TclCurl

NAME

SYNOPSIS

curlHandle configure ?options?

curlHandle perform

curlHandle duhandle

curlHandle getinfo curlinfo_option

curlhandle cleanup

curlhandle reset

curl::transfer ?options?

curl::version

curl::escape url

curl::unescape url

curl::curlConfig option

curl::versioninfo option

curl::easystrerror errorCode

DESCRIPTION

curl::init

RETURN VALUE

curlHandle to use.  

curlHandle configure ?options?

configure is called to set the options for the transfer. Most operations in TclCurl have default actions, and by using the appropriate options you can make them behave differently (as documented). All options are set with the option followed by a parameter.

Notes: the options set with this procedure are valid for the forthcoming data transfers that are performed when you invoke perform

The options are not reset between transfers (except where noted), so if you want subsequent transfers with different options, you must change them between the transfers. You can optionally reset all options back to the internal default with curlHandle reset.

curlHandle is the return code from the curl::init call.

OPTIONS

Behaviour options

-verbose

Set the parameter to non-zero to get the library to display a lot of verbose information about its operations. Very useful for libcurl and/or protocol debugging and understanding.

You hardly ever want this set in production use, you will almost always want this when you debug/report problems. Another neat option for debugging is -debugproc

-header

A non-zero parameter tells the extension to include the headers in the body output. This is only relevant for protocols that actually have headers preceding the data (like HTTP).

-noprogress

A non-zero parameter tells the extension to turn on the built-in progress meter. Nowadays it is turn off by default.

-nosignal

A non zero parameter tells TclCurl not use any functions that install signal handlers or any functions that cause signals to be sent to the process. This option is mainly here to allow multi-threaded unix applications to still set/use all timeout options etc, without risking getting signals.

Callback options

-writeproc

Use it to set a Tcl procedure that will be invoked by TclCurl as soon as there is received data that needs to be saved. The procedure will receive a single parameter with the data to be saved.

NOTE: you will be passed as much data as possible in all invokes, but you cannot possibly make any assumptions. It may be nothing if the file is empty or it may be thousands of bytes.

-file

File in which the transfered data will be saved.

-readproc

Sets a Tcl procedure to be called by TclCurl as soon as it needs to read data in order to send it to the peer. The procedure has to take one parameter, which will contain the maximun numbers of bytes to read. It should return the actual number of bytes read, or '0' if you want to stop the transfer.

-infile

File from which the data will be transfered.

-progressproc

Name of the Tcl procedure that will invoked by TclCurl with a frequent interval during operation (roughly once per second), no matter if data is being transfered or not. Unknown/unused argument values passed to the callback will be set to zero (like if you only download data, the upload size will remain 0), the prototype of the procedure must be:

proc ProgressCallback {dltotal dlnow ultotal ulnow}

In order to this option to work you have to set the noprogress option to '0'. Setting this option to the empty string will restore the original progress function.

If you transfer data with the multi interface, this procedure will not be called during periods of idleness unless you call the appropriate procedure that performs transfers. Usage of the -progressproc callback is not recommended when using the multi interface.

-writeheader

Pass a the file name to be used to write the header part of the received data to. The headers are guaranteed to be written one-by-one to this file and only complete lines are written. Parsing headers should be easy enough using this.

-debugproc

Name of the procedure that will receive the debug data produced by the -verbose option, it should match the following prototype:

debugProc {infoType data}

where infoType specifies what kind of information it is (0 text, 1 incoming header, 2 outgoing header, 3 incoming data, 4 outgoing data, 5 incoming SSL data, 6 outgoing SSL data).

Error Options

-errorbuffer

Pass a variable name where TclCurl may store human readable error messages in. This may be more helpful than just the return code from the command.

-stderr

Pass a file name as parameter. This is the stream to use internally instead of stderr when reporting errors.

-failonerror

A non-zero parameter tells the extension to fail silently if the HTTP code returned is equal or larger than 400. The default action would be to return the page normally, ignoring that code.

This method is not fail-safe and there are occasions where non-succesful response codes will slip through, especially when authentication is involved (response codes 401 and 407).

You might get some amounts of headers transferred before this situation is detected, like for when a "100-continue" is received as a response to a POST/PUT and a 401 or 407 is received immediately afterwards.

Network options

-url

The actual URL to deal with.

If the given URL lacks the protocol part ("http://" or "ftp://" etc), it will attempt to guess which protocol to use based on the given host name. If the given protocol of the set URL is not supported, TclCurl will return the +(unsupported protocol) error when you call perform. Use curl::versioninfo for detailed info on which protocols that are supported.

NOTE: this the one option required to be set before perform is called.

-proxy

If you need to use a http proxy to access the outside world, set the proxy string with this option. To specify port number in this string, append :[port] to the end of the host name. The proxy string may be prefixed with [protocol]:// since any such prefix will be ignored.

When you tell the extension to use a HTTP proxy, TclCurl will transparently convert operations to HTTP even if you specify a FTP URL etc. This may have an impact on what other features of the library you can use, such as quote and similar FTP specifics that will not work unless you tunnel through the HTTP proxy. Such tunneling is activated with proxytunnel

TclCurl respects the environment variables http_proxy, ftp_proxy, all_proxy etc, if any of those are set. The use of this option does however override any possibly set environment variables.

The proxy host string can be specified the exact same way as the proxy environment variables, include protocol prefix (http://) and embedded user + password.

-proxyport

Use this option to set the proxy port to use unless it is specified in the proxy string by -proxy.

-proxytype

Pass the type of the proxy. Available options are 'http', "socks4" and

man2html: unable to open or read file

-httpproxytunnel

Set the parameter to non-zero to get the extension to tunnel all non-HTTP operations through the given HTTP proxy. Do note that there is a big difference between using a proxy and tunneling through it. If you don't know what this means, you probably don't want this tunnel option.

-interface

Pass the interface name to use as outgoing network interface. The name can be an interface name, an IP address or a host name.

-localport

This sets the local port number of the socket used for connection. This can be used in combination with -interface and you are recommended to use localportrange as well when this is set. Note the only valid port numbers are 1 - 65535.

