curl/docs/cmdline-opts/write-out.md

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c: Copyright (C) Daniel Stenberg, daniel@haxx.se, et al. SPDX-License-Identifier: curl Long: write-out Short: w Arg: Help: Output FORMAT after completion Category: verbose Added: 6.5 Multi: single See-also:

• verbose
• head Example:
• -w '%{response_code}\n' $URL ---

--write-out

Make curl display information on stdout after a completed transfer. The format is a string that may contain plain text mixed with any number of variables. The format can be specified as a literal "string", or you can have curl read the format from a file with "@filename" and to tell curl to read the format from stdin you write "@-".

The variables present in the output format are substituted by the value or text that curl thinks fit, as described below. All variables are specified as %{variable_name} and to output a normal % you just write them as %%. You can output a newline by using \n, a carriage return with \r and a tab space with \t.

The output is by default written to standard output, but can be changed with %{stderr} and %output{}.

Output HTTP headers from the most recent request by using %header{name} where name is the case insensitive name of the header (without the trailing colon). The header contents are exactly as sent over the network, with leading and trailing whitespace trimmed (added in 7.84.0).

Select a specific target destination file to write the output to, by using %output{name} (added in curl 8.3.0) where name is the full filename. The output following that instruction is then written to that file. More than one %output{} instruction can be specified in the same write-out argument. If the filename cannot be created, curl leaves the output destination to the one used prior to the %output{} instruction. Use %output{>>name} to append data to an existing file.

This output is done independently of if the file transfer was successful or not.

If the specified action or output specified with this option fails in any way, it does not make curl return a (different) error.

NOTE: On Windows, the %-symbol is a special symbol used to expand environment variables. In batch files, all occurrences of % must be doubled when using this option to properly escape. If this option is used at the command prompt then the % cannot be escaped and unintended expansion is possible.

The variables available are:

certs

Output the certificate chain with details. Supported only by the OpenSSL, GnuTLS, Schannel and Secure Transport backends. (Added in 7.88.0)

conn_id

The connection identifier last used by the transfer. The connection id is unique number among all connections using the same connection cache. (Added in 8.2.0)

content_type

The Content-Type of the requested document, if there was any.

errormsg

The error message. (Added in 7.75.0)

exitcode

The numerical exit code of the transfer. (Added in 7.75.0)

filename_effective

The ultimate filename that curl writes out to. This is only meaningful if curl is told to write to a file with the --remote-name or --output option. It is most useful in combination with the --remote-header-name option. (Added in 7.26.0)

ftp_entry_path

The initial path curl ended up in when logging on to the remote FTP server. (Added in 7.15.4)

header_json

A JSON object with all HTTP response headers from the recent transfer. Values are provided as arrays, since in the case of multiple headers there can be multiple values. (Added in 7.83.0)

The header names provided in lowercase, listed in order of appearance over the wire. Except for duplicated headers. They are grouped on the first occurrence of that header, each value is presented in the JSON array.

http_code

The numerical response code that was found in the last retrieved HTTP(S) or FTP(s) transfer.

http_connect

The numerical code that was found in the last response (from a proxy) to a curl CONNECT request. (Added in 7.12.4)

http_version

The http version that was effectively used. (Added in 7.50.0)

json

A JSON object with all available keys. (Added in 7.70.0)

local_ip

The IP address of the local end of the most recently done connection - can be either IPv4 or IPv6. (Added in 7.29.0)

local_port

The local port number of the most recently done connection. (Added in 7.29.0)

method

The http method used in the most recent HTTP request. (Added in 7.72.0)

num_certs

Number of server certificates received in the TLS handshake. Supported only by the OpenSSL, GnuTLS, Schannel and Secure Transport backends. (Added in 7.88.0)

num_connects

Number of new connects made in the recent transfer. (Added in 7.12.3)

num_headers

The number of response headers in the most recent request (restarted at each redirect). Note that the status line IS NOT a header. (Added in 7.73.0)

num_redirects

Number of redirects that were followed in the request. (Added in 7.12.3)

num_retries

Number of retries actually performed when --retry has been used. (Added in 8.9.0)

onerror

The rest of the output is only shown if the transfer returned a non-zero error. (Added in 7.75.0)

proxy_ssl_verify_result

The result of the HTTPS proxy's SSL peer certificate verification that was requested. 0 means the verification was successful. (Added in 7.52.0)

proxy_used

Returns 1 if the previous transfer used a proxy, otherwise 0. Useful to for example determine if a NOPROXY pattern matched the hostname or not. (Added in 8.7.0)

