3.4 KiB
| c | SPDX-License-Identifier | Long | Arg | Help | Category | Added | Multi | See-also | Example | ||
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| Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. | curl | variable | <[%]name=text/@file> | Set variable | curl | 8.3.0 | append |
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--variable
Set a variable with name=content or name@file (where file can be stdin
if set to a single dash (-)). The name is a case sensitive identifier that
must consist of no other letters than a-z, A-Z, 0-9 or underscore. The
specified content is then associated with this identifier.
Setting the same variable name again overwrites the old contents with the new.
The contents of a variable can be referenced in a later command line option
when that option name is prefixed with --expand-, and the name is used as
{{name}}.
--variable can import environment variables into the name space. Opt to either require the environment variable to be set or provide a default value for the variable in case it is not already set.
--variable %name imports the variable called name but exits with an error if
that environment variable is not already set. To provide a default value if
the environment variable is not set, use --variable %name=content or
--variable %name@content. Note that on some systems - but not all -
environment variables are case insensitive.
Added in curl 8.12.0: you can get a byte range from the source by appending
[start-end] to the variable name, where start and end are byte offsets
to include from the contents. For example, asking for offset "2-10" means
offset two to offset ten, inclusive, resulting in 9 bytes in total. 2-2
means a single byte at offset 2. Not providing a second number implies to the
end of data. The start offset cannot be larger than the end offset. Asking for
a range that is outside of the file size makes the variable contents empty.
For example, getting the first one hundred bytes from a given file:
curl --variable "fraction[0-99]@filename"
Given a byte range that has no data results in an empty string. Asking for a range that is larger than the content makes curl use the piece of the data that exists.
To assign a variable using contents from another variable, use --expand-variable. Like for example assigning a new variable using contents from two other:
curl --expand-variable "user={{firstname}} {{lastname}}"
When expanding variables, curl supports a set of functions that can make the variable contents more convenient to use. You apply a function to a variable expansion by adding a colon and then list the desired functions in a comma-separated list that is evaluated in a left-to-right order. Variable content holding null bytes that are not encoded when expanded, causes an error.
Available functions:
trim
removes all leading and trailing white space.
Example:
curl --expand-url https://example.com/{{var:trim}}
json
outputs the content using JSON string quoting rules.
Example:
curl --expand-data {{data:json}} https://example.com
url
shows the content URL (percent) encoded.
Example:
curl --expand-url https://example.com/{{path:url}}
b64
expands the variable base64 encoded
Example:
curl --expand-url https://example.com/{{var:b64}}
64dec
decodes a base64 encoded character sequence. If the sequence is not possible
to decode, it instead outputs [64dec-fail]
Example:
curl --expand-url https://example.com/{{var:64dec}}
(Added in 8.13.0)