-localportrange

This is the number of attempts TclCurl should do to find a working local port number. It starts with the given -localport and adds one to the number for each retry. Setting this value to 1 or below will make TclCurl do only one try for exact port number. Note that port numbers by nature are a scarce resource that will be busy at times so setting this value to something too low might cause unnecessary connection setup failures.

-dnscachetimeout

Pass the timeout in seconds. Name resolves will be kept in memory for this number of seconds. Set to '0' to completely disable caching, or '-1' to make the cached entries remain forever. By default, TclCurl caches this info for 60 seconds.

-dnsuseglobalcache

If the value passed is non-zero, it tells TclCurl to use a global DNS cache that will survive between curl handles creations and deletions. This is not thread-safe as it uses a global varible.

WARNING: this option is considered obsolete. Stop using it. Switch over to using the share interface instead! See tclcurl_share.

-buffersize

Pass your prefered size for the receive buffer in TclCurl. The main point of this would be that the write callback gets called more often and with smaller chunks. This is just treated as a request, not an order. You cannot be guaranteed to actually get the given size.

-port

Pass the number specifying what remote port to connect to, instead of the one specified in the URL or the default port for the used protocol.

-tcpnodelay

Pass a number to specify whether the TCP_NODELAY option should be set or cleared (1 = set, 0 = clear). The option is cleared by default. This will have no effect after the connection has been established.

Setting this option will disable TCP's Nagle algorithm. The purpose of this algorithm is to try to minimize the number of small packets on the network (where "small packets" means TCP segments less than the Maximum Segment Size (MSS) for the network).

Maximizing the amount of data sent per TCP segment is good because it amortizes the overhead of the send. However, in some cases (most notably telnet or rlogin) small segments may need to be sent without delay. This is less efficient than sending larger amounts of data at a time, and can contribute to congestion on the network if overdone.

Names and Passwords options

-netrc

A non-zero parameter tells the extension to scan your ~/.netrc file to find user name and password for the remote site you are about to access. Do note that TclCurl does not verify that the file has the correct properties set (as the standard unix ftp client does), and that only machine name, user name and password is taken into account (init macros and similar things are not supported).

You can set it to the following values:

optional

The use of your ~/.netrc file is optional, and information in the URL is to be preferred. The file will be scanned with the host and user name (to find the password only) or with the host only, to find the first user name and password after that machine, which ever information is not specified in the URL.

Undefined values of the option will have this effect.

ignored

The extension will ignore the file and use only the information in the URL. This is the default.

required

This value tells the library that use of the file is required, to ignore the information in the URL, and to search the file with the host only.

-netrcfile

Pass a string containing the full path name to the file you want to use as required. If this option is omitted, and netrc is set, TclCurl will attempt to find the a .netrc file in the current user's home directory.

-userpwd

Pass a string as parameter, which should be [username]:[password] to use for the connection. Use httpauth to decide authentication method.

When using NTLM, you can set domain by prepending it to the user name and separating the domain and name with a forward (/) or backward slash (\). Like this: "domain/user:password" or "domain\user:password". Some HTTP servers (on Windows) support this style even for Basic authentication.

When using HTTP and -followlocation, TclCurl might perform several requests to possibly different hosts. TclCurl will only send this user and password information to hosts using the initial host name (unless -unrestrictedauth is set), so if TclCurl follows locations to other hosts it will not send the user and password to those. This is enforced to prevent accidental information leakage.

-proxyuserpwd

Pass a string as parameter, which should be [username]:[password] to use for the connection to the HTTP proxy.

-httpauth

Set to the authentication method you want, the available ones are:

basic

HTTP Basic authentication. This is the default choice, and the only method that is in widespread use and supported virtually everywhere. It sends the user name and password over the network in plain text, easily captured by others.

digest

HTTP Digest authentication. Digest authentication is a more secure way to do authentication over public networks than the regular old-fashioned Basic method.

gssnegotiate

HTTP GSS-Negotiate authentication. The GSS-Negotiate method, also known as plain "Negotiate",was designed by Microsoft and is used in their web applications. It is primarily meant as a support for Kerberos5 authentication but may be also used along with another authentication methods.

ntlm

HTTP NTLM authentication. A proprietary protocol invented and used by Microsoft. It uses a challenge-response and hash concept similar to Digest, to prevent the password from being eavesdropped.

any

TclCurl will automatically select the one it finds most secure.

anysafe

It may use anything but basic, TclCurl will automaticly select the one it finds most secure.

-proxyauth

Use it to tell TclCurl which authentication method(s) you want it to use for your proxy authentication. Note that for some methods, this will induce an extra network round-trip. Set the actual name and password with the proxyuserpwd option.

The methods are those listed above for the httpauth option. As of this writing, only Basic and NTLM work.

HTTP options

-autoreferer

Pass a non-zero parameter to enable this. When enabled, TclCurl will automatically set the Referer: field in requests where it follows a Location: redirect.

-encoding

Sets the contents of the Accept-Encoding: header sent in an HTTP request, and enables decoding of a response when a Content-Encoding: header is received. Three encodings are supported: identity, which does nothing, deflate which requests the server to compress its response using the zlib algorithm, and gzip which requests the gzip algorithm. Use all to send an Accept-Encoding: header containing all supported encodings.

This is a request, not an order; the server may or may not do it. This option must be set or else any unsolicited encoding done by the server is ignored. See the special file lib/README.encoding in libcurl docs for details.

-followlocation

A non-zero parameter tells the library to follow any Location: header that the server sends as part of a HTTP header.

NOTE: this means that the extension will re-send the same request on the new location and follow new Location: headers all the way until no more such headers are returned. -maxredirs can be used to limit the number of redirects TclCurl will follow.

-unrestrictedauth

A non-zero parameter tells the extension it can continue to send authentication (user+password) when following locations, even when hostname changed. Note that this is meaningful only when setting -followlocation.

-maxredirs

Sets the redirection limit. If that many redirections have been followed, the next redirect will cause an error. This option only makes sense if the -followlocation option is used at the same time. Setting the limit to 0 will make libcurl refuse any redirect. Set it to -1 for an infinite number of redirects (which is the default)

-put

A non-zero parameter tells the extension to use HTTP PUT a file. The file to put must be set with -infile and -infilesize.

