1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Long: variable 5Arg: <[%]name=text/@file> 6Help: Set variable 7Category: curl 8Added: 8.3.0 9Multi: append 10See-also: 11 - config 12Example: 13 - --variable name=smith --expand-url "$URL/{{name}}" 14--- 15 16# `--variable` 17 18Set a variable with `name=content` or `name@file` (where `file` can be stdin 19if set to a single dash (`-`)). The name is a case sensitive identifier that 20must consist of no other letters than a-z, A-Z, 0-9 or underscore. The 21specified content is then associated with this identifier. 22 23Setting the same variable name again overwrites the old contents with the new. 24 25The contents of a variable can be referenced in a later command line option 26when that option name is prefixed with `--expand-`, and the name is used as 27`{{name}}`. 28 29--variable can import environment variables into the name space. Opt to either 30require the environment variable to be set or provide a default value for the 31variable in case it is not already set. 32 33--variable %name imports the variable called `name` but exits with an error if 34that environment variable is not already set. To provide a default value if 35the environment variable is not set, use --variable %name=content or 36--variable %name@content. Note that on some systems - but not all - 37environment variables are case insensitive. 38 39When expanding variables, curl supports a set of functions that can make the 40variable contents more convenient to use. You apply a function to a variable 41expansion by adding a colon and then list the desired functions in a 42comma-separated list that is evaluated in a left-to-right order. Variable 43content holding null bytes that are not encoded when expanded, causes an 44error. 45 46Available functions: 47 48## trim 49removes all leading and trailing white space. 50 51## json 52outputs the content using JSON string quoting rules. 53 54## url 55shows the content URL (percent) encoded. 56 57## b64 58expands the variable base64 encoded 59
