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