This option is deprecated starting with version 0.12.1, you should use -upload.

-post

A non-zero parameter tells the library to do a regular HTTP post. This is a normal application/x-www-form-urlencoded kind, which is the most commonly used one by HTML forms. See the -postfields option for how to specify the data to post and -postfieldsize about how to set the data size.

Use the -postfields option to specify what data to post and -postfieldsize to set the data size. Optionally, you can provide data to POST using the -readproc options.

You can override the default POST Content-Type: header by setting your own with -httpheader.

Using POST with HTTP 1.1 implies the use of a "Expect: 100-continue" header. You can disable this header with -httpheader as usual.

If you use POST to a HTTP 1.1 server, you can send data without knowing the size before starting the POST if you use chunked encoding. You enable this by adding a header like "Transfer-Encoding: chunked" with -httpheader. With HTTP 1.0 or without chunked transfer, you must specify the size in the request.

When setting post to a non-zero value, it will automatically set nobody to 0.

NOTE: if you have issued a POST request and want to make a HEAD or GET instead, you must explicitly pick the new request type using -nobody or -httpget or similar.

-postfields

Pass a string as parameter, which should be the full data to post in a HTTP POST operation. You must make sure that the data is formatted the way you want the server to receive it. TclCurl will not convert or encode it for you. Most web servers will assume this data to be url-encoded.

This is a normal application/x-www-form-urlencoded kind, which is the most commonly used one by HTML forms.

Note: to make multipart/formdata posts (aka rfc1867-posts), check out httppost option.

-postfieldsize

If you want to post data to the server without letting TclCurl do a strlen() to measure the data size, this option must be used. Also, when this option is used, you can post fully binary data which otherwise is likely to fail. If this size is set to zero, the library will use strlen() to get the data size.

-httppost

Tells TclCurl you want a multipart/formdata HTTP POST to be made and you instruct what data to pass on to the server through a Tcl list.

This is the only case where the data is reset after a transfer.

First, there are some basics you need to understand about multipart/formdata posts. Each part consists of at least a NAME and a CONTENTS part. If the part is made for file upload, there are also a stored CONTENT-TYPE and a FILENAME. Below, we'll discuss on what options you use to set these properties in the parts you want to add to your post.

The list must contain a 'name' tag with the name of the section followed by a string with the name, there are three tags to indicate the value of the section: 'value' followed by a string with the data to post, 'file' followed by the name of the file to post and 'contenttype' with the type of the data (text/plain, image/jpg, ...), you can also indicate a false file name with 'filename', this is useful in case the server checks if the given file name is valid, for example, by testing if it starts with 'c:\' as any real file name does or if you want to include the full path of the file to post. You can also post the content of a variable as if it were a file with the options 'bufferName' and 'buffer' or use 'filecontent' followed by a file name to read that file and use the contents as data.

Should you need to specify extra headers for the form POST section, use 'contentheader' followed by a list with the headers to post.

Please see 'httpPost.tcl' and 'httpBufferPost.tcl' for examples.

If TclCurl can't set the data to post an error will be returned:

1

If the memory allocation fails.

2

If one option is given twice for one form.

3

If an empty string was given.

4

If an unknown option was used.

5

If the some form info is not complete (or error)

6

If an illegal option is used in an array.

7

TclCurl has no http support.

-referer

Pass a string as parameter. It will be used to set the referer header in the http request sent to the remote server. This can be used to fool servers or scripts. You can also set any custom header with -httpheader.

-useragent

Pass a string as parameter. It will be used to set the user-agent: header in the http request sent to the remote server. This can be used to fool servers or scripts. You can also set any custom header with -httpheader.

-httpheader

Pass a list with the HTTP headers to pass to the server in your request. If you add a header that is otherwise generated and used by TclCurl internally, your added one will be used instead. If you add a header with no contents as in 'Accept:', the internally used header will just get disabled. Thus, using this option you can add new headers, replace and remove internal headers.

The headers included in the linked list must not be CRLF-terminated, because TclCurl adds CRLF after each header item. Failure to comply with this will result in strange bugs because the server will most likely ignore part of the headers you specified.

The first line in a request (containing the method, usually a GET or POST) is not a header and cannot be replaced using this option. Only the lines following the request-line are headers. Adding this method line in this list of headers will only cause your request to send an invalid header.

NOTE:The most commonly replaced headers have "shortcuts" in the options: cookie, useragent, and referer.

-http200aliases

Pass a list of aliases to be treated as valid HTTP 200 responses. Some servers respond with a custom header response line. For example, IceCast servers respond with "ICY 200 OK". By including this string in your list of aliases, the response will be treated as a valid HTTP header line such as "HTTP/1.0 200 OK".

NOTE:The alias itself is not parsed for any version strings. So if your alias is "MYHTTP/9.9", TclCurl will not treat the server as responding with HTTP version 9.9. Instead TclCurl will use the value set by option httpversion

-cookie

Pass a string as parameter. It will be used to set a cookie in the http request. The format of the string should be what the cookie should contain.

If you need to set mulitple cookies, you need to set them all using a single option and thus you need to concatenate them all in one single string. Set multiple cookies in one string like this: "name1=content1; name2=content2;" etc.

Using this option multiple times will only make the latest string override the previously ones.

-cookiefile

Pass a string as parameter. It should contain the name of your file holding cookie data. The cookie data may be in netscape cookie data format or just regular HTTP-style headers dumped to a file.

Given an empty or non-existing file, this option will enable cookies for this curl handle, making it understand and parse received cookies and then use matching cookies in future requests.

If you use this option multiple times, you add more files to read.

-cookiejar

Pass a file name in which TclCurl will dump all internally known cookies when curlHandle cleanup is called. If no cookies are known, no file will be created. Specify "-" to have the cookies written to stdout.

Using this option also enables cookies for this session, so if you, for example, follow a location it will make matching cookies get sent accordingly.

TclCurl will not and cannot report an error for this. Using 'verbose' will get a warning to display, but that is the only visible feedback you get about this possibly lethal situation.

