Update networking layer w/ CURL and emscripten impl

2025-11-08 01:50:36 +11:00
parent a17925904d
commit f6874dc55a
4105 changed files with 694617 additions and 179 deletions
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+<!-- Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. -->
+<!-- SPDX-License-Identifier: curl -->
+# VARIABLES
+curl supports command line variables (added in 8.3.0). Set variables with
+--variable name=content or --variable name@file (where `file` can be stdin if
+set to a single dash (-)).
+
+Variable contents can be expanded in option parameters using `{{name}}` if the
+option name is prefixed with `--expand-`. This gets the contents of the
+variable `name` inserted, or a blank if the name does not exist as a
+variable. Insert `{{` verbatim in the string by prefixing it with a backslash,
+like `\{{`.
+
+You access and expand environment variables by first importing them. You
+select to either require the environment variable to be set or you can provide
+a default value in case it is not already set. Plain `--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 it is not set, use
+`--variable %name=content` or `--variable %name@content`.
+
+Example. Get the USER environment variable into the URL, fail if USER is not
+set:
+
+    --variable '%USER'
+    --expand-url = "https://example.com/api/{{USER}}/method"
+
+When expanding variables, curl supports a set of functions that can make the
+variable contents more convenient to use. It can trim leading and trailing
+white space with `trim`, it can output the contents as a JSON quoted string
+with `json`, URL encode the string with `url`, base64 encode it with `b64` and
+base64 decode it with `64dec`. To apply functions to a variable expansion, add
+them colon separated to the right side of the variable. Variable content
+holding null bytes that are not encoded when expanded causes an error.
+
+Example: get the contents of a file called $HOME/.secret into a variable
+called "fix". Make sure that the content is trimmed and percent-encoded when
+sent as POST data:
+
+    --variable %HOME
+    --expand-variable fix@{{HOME}}/.secret
+    --expand-data "{{fix:trim:url}}"
+    https://example.com/
+
+Command line variables and expansions were added in 8.3.0.