+FILTER API
+----------
+By default, filters are separate processes that are executed each time they
+are needed. Alternative technologies may be used by prefixing the filter
+specification with the relevant string; available values are:
+
+'exec:'::
+ The default "one process per filter" mode.
+
+'lua:'::
+ Executes the script using a built-in Lua interpreter. The script is
+ loaded once per execution of cgit, and may be called multiple times
+ during cgit's lifetime, making it a good choice for repeated filters
+ such as the 'email filter'. It responds to three functions:
+
+ 'filter_open(argument1, argument2, argument3, ...)'::
+ This is called upon activation of the filter for a particular
+ set of data.
+ 'filter_write(buffer)'::
+ This is called whenever cgit writes data to the webpage.
+ 'filter_close()'::
+ This is called when the current filtering operation is
+ completed.
+
+ Additionally, cgit exposes to the Lua the following built-in functions:
+
+ 'html(str)'::
+ Writes 'str' to the webpage.
+ 'html_txt(str)'::
+ HTML escapes and writes 'str' to the webpage.
+ 'html_attr(str)'::
+ HTML escapes for an attribute and writes "str' to the webpage.
+ 'html_url_path(str)'::
+ URL escapes for a path and writes 'str' to the webpage.
+ 'html_url_arg(str)'::
+ URL escapes for an argument and writes 'str' to the webpage.
+
+
+Parameters are provided to filters as follows.
+
+about filter::
+ This filter is given a single parameter: the filename of the source
+ file to filter. The filter can use the filename to determine (for
+ example) the type of syntax to follow when formatting the readme file.
+ The about text that is to be filtered is available on standard input
+ and the filtered text is expected on standard output.
+
+commit filter::
+ This filter is given no arguments. The commit message text that is to
+ be filtered is available on standard input and the filtered text is
+ expected on standard output.
+
+source filter::
+ This filter is given a single parameter: the filename of the source
+ file to filter. The filter can use the filename to determine (for
+ example) the syntax highlighting mode. The contents of the source
+ file that is to be filtered is available on standard input and the
+ filtered contents is expected on standard output.
+
+Also, all filters are handed the following environment variables:
+
+- CGIT_REPO_URL (from repo.url)
+- CGIT_REPO_NAME (from repo.name)
+- CGIT_REPO_PATH (from repo.path)
+- CGIT_REPO_OWNER (from repo.owner)
+- CGIT_REPO_DEFBRANCH (from repo.defbranch)
+- CGIT_REPO_SECTION (from repo.section)
+- CGIT_REPO_CLONE_URL (from repo.clone-url)
+
+If a setting is not defined for a repository and the corresponding global
+setting is also not defined (if applicable), then the corresponding
+environment variable will be unset.
+
+
projects / ps-cgit / blobdiff