-cookiesession

Pass a non-zero number to mark this as a new cookie "session". It will force TclCurl to ignore all cookies it is about to load that are "session cookies" from the previous session. By default, TclCurl always stores and loads all cookies, independent of whether they are session cookies are not. Session cookies are cookies without expiry date and they are meant to be alive and existing for this "session" only.

-cookielist

Pass a string with a cookie. The cookie can be either in Netscape / Mozilla format or just regular HTTP-style header (Set-Cookie: ...) format. If the cookie engine was not enabled it will be enabled. Passing a magic string "ALL" will erase all known cookies.

-httpget

If set to non-zero forces the HTTP request to get back to GET, usable if POST, PUT or a custom request have been used previously with the same handle.

When setting httpget to a non-zero value, nobody will automatically be set to 0.

-httpversion

Set to one of the values decribed below, they force TclCurl to use the specific http versions. It should only be used if you really MUST do that because of a silly remote server.

none

We do not care about what version the library uses. TclCurl will use whatever it thinks fit.

1.0

Enforce HTTP 1.0 requests.

1.1

Enforce HTTP 1.1 requests.

-ignorecontentlength

Ignore the Content-Length header. This is useful for Apache 1.x (and similar servers) which will report incorrect content length for files over 2 gigabytes. If this option is used, TclCurl will not be able to accurately report progress, and will simply stop the download when the server ends the connection.

FTP options

-ftpport

Pass a string as parameter. It will be used to get the IP address to use for the ftp PORT instruction. The PORT instruction tells the remote server to connect to our specified IP address. The string may be a plain IP address, a host name, a network interface name (under unix) or just a '-' to let the library use your systems default IP address. Default FTP operations are passive, and thus will not use PORT.

-quote

Pass a list list with the FTP commands to pass to the server prior to your ftp request. This will be done before any other FTP commands are issued (even before the CWD command).If you do not want to transfer any files, set nobody to '1' and header to '0'.

Keep in mind the commands to send must be 'raw' ftp commands, for example, to create a directory you need to send mkd Test, not mkdir Test.

-postquote

Pass a list with the FTP commands to pass to the server after your ftp transfer request. If you do not want to transfer any files, set nobody to '1' and header to '0'.

-prequote

Pass a list of FTP commands to pass to the server after the transfer type is set.

-ftplistonly

A non-zero parameter tells the library to just list the names of a ftp directory, instead of doing a full directory listing that would include file sizes, dates etc.

This causes an FTP NLST command to be sent. Beware that some FTP servers list only files in their response to NLST they might not include subdirectories and symbolic links.

-ftpappend

A non-zero parameter tells the extension to append to the remote file instead of overwriting it. This is only useful when uploading to a ftp site.

-ftpuseeprt

Set to non-zero, to tell TclCurl to use the EPRT (and LPRT) command when doing active FTP downloads (which is enabled by 'ftpport'). Using EPRT means that it will first attempt to use EPRT and then LPRT before using PORT, if you pass zero to this option, it will not try using EPRT or LPRT, only plain PORT.

-ftpuseepvs

Set to one to tell TclCurl to use the EPSV command when doing passive FTP downloads (which it always does by default). Using EPSV means that it will first attempt to use EPSV before using PASV, but if you pass a zero to this option, it will not try using EPSV, only plain PASV.

-ftpcreatemissingdirs

If set to non-zero, TclCurl will attempt to create any remote directory that it fails to CWD into. CWD is the command that changes working directory.

-ftpresponsetimeout

Causes TclCurl to set a timeout period (in seconds) on the amount of time that the server is allowed to take in order to generate a response message for a command before the session is considered hung. Note that while TclCurl is waiting for a response, this value overrides timeout. It is recommended that if used in conjunction with timeout, you set it to a value smaller than timeout.

:TP -ftpalternativetoiser Pass a string which will be used to authenticate if the usual FTP "USER user" and "PASS password" negotiation fails. This is currently only known to be required when connecting to Tumbleweed's Secure Transport FTPS server using client certificates for authentication.

-ftpskippasvip

If set to a non-zero value, it instructs TclCurl not to use the IP address the server suggests in its 227-response to TclCurl's PASV command when TclCurl connects the data connection. Instead TclCurl will re-use the same IP address it already uses for the control connection. But it will use the port number from the 227-response.

This option has no effect if PORT, EPRT or EPSV is used instead of PASV.

-ftpssl

You can use ftps:// URLs to explicitly switch on SSL/TSL for the control connection and the data connection.

Alternatively, and what seems to be the recommended way, you can set the option to one of these values:

nope

Do not attempt to use SSL

try

Try using SSL, proceed anyway otherwise.

control

Use SSL for the control conecction or fail with "ftp ssl failed" (64).

all

Use SSL for all communication or fail with "ftp ssl failed" (64).

-ftpsslauth

Pass TclCurl one of the values from below, to alter how TclCurl issues "AUTH TLS" or "AUTH SSL" when FTP over SSL is activated (see -ftpssl).

You may need this option because of servers like BSDFTPD-SSL which won't work properly when "AUTH SSL" is issued (although the server responds fine and everything) but requires "AUTH TLS" instead".

default

Allows TclCurl to decide.

ssl

Try "AUTH SSL" first, and only if that fails try "AUTH TLS".

tls

Try "AUTH TLS" first, and only if that fails try "AUTH SSL".

-sourceprequote

Pass a list of FTP commands to issue to the source host just before the transfer command (RETR or STOR etc).

-sourcepostquote

Pass a list with the FTP commands to pass to the source server after your ftp transfer request.

-ftpaccount

Pass string (or "" to disable). When an FTP server asks for "account data" after user name and password has been provided, this data is sent off using the ACCT command.

-ftpfilemethod

It allows three values:

multicwd

The default, TclCurl will do a single CWD operation for each path part in the given URL. For deep hierarchies this means very many commands. This is how RFC1738 says it should be done.

nocwd

No CWD at all is done, TclCurl will do SIZE, RETR, STOR, etc and give a full path to the server.

singlecwd

Make one CWD with the full target directory and then operate on the file "normally".

The support for this options is still experimental, comments whether the methods work or do not with different servers are welcome.

