data, remote_file_path)
Introduced in version 9.5.0.62

Uploads all bytes in binData to the remote file at remoteFilePath.

If the destination exists, it is truncated before the bytes are uploaded.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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UploadFile
-- handle is a string
-- from_local_file_path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:upload_file(handle, from_local_file_path)

Streams the local filesystem file at fromLocalFilePath to the remote file identified by handle. The handle must have been returned by OpenFile.

Close the remote handle when the upload is complete.

The upload begins at the handle's current sequential write position. Existing bytes before that position are preserved unless the file was truncated when opened.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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UploadFileByName
-- remote_file_path is a string
-- local_file_path is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:upload_file_by_name(remote_file_path, local_file_path)

Uploads the local filesystem file at localFilePath to remoteFilePath.

When PreserveDate is true, Chilkat preserves the local file's last-modified time on the remote file.

An absolute remote path begins with / and is relative to the server filesystem root. A relative path is interpreted relative to the authenticated user's home directory.
If the destination exists, it is truncated before the upload. A zero-byte local file creates or truncates the remote file to zero bytes. Missing remote parent directories are not created automatically.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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UploadSb
-- sb is a chilkat.StringBuilder
-- remote_file_path is a string
-- charset is a string
-- include_bom is a boolean
-- ok is true, or nil and err on failure
local ok, err = sftp:upload_sb(sb, remote_file_path, charset, include_bom)
Introduced in version 9.5.0.62

Encodes the text in sb using charset and uploads it to remoteFilePath.

Set includeBom to true to prepend a byte-order mark when the selected encoding supports one.

If the destination exists, it is truncated before the text is uploaded. For utf-8, setting includeBom to true prepends the three bytes EF BB BF; setting it to false omits them.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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WriteFileBd
-- handle is a string
-- bd is a chilkat.BinData
-- ok is true, or nil and err on failure
local ok, err = sftp:write_file_bd(handle, bd)
Introduced in version 9.5.0.77

Appends all bytes in bd to the remote file identified by handle. The handle must have been returned by OpenFile.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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WriteFileText
-- handle is a string
-- charset is a string
-- text_data is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:write_file_text(handle, charset, text_data)

Encodes textData using charset and writes the resulting bytes at the current sequential write position for handle.

The position is maintained by Chilkat for the handle. Opening an existing file with openOrCreate positions sequential writes at the current end of the file. An explicit-offset write can change the position used by the next sequential write. When the file was opened with appendData, writes are forced to the end.

See Supported Charsets.

No byte-order mark or line ending is added unless it is present in the supplied text or produced by the selected encoding.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

More Information and Examples
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WriteFileText32
-- handle is a string
-- offset32 is an integer
-- charset is a string
-- text_data is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:write_file_text32(handle, offset32, charset, text_data)

Encodes textData using charset and writes the resulting bytes to handle at the 32-bit byte offset offset32.

After a successful explicit-offset write, the next sequential write begins immediately after the bytes written by this call. If the file was opened with appendData, the server appends and the explicit offset does not control placement.

See Supported Charsets.

offset32 must be nonnegative. A negative value can be interpreted as a very large unsigned offset. Writing beyond end-of-file can create a sparse file; whether the gap is sparse is determined by the server filesystem.
No byte-order mark or line ending is added unless it is present in the supplied text or produced by the selected encoding.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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WriteFileText64
-- handle is a string
-- offset64 is an integer
-- charset is a string
-- text_data is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:write_file_text64(handle, offset64, charset, text_data)

Encodes textData using charset and writes the resulting bytes to handle at the 64-bit byte offset offset64.

See Supported Charsets.

No byte-order mark or line ending is added unless it is present in the supplied text or produced by the selected encoding.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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WriteFileText64s
-- handle is a string
-- offset64 is a string
-- charset is a string
-- text_data is a string
-- ok is true, or nil and err on failure
local ok, err = sftp:write_file_text64s(handle, offset64, charset, text_data)

Encodes textData using charset and writes the resulting bytes to handle at the byte offset supplied as decimal string offset64.

See Supported Charsets.

No byte-order mark or line ending is added unless it is present in the supplied text or produced by the selected encoding.

Returns true on success, nil, err on failure. The second return value, err, is the object's last_error_text; wrap the call in assert() to raise an error instead.

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Events

All Chilkat methods are synchronous: the call returns when the work is done. During a long-running call, chilkat.SFtp reports progress to the functions given to set_event_handler, in a table keyed by event name (plain functions, not methods: closures carry whatever state they need):

sftp:set_event_handler({
    percent_done  = function(pct) print(pct .. "%") end,              -- return true to abort
    progress_info = function(name, value) print(name, value) end,
})
sftp.heartbeat_ms = 250   -- abort_check is called 4 times per second
sftp:set_event_handler({ event_name = function(...) ... end, ... })

Installs the handlers, replacing any installed before; sftp:set_event_handler(nil) removes them. The event names are checked when the table is installed: a misspelled one raises an error.

The abort_check handler is called at the interval set by the heartbeat_ms property (0, the default, disables it); percent_done is called when an operation's completion percentage is known; progress_info delivers named progress values. A true return from abort_check or percent_done aborts the running method, which then fails in the usual way (nil, err). An error raised in a handler aborts the method and is raised again from the method call; the object remains usable.

AbortCheck
-- handler: function() ... return abort end -- a true return aborts the method in progress
sftp:set_event_handler({ abort_check = function() ... end })

Enables a method call to be aborted by triggering the AbortCheck event at intervals defined by the HeartbeatMs property. If HeartbeatMs is set to its default value of 0, no events will occur. For instance, set HeartbeatMs to 200 to trigger 5 AbortCheck events per second.

More Information and Examples

Example

local deadline = os.time() + 30                  -- give up after 30 seconds
sftp.heartbeat_ms = 250                      -- call the handler 4 times per second
sftp:set_event_handler({ abort_check = function() return os.time() > deadline end })
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PercentDone
-- handler: function(pct_done) ... return abort end -- a true return aborts
sftp:set_event_handler({ percent_done = function(pct_done) ... end })

This provides the percentage completion for any method involving network communications or time-consuming processing, assuming the progress can be measured as a percentage. This event is triggered only when it's possible and logical to express the operation's progress as a percentage. The pctDone argument will range from 1 to 100. For methods that finish quickly, the number of PercentDone callbacks may vary, but the final callback will have pctDone equal to 100. For longer operations, callbacks will not exceed one per percentage point (e.g., 1, 2, 3, ..., 98, 99, 100).

The PercentDone callback also acts as an AbortCheck event. For fast methods where PercentDone fires, an AbortCheck event may not trigger since the PercentDone callback already provides an opportunity to abort. For longer operations, where time between PercentDone callbacks is extended, AbortCheck callbacks enable more responsive operation termination.

To abort the operation, set the abort output argument to true. This will cause the method to terminate and return a failure status or corresponding failure value.

More Information and Examples

Example

sftp:set_event_handler({
    percent_done = function(pct_done)     -- 0 to 100
        print("Percent done: " .. pct_done)
        return false                       -- return true to abort the method in progress
    end,
})
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ProgressInfo
-- handler: function(name, value) ... end
sftp:set_event_handler({ progress_info = function(name, value) ... end })

This event callback provides tag name/value pairs that detail what occurs during a method call. To discover existing tag names, create code to handle the event, emit the pairs, and review them. Most tag names are self-explanatory.

Note: Some Chilkat methods don't fire any ProgressInfo events.

More Information and Examples

Example

sftp:set_event_handler({
    progress_info = function(name, value) print(name .. ": " .. value) end,
})
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