cgitrc.5.txt: describe macro expansion of cgitrc options

This is a new feature in cgit-0.9 which was formerly undocumented.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 26 insertions, 4 deletions

diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index 65b210f..10b86f3 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -33,25 +33,25 @@ about-filter::
 	command will be included verbatim on the about page. Default value:
 	none.
 
 agefile::
 	Specifies a path, relative to each repository path, which can be used
 	to specify the date and time of the youngest commit in the repository.
 	The first line in the file is used as input to the "parse_date"
 	function in libgit. Recommended timestamp-format is "yyyy-mm-dd
 	hh:mm:ss". Default value: "info/web/last-modified".
 
 cache-root::
 	Path used to store the cgit cache entries. Default value:
-	"/var/cache/cgit".
+	"/var/cache/cgit". See also: "MACRO EXPANSION".
 
 cache-dynamic-ttl::
 	Number which specifies the time-to-live, in minutes, for the cached
 	version of repository pages accessed without a fixed SHA1. Default
 	value: "5".
 
 cache-repo-ttl::
 	Number which specifies the time-to-live, in minutes, for the cached
 	version of the repository summary page. Default value: "5".
 
 cache-root-ttl::
 	Number which specifies the time-to-live, in minutes, for the cached
@@ -146,25 +146,25 @@ footer::
 	"generated by..." message. Default value: none.
 
 head-include::
 	The content of the file specified with this option will be included
 	verbatim in the html HEAD section on all pages. Default value: none.
 
 header::
 	The content of the file specified with this option will be included
 	verbatim at the top of all pages. Default value: none.
 
 include::
 	Name of a configfile to include before the rest of the current config-
-	file is parsed. Default value: none.
+	file is parsed. Default value: none. See also: "MACRO EXPANSION".
 
 index-header::
 	The content of the file specified with this option will be included
 	verbatim above the repository index. This setting is deprecated, and
 	will not be supported by cgit-1.0 (use root-readme instead). Default
 	value: none.
 
 index-info::
 	The content of the file specified with this option will be included
 	verbatim below the heading on the repository index page. This setting
 	is deprecated, and will not be supported by cgit-1.0 (use root-desc
 	instead). Default value: none.
@@ -228,25 +228,26 @@ nocache::
 
 noplainemail::
 	If set to "1" showing full author email adresses will be disabled.
 	Default value: "0".
 
 noheader::
 	Flag which, when set to "1", will make cgit omit the standard header
 	on all pages. Default value: none. See also: "embedded".
 
 project-list::
 	A list of subdirectories inside of scan-path, relative to it, that
 	should loaded as git repositories. This must be defined prior to
-	scan-path. Default value: none. See also: scan-path.
+	scan-path. Default value: none. See also: scan-path, "MACRO
+	EXPANSION".
 
 readme::
 	Text which will be used as default value for "repo.readme". Default
 	value: none.
 
 remove-suffix::
 	If set to "1" and scan-path is enabled, if any repositories are found
 	with a suffix of ".git", this suffix will be removed for the url and
 	name. Default value: "0". See also: scan-path.
 
 renamelimit::
 	Maximum number of files to consider when detecting renames. The value
@@ -280,25 +281,26 @@ scan-hidden-path::
 	scan-path will stay away from such directories (considered as
 	"hidden"). Note that this does not apply to the ".git" directory in
 	non-bare repos. This must be defined prior to scan-path.
 	Default value: 0. See also: scan-path.
 
 scan-path::
 	A path which will be scanned for repositories. If caching is enabled,
 	the result will be cached as a cgitrc include-file in the cache
 	directory. If project-list has been defined prior to scan-path,
 	scan-path loads only the directories listed in the file pointed to by
 	project-list. Be advised that only the global settings taken
 	before the scan-path directive will be applied to each repository.
-	Default value: none. See also: cache-scanrc-ttl, project-list.
+	Default value: none. See also: cache-scanrc-ttl, project-list,
+	"MACRO EXPANSION".
 
 section::
 	The name of the current repository section - all repositories defined
 	after this option will inherit the current section name. Default value:
 	none.
 
 section-from-path::
 	A number which, if specified before scan-path, specifies how many
 	path elements from each repo path to use as a default section name.
 	If negative, cgit will discard the specified number of path elements
 	above the repo directory. Default value: 0.
 
@@ -441,24 +443,44 @@ REPOSITORY-SPECIFIC CGITRC FILE
 -------------------------------
 When the option "scan-path" is used to auto-discover git repositories, cgit
 will try to parse the file "cgitrc" within any found repository. Such a
 repo-specific config file may contain any of the repo-specific options
 described above, except "repo.url" and "repo.path". Additionally, the "filter"
 options are only acknowledged in repo-specific config files when
 "enable-filter-overrides" is set to "1".
 
 Note: the "repo." prefix is dropped from the option names in repo-specific
 config files, e.g. "repo.desc" becomes "desc".
 
 
+MACRO EXPANSION
+---------------
+The following cgitrc options supports a simple macro expansion feature,
+where tokens prefixed with "$" are replaced with the value of a similary
+named environment variable:
+
+- cache-root
+- include
+- project-list
+- scan-path
+
+Macro expansion will also happen on the content of $CGIT_CONFIG, if
+defined.
+
+One usage of this feature is virtual hosting, which in its simplest form
+can be accomplished by adding the following line to /etc/cgitrc:
+
+	include=/etc/cgitrc.d/$HTTP_HOST
+
+
 EXAMPLE CGITRC FILE
 -------------------
 
 ....
 # Enable caching of up to 1000 output entriess
 cache-size=1000
 
 
 # Specify some default clone prefixes
 clone-prefix=git://example.com ssh://example.com/pub/git http://example.com/git
 
 # Specify the css url