Protocol options

-transfertext

A non-zero parameter tells the extension to use ASCII mode for ftp transfers, instead of the default binary transfer. For win32 systems it does not set the stdout to binary mode. This option can be usable when transferring text data between systems with different views on certain characters, such as newlines or similar.

NOTE: TclCurl does not do a complete ASCII conversion when doing ASCII transfers over FTP. This is a known limitation/flaw that nobody has rectified. TclCurl simply sets the mode to ascii and performs a standard transfer.

-crlf

Convert unix newlines to CRLF newlines on FTP transfers.

-range

Pass a string as parameter, which should contain the specified range you want. It should be in the format X-Y , where X or Y may be left out. HTTP transfers also support several intervals, separated with commas as in X-Y,N-M Using this kind of multiple intervals will cause the HTTP server to send the response document in pieces.

-resumefrom

Pass the offset in number of bytes that you want the transfer to start from. Set this option to 0 to make the transfer start from the beginning (effectively disabling resume).

For FTP, set this option to -1 to make the transfer start from the end of the target file (useful to continue an interrupted upload).

-customrequest

Pass a string as parameter. It will be used instead of GET or HEAD when doing the HTTP request. This is useful for doing DELETE or other more obscure HTTP requests. Do not do this at will, make sure your server supports the command first.

-filetime

If you pass a non-zero value, TclCurl will attempt to get the modification date of the remote document in this operation. This requires that the remote server sends the time or replies to a time querying command. The getinfo procedure with the filetime argument can be used after a transfer to extract the received time (if any).

-nobody

A non-zero parameter tells the library not to include the body-part in the output. This is only relevant for protocols that have a separate header and body part. On HTTP(S) servers, this will make TclCurl do a HEAD request.

To change request to GET, you should use httpget. Change request to POST with post etc.

-infilesize

When uploading a file to a remote site, this option should be used to tell TclCurl what the expected size of the infile is.

-upload

A non-zero parameter tells the library to prepare for an upload. The -infile and -infilesize options are also interesting for uploads. If the protocol is HTTP, uploading means using the PUT request unless you tell TclCurl otherwise.

Using PUT with HTTP 1.1 implies the use of a "Expect: 100-continue" header. You can disable this header with -httpheader as usual.

If you use PUT to a HTTP 1.1 server, you can upload data without knowing the size before starting the transfer if you use chunked encoding. You enable this by adding a header like "Transfer-Encoding: chunked" with-httpheader. With HTTP 1.0 or without chunked transfer, you must specify the size.

-maxfilesize

This allows you to specify the maximum size (in bytes) of a file to download. If the file requested is larger than this value, the transfer will not start and error 'filesize exceeded' (63) will be returned.

NOTE: The file size is not always known prior to download, and for such files this option has no effect even if the file transfer ends up being larger than this given limit. This concerns both FTP and HTTP transfers.

-timecondition

This defines how the timevalue value is treated. You can set this parameter to ifmodsince or ifunmodsince. This feature applies to HTTP and FTP.

-timevalue

This should be the time in seconds since 1 jan 1970, and the time will be used in a condition as specified with timecondition.

Connection options

-timeout

Pass the maximum time in seconds that you allow the TclCurl transfer operation to take. Do note that normally, name lookups may take a considerable time and that limiting the operation to less than a few minutes risks aborting perfectly normal operations. This option will cause libcurl to use the SIGALRM to enable time-outing system calls.

In unix-like systems, this might cause signals to be used unless -nosignal is used.

-lowspeedlimit

Pass the speed in bytes per second that the transfer should be below during lowspeedtime seconds for the extension to consider it too slow and abort.

-lowspeedtime

Pass the time in seconds that the transfer should be below the lowspeedlimit for the extension to consider it too slow and abort.

-maxsendspeed

Pass a speed in bytes per seconds. If an upload exceeds this speed on cumulative average during the transfer, the transfer will pause to keep the average rate less than or equal to the parameter value. Defaults to unlimited speed.

-maxrecvspeed

Pass a speed in bytes per second. If a download exceeds this speed on cumulative average during the transfer, the transfer will pause to keep the average rate less than or equal to the parameter value. Defaults to unlimited speed.

-maxconnects

Sets the persistant connection cache size. The set amount will be the maximum amount of simultaneous connections that TclCurl may cache between file transfers. Default is 5, and there is not much point in changing this value unless you are perfectly aware of how this works and changes the behaviour of TclCurl.

When reaching the maximum limit, TclCurl uses the closepolicy to figure out which of the existing connections to close to prevent the number of open connections to increase.

Note: if you have already performed transfers with this curl handle, setting a smaller maxconnects than before may cause open connections to unnecessarily get closed.

-closepolicy

This option sets what policy TclCurl should use when the connection cache is filled and one of the open connections has to be closed to make room for a new connection. Use leastrecentlyused to make libcurl close the connection that was least recently used, that connection is also least likely to be capable of reuse. Use oldest to make libcurl close the oldest connection, the one that was created first among the ones in the connection cache.

-connecttimeout

Maximum time in seconds that you allow the connection to the server to take. This only limits the connection phase, once it has connected, this option is of no more use. Set to zero to disable connection timeout (it will then only timeout on the internal timeouts).

In unix-like systems, this might cause signals to be used unless -nosignal is set.

-ipresolve

Allows an application to select what kind of IP addresses to use when resolving host names. This is only interesting when using host names that resolve addresses using more than one version of IP. The allowed values are:

whatever

Default, resolves addresses to all IP versions that your system allows.

v4

Resolve to ipv4 addresses.

v6

Resolve to ipv6 addresses.

SSL and security options

-sslcert

Pass a string as parameter. The string should be the file name of your certificate. The default format is "PEM" and can be changed with -sslcerttype.

-sslcerttype

Pass a string as parameter. The string should be the format of your certificate. Supported formats are "PEM" and "DER".

-sslcertpasswd

Pass a string as parameter. It will be used as the password required to use the -sslcert certificate

NOTE:This option is replaced by -sslkeypasswd and only kept for backward compatibility. You never need a pass phrase to load a certificate but you need one to load your private key.