redirect_url

When an HTTP request was made without --location to follow redirects (or when --max-redirs is met), this variable shows the actual URL a redirect would have gone to. (Added in 7.18.2)

referer

The Referer: header, if there was any. (Added in 7.76.0)

remote_ip

The remote IP address of the most recently done connection - can be either IPv4 or IPv6. (Added in 7.29.0)

remote_port

The remote port number of the most recently done connection. (Added in 7.29.0)

response_code

The numerical response code that was found in the last transfer (formerly known as "http_code"). (Added in 7.18.2)

scheme

The URL scheme (sometimes called protocol) that was effectively used. (Added in 7.52.0)

size_download

The total amount of bytes that were downloaded. This is the size of the body/data that was transferred, excluding headers.

size_header

The total amount of bytes of the downloaded headers.

size_request

The total amount of bytes that were sent in the HTTP request.

size_upload

The total amount of bytes that were uploaded. This is the size of the body/data that was transferred, excluding headers.

speed_download

The average download speed that curl measured for the complete download. Bytes per second.

speed_upload

The average upload speed that curl measured for the complete upload. Bytes per second.

ssl_verify_result

The result of the SSL peer certificate verification that was requested. 0 means the verification was successful. (Added in 7.19.0)

stderr

From this point on, the --write-out output is written to standard error. (Added in 7.63.0)

stdout

From this point on, the --write-out output is written to standard output. This is the default, but can be used to switch back after switching to stderr. (Added in 7.63.0)

time_appconnect

The time, in seconds, it took from the start until the SSL/SSH/etc connect/handshake to the remote host was completed. (Added in 7.19.0)

time_connect

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

time_namelookup

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

time_posttransfer

The time it took from the start until the last byte is sent by libcurl. In microseconds. (Added in 8.10.0)

time_pretransfer

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

time_redirect

The time, in seconds, it took for all redirection steps including name lookup, connect, pretransfer and transfer before the final transaction was started. time_redirect shows the complete execution time for multiple redirections. (Added in 7.12.3)

time_starttransfer

The time, in seconds, it took from the start until the first byte is received. This includes time_pretransfer and also the time the server needed to calculate the result.

time_total

The total time, in seconds, that the full operation lasted.

url

The URL that was fetched. (Added in 7.75.0)

url.scheme

The scheme part of the URL that was fetched. (Added in 8.1.0)

url.user

The user part of the URL that was fetched. (Added in 8.1.0)

url.password

The password part of the URL that was fetched. (Added in 8.1.0)

url.options

The options part of the URL that was fetched. (Added in 8.1.0)

url.host

The host part of the URL that was fetched. (Added in 8.1.0)

url.port

The port number of the URL that was fetched. If no port number was specified and the URL scheme is known, that scheme's default port number is shown. (Added in 8.1.0)

url.path

The path part of the URL that was fetched. (Added in 8.1.0)

url.query

The query part of the URL that was fetched. (Added in 8.1.0)

url.fragment

The fragment part of the URL that was fetched. (Added in 8.1.0)

url.zoneid

The zone id part of the URL that was fetched. (Added in 8.1.0)

urle.scheme

The scheme part of the effective (last) URL that was fetched. (Added in 8.1.0)

urle.user

The user part of the effective (last) URL that was fetched. (Added in 8.1.0)

urle.password

The password part of the effective (last) URL that was fetched. (Added in 8.1.0)

urle.options

The options part of the effective (last) URL that was fetched. (Added in 8.1.0)

urle.host

The host part of the effective (last) URL that was fetched. (Added in 8.1.0)

urle.port

The port number of the effective (last) URL that was fetched. If no port number was specified, but the URL scheme is known, that scheme's default port number is shown. (Added in 8.1.0)

urle.path

The path part of the effective (last) URL that was fetched. (Added in 8.1.0)

urle.query

The query part of the effective (last) URL that was fetched. (Added in 8.1.0)

urle.fragment

The fragment part of the effective (last) URL that was fetched. (Added in 8.1.0)

urle.zoneid

The zone id part of the effective (last) URL that was fetched. (Added in 8.1.0)

urlnum

The URL index number of this transfer, 0-indexed. Unglobbed URLs share the same index number as the origin globbed URL. (Added in 7.75.0)

url_effective

The URL that was fetched last. This is most meaningful if you have told curl to follow location: headers.

xfer_id

The numerical identifier of the last transfer done. -1 if no transfer has been started yet for the handle. The transfer id is unique among all transfers performed using the same connection cache. (Added in 8.2.0)