-sslkey

Pass a pointer to a zero terminated string as parameter. The string should be the file name of your private key. The default format is "PEM" and can be changed with -sslkeytype.

-sslkeytype

Pass a pointer to a zero terminated string as parameter. The string should be the format of your private key. Supported formats are "PEM", "DER" and "ENG"

NOTE:The format "ENG" enables you to load the private key from a crypto engine. in this case -sslkey is used as an identifier passed to the engine. You have to set the crypto engine with -sslengine. The "DER" format key file currently does not work because of a bug in OpenSSL.

-sslkeypasswd

Pass a string as parameter. It will be used as the password required to use the -sslkey private key.

-sslengine

Pass a string as parameter. It will be used as the identifier for the crypto engine you want to use for your private key.

NOTE:If the crypto device cannot be loaded, an error will be returned.

-sslenginedefault

Sets the actual crypto engine as the default for (asymmetric) crypto operations.

NOTE:If the crypto device cannot be set, an error will be returned.

-sslversion

Use it to set what version of SSL/TLS to use. The available options are:

default

The default action. When libcurl built with OpenSSL, this will attempt to figure out the remote SSL protocol version. Unfortunately there are a lot of ancient and broken servers in use which cannot handle this technique and will fail to connect. When libcurl is built with GnuTLS, this will mean SSLv3.

tlsv1

Force TLSv1

sslv2

Force SSLv2

sslv3

Force SSLv3

-sslverifypeer

This option determines whether TclCurl verifies the authenticity of the peer's certificate. A nonzero value means it verifies; zero means it doesn't. The default is nonzero.

When negotiating an SSL connection, the server sends a certificate indicating its identity. TclCurl verifies whether the certificate is authentic, i.e. that you can trust that the server is who the certificate says it is. This trust is based on a chain of digital signatures, rooted in certification authority (CA) certificates you supply.

TclCurl uses a default bundle of CA certificates that comes with libcurl but you can specify alternate certificates with the -cainfo or the -capath options.

When -sslverifypeer is nonzero, and the verification fails to prove that the certificate is authentic, the connection fails. When the option is zero, the connection succeeds regardless.

Authenticating the certificate is not by itself very useful. You typically want to ensure that the server, as authentically identified by its certificate, is the server you mean to be talking to, use -sslverifyhost to control that.

-cainfo

Pass a file naming holding the certificate to verify the peer with. This only makes sense when used in combination with the -sslverifypeer option, if it is set to zero -cainfo need not even indicate an accessible file.

-capath

Pass the directory holding multiple CA certificates to verify the peer with. The certificate directory must be prepared using the openssl c_rehash utility. This only makes sense when used in combination with the -sslverifypeer option, if it is set to zero, -capath need not even indicate an accessible path.

This option apparently does not work in Windows due to some limitation in openssl.

-randomfile

Pass a file name. The file will be used to read from to seed the random engine for SSL. The more random the specified file is, the more secure will the SSL connection become.

-egdsocket

Pass a path name to the Entropy Gathering Daemon socket. It will be used to seed the random engine for SSL.

-sslverifyhost

This option determines whether TclCurl verifies that the server claims to be who you want it to be.

When negotiating an SSL connection, the server sends a certificate indicating its identity.

When -sslverifyhost is set to 2, that certificate must indicate that the server is the server to which you meant to connect, or the connection fails.

TclCurl considers the server the intended one when the Common Name field or a Subject Alternate Name field in the certificate matches the host name in the URL to which you told Curl to connect.

When set to 1, the certificate must contain a Common Name field, but it does not matter what name it says. (This is not ordinarily a useful setting).

When the value is 0, the connection succeeds regardless of the names in the certificate.

The default is 2.

This option controls the identity that the server claims. The server could be lying. To control lying, see sslverifypeer.

-sslcypherlist

Pass a string holding the ciphers to use for the SSL connection. The list must consists of one or more cipher strings separated by colons. Commas or spaces are also acceptable separators but colons are normally used, , - and + can be used as operators. Valid examples of cipher lists include 'RC4-SHA', 'SHA1+DES',

You will find more details about cipher lists here.

-sslsessionidcache

Pass a 0 to disable TclCurl's use of SSL session-ID caching or a 1 to enable it. By default all transfers are done using the cache. Note that while nothing ever should get hurt by attempting to reuse SSL session-IDs, there seem to be broken SSL implementations in the wild that may require you to disable this in order for you to succeed.

-krb4level

Set the krb4 security level, this also enables krb4 awareness. This is a string, 'clear', 'safe', 'confidential' or 'private'. If the string is set but does not match one of these, 'private' will be used. Set the string to NULL to disable kerberos4. The kerberos support only works for FTP.

Other options

-headervar

Name of the Tcl array variable where TclCurl will store the headers returned by the server.

When a server sends a chunked encoded transfer, it may contain a trailer. That trailer is identical to a HTTP header and if such a trailer is received it is passed to the application using this callback as well. There are several ways to detect it being a trailer and not an ordinary header: 1) it comes after the response-body. 2) it comes after the final header line (CR LF) 3) a Trailer: header among the response-headers mention what header to expect in the trailer.

-bodyvar

Name of the Tcl variable where TclCurl will store the file requested, the file may contain text or binary data.

-canceltransvar

Name of a Tcl variable, in case you have defined a procedure to call with -progressproc setting this variable to '1' will cancel the transfer.

-command

Executes the given command after the transfer is done, since it only works with blocking transfers, it is pretty much useless.

-share

Pass a share handle as a parameter. The share handle must have been created by a previous call to curl::shareinit. Setting this option, will make this handle use the data from the shared handle instead of keeping the data to itself. See tclcurl_share for details.

NOT SUPPORTED

CURLOPT_FRESH_CONNECT, CURLOPT_FORBID_REUSE, CURLOPT_PRIVATE, CURLOPT_SSL_CTX_FUNCTION, CURLOPT_SSL_CTX_DATA, CURLOPT_SSL_CTX_FUNCTION and CURLOPT_CONNECT_ONLY.

curlHandle perform

It must be called with the same curlHandle curl::init call returned. You can do any amount of calls to perform while using the same handle. If you intend to transfer more than one file, you are even encouraged to do so. TclCurl will then attempt to re-use the same connection for the following transfers, thus making the operations faster, less CPU intense and using less network resources. Just note that you will have to use configure between the invokes to set options for the following perform.

You must never call this procedure simultaneously from two places using the same handle. Let it return first before invoking it another time. If you want parallel transfers, you must use several curl handles.

RETURN VALUE

errorbuffer was set with configure there will be a readable error message. The error codes are:

1

Unsupported protocol. This build of TclCurl has no support for this protocol.

2

Very early initialization code failed. This is likely to be and internal error or problem.

3

URL malformat. The syntax was not correct.

4

URL user malformatted. The user-part of the URL syntax was not correct. This error is no longer returned.

5

Couldn't resolve proxy. The given proxy host could not be resolved.

6

Couldn't resolve host. The given remote host was not resolved.

7

Failed to connect to host or proxy.

8

FTP weird server reply. The server sent data TclCurl couldn't parse. The given remote server is probably not an OK FTP server.

9

We were denied access when trying to login to a FTP server or when trying to change working directory to the one given in the URL.

10

FTP user/password incorrect. It might be because the username and/or the password were incorrect or just that the server is not allowing you access for the moment. This error is no longer returned.

11

FTP weird PASS reply. TclCurl couldn't parse the reply sent to the PASS request.

12

FTP weird USER reply. TclCurl couldn't parse the reply sent to the USER request.

13

FTP weird PASV reply, TclCurl couldn't parse the reply sent to the PASV request.

14

FTP weird 227 format. TclCurl couldn't parse the 227-line the server sent.

15

FTP can't get host. Couldn't resolve the host IP we got in the 227-line.

16

FTP can't reconnect. A bad return code on either PASV or EPSV was sent by the FTP server, preventing TclCurl from being able to continue.

17

FTP couldn't set binary. Couldn't change transfer method to binary.

18

Partial file. Only a part of the file was transfered, this happens when the server first reports an expected transfer size and then delivers data that doesn't match the given size.

19

FTP couldn't RETR file, we either got a weird reply to a 'RETR' command or a zero byte transfer.

20

FTP write error. After a completed file transferm the FTP server did not respond properly.

21

FTP quote error. A custom 'QUOTE' returned error code 400 or higher from the server.

22

HTTP not found. The requested page was not found. This return code only appears if --fail is used and the HTTP server returns an error code that is 400 or higher.

23

Write error. TclCurl couldn't write data to a local filesystem or an error was returned from a write callback.

24

Malformed user. User name badly specified. This error is no longer returned.

25

FTP couldn't STOR file. The server denied the STOR operation, the error buffer will usually have the server explanation, used for FTP uploading.

26

Read error. There was a problem reading from a local file or an error was returned from the read callback.

27

Out of memory. A memory allocation request failed. This should never happen unless something weird is going on in your computer.

28

Operation timeout. The specified time-out period was reached according to the conditions.

29

FTP couldn't set ASCII. The server returned an unknown reply.

30

The FTP PORT command failed, not all FTP servers support the PORT command, try doing a transfer using PASV instead!.

31

FTP couldn't use REST. This command is used for resumed FTP transfers.

32

FTP couldn't use the SIZE command. The command is an extension to the original FTP spec RFC 959, so not all servers support it.

33

HTTP range error. The server doesn't support or accept range requests.

34

HTTP post error. Internal post-request generation error.

35

SSL connect error. The SSL handshaking failed, the error buffer may have a clue to the reason, could be certificates, passwords, ...

36

FTP bad download resume. Couldn't continue an earlier aborted download, probably because you are trying to resume beyond the file size.

37

A file given with FILE:// couldn't be read. Did you checked the permissions?

38

LDAP cannot bind. LDAP bind operation failed.

39

LDAP search failed.

40

Library not found. The LDAP library was not found.

41

A required LDAP function was not found.

42

Aborted by callback. An application told TclCurl to abort the operation.

43

Internal error. A function was called with a bad parameter.

44

Internal error. A function was called in a bad order. This error is no longer returned.

45

Interface error. A specified outgoing interface could not be used.

46

Bad password entered. An error was signalled when the password was entered. This error is no longer returned.

47

Too many redirects. When following redirects, TclCurl hit the maximum amount, set your limit with --maxredirs

48

Unknown TELNET option specified.

49

A telnet option string was illegally formatted.

50

Currently not used.

51

The remote peer's SSL certificate wasn't ok

52

The server didn't reply anything, which here is considered an error.

53

The specified crypto engine wasn't found.

54

Failed setting the selected SSL crypto engine as default!

55

Failed sending network data.

56

Failure with receiving network data.

57

Share is in use (internal error).

58

Problem with the local client certificate.

59

Couldn't use specified SSL cipher.

60

Peer certificate cannot be authenticated with known CA certificates.

61

Unrecognized transfer encoding.

62

Invalid LDAP URL.

63

Maximum file size exceeded.

64

FTP SSL failed.

65

Sending the data requires a rewind that failed, since TclCurl should take care of it for you, it means you found a bug.

66

Failed to initialise ssl engine.

67

Failed to login, user password or similar was not accepted.

68

File not found on TFTP server.

69

There is a permission problem with the request.

70

The TFTP server has run out of space.

71

Illegal TFTP operation.

72

Unknown transfer ID.

73

TFTP file already exists.

74

No such user in the TFTP server.

75

Character conversion failed.

77

Problem with reading the SSL CA cert (path? access rights?).

curlHandle getinfo option

The following information can be extracted:

effectiveurl

Returns the last used effective URL.

responsecode

Returns the last received HTTP or FTP code. This will be zero if no server response code has been received. Note that a proxy's CONNECT response should be read with httpconnectcode and not this.

httpconnectcode

Returns the last received proxy response code to a CONNECT request.

filetime

Returns the remote time of the retrieved document (in number of seconds since 1 jan 1970 in the GMT/UTC time zone). If you get -1, it can be because of many reasons (unknown, the server hides it or the server doesn't support the command that tells document time etc) and the time of the document is unknown.

In order for this to work you have to set the -filetime option before the transfer.

namelookuptime

Returns the time, in seconds, it took from the start until the name resolving was completed.

connecttime

Returns the time, in seconds, it took from the start until the connect to the remote host (or proxy) was completed.

pretransfertime

Returns the time, in seconds, it took from the start until the file transfer is just about to begin. This includes all pre-transfer commands and negotiations that are specific to the particular protocol(s) involved.

starttransfertime

Returns the time, in seconds, it took from the start until the first byte is just about to be transfered. This includes the pretransfertime, and also the time the server needs to calculate the result.

totaltime

Returns the total transaction time, in seconds, for the previous transfer, including name resolving, TCP connect etc.

redirecttime

Returns the total time, in seconds, it took for all redirection steps including name lookup, connect, pretransfer and transfer before the final transaction was started, it returns the complete execution time for multiple redirections, so it returns zero if no redirections were needed.

redirectcount

Returns the total number of redirections that were actually followed.

numconnects

Returns how many new connections TclCurl had to create to achieve the previous transfer (only the successful connects are counted). Combined with redirectcount you are able to know how many times TclCurl successfully reused existing connection(s) or not. See the Connection Options of setopt to see how TclCurl tries to make persistent connections to save time.

sizeupload

Returns the total amount of bytes that were uploaded.

sizedownload

Returns the total amount of bytes that were downloaded. The amount is only for the latest transfer and will be reset again for each new transfer.

speeddownload

Returns the average download speed that curl measured for the complete download.

speedupload

Returns the average upload speed that curl measured for the complete upload.

headersize

Returns the total size of all the headers received.

requestsize

Returns the total size of the issued requests. This is so far only for HTTP requests. Note that this may be more than one request if followLocation is true.

sslverifyresult

Returns the result of the certification verification that was requested (using the -sslverifypeer option to configure).

sslengines

Returns a list of the OpenSSL crypto-engines supported. Note that engines are normally implemented in separate dynamic libraries. Hence not all the returned engines may be available at run-time.

contentlengthdownload

Returns the content-length of the download. This is the value read from the Content-Length: field.

contentlengthupload

Returns the specified size of the upload.

contenttype

Returns the content-type of the downloaded object. This is the value read from the Content-Type: field. If you get an empty string, it means the server didn't send a valid Content-Type header or that the protocol used doesn't support this.

httpauthavail

Returns a list with the authentication method(s) available.

proxyauthavail

Returns a list with the authentication method(s) available for your proxy athentication.

oserrno

Returns the errno value from a connect failure.

cookielist

Returns a list of all cookies TclCurl knows (expired ones, too). If there are no cookies (cookies for the handle have not been enabled or simply none have been received) the list will be empty.

ftpentrypath

Returns a string holding the path of the entry path. That is the initial path TclCurl ended up in when logging on to the remote FTP server. Returns an empty string if something is wrong.

curlHandle duphandle

RETURN VALUE

A new curl handle or an error message if the copy fails.

curlHandle cleanup

curlHandle reset

Re-initializes all options previously set on a specified handle to the default values.

This puts back the handle to the same state as it was in when it was just created with curl::init.

It does not change the following information kept in the handle: live connections, the Session ID cache, the DNS cache, the cookies and shares.

curl::transfer

You can also get the getinfo information by using -infooption variable pairs, after the transfer variable will contain the value that would have been returned by $curlHandle getinfo option.

RETURN VALUE

The same error code perform would return.

curl::version

RETURN VALUE

The string with the version info.

curl::escape url

RETURN VALUE

The converted string.

curl::unescape url

RETURN VALUE

The string unencoded.

curl::curlConfig option

-prefix

Returns the directory root where you installed cURL

-feature

Returns a list containing particular main features the installed libcurl was built with. The list may include SSL, KRB4 or IPv6, do not assume any particular order.

-vernum

Outputs version information about the installed libcurl, in numerical mode. This outputs the version number, in hexadecimal, with 8 bits for each part; major, minor, patch. So that libcurl 7.7.4 would appear as 070704 and libcurl 12.13.14 would appear as 0c0d0e...

curl::versioninfo option

Applications should use this information to judge if things are possible to do or not, instead of using compile-time checks, as dynamic/DLL libraries can be changed independent of applications.

-version

Returns the version of libcurl we are using.

-versionnum

Retuns the version of libcurl we are using in hexadecimal with 8 bits for each part; major, minor, patch. So that libcurl 7.7.4 would appear as 070704 and libcurl 12.13.14 would appear as 0c0d0e... Note that the initial zero might be omitted.

-host

Returns a string with the host information as discovered by a configure script or set by the build environment.

-features

Returns a list with the features compiled into libcurl, the possible elements are: IPV6, KERBEROS4, SSL, LIBZ, NTLM, GSSNEGOTIATE, DEBUG, ASYNCHDNS, , SPNEGO, LARGEFILE, IDN and SSPI. Do not assume any particular order.

-sslversion

Returns a string with the OpenSSL version used, like OpenSSL/0.9.6b.

-sslversionnum

Returns the numerical OpenSSL version value as defined by the OpenSSL project. If libcurl has no SSL support, this is 0.

-libzversion

Returns a string, there is no numerical version, for example: 1.1.3.

-protocols

Lists what particular protocols the installed TclCurl was built to support. At the time of writing, this list may include HTTP, HTTPS, FTP, FTPS, FILE, TELNET, LDAP, DICT. Do not assume any particular order. The protocols will be listed using uppercase. There may be none, one or several protocols in the list.

curl::easystrerror errorCode

SEE ALSO

Index

NAME

SYNOPSIS

DESCRIPTION

curl::init

curlHandle configure ?options?

Behaviour options

Callback options

Error Options

Network options

Names and Passwords options

HTTP options

FTP options

Protocol options

Connection options

SSL and security options

Other options

NOT SUPPORTED

curlHandle perform

curlHandle getinfo option

curlHandle duphandle

curlHandle cleanup

curlHandle reset

curl::transfer

curl::version

curl::escape url

curl::unescape url

curl::curlConfig option

curl::versioninfo option

curl::easystrerror errorCode

SEE ALSO