gsu: Improve documentation of _gsu_get_command_regex().

[gsu.git] / misc / gsu / subcommand

diff --git a/misc/gsu/subcommand b/misc/gsu/subcommand
index 3a1bc6db6697c7a0676a45ae940b930d18ee8901..a04b8dece11660f1b95946c8108f5f9ceacf8a76 100644 (file)
--- a/misc/gsu/subcommand
+++ b/misc/gsu/subcommand
@@ -2,7 +2,7 @@
 # (C) 2006-2011 Andre Noll
 
 if [[ $(type -t gsu_is_a_number) != "function" ]]; then
-       GSU_DIR=${GSU_DIR:=$HOME/.gsu}
+       GSU_DIR=${GSU_DIR:=${HOME-}/.gsu}
        . $GSU_DIR/common || exit 1
 fi
 
@@ -11,8 +11,16 @@ _gsu_usage()
        gsu_short_msg "# Usage: $_gsu_self command [options]"
 }
 
-# Each line matching this is recognized as a subcommand. The name of the may be
-# given as $1. In any case the subcommand is the first subexpression.
+# Return an extended regular expression to match against $0.
+#
+# When called without argument, the expression matches all lines which define a
+# subcommand.
+#
+# If an argument is given, the returned expression matches only the subcommand
+# passed as $1. This is useful to tell if a string is a valid subcommand.
+#
+# Regardless of whether an argument is given, the returned expression contains
+# exactly one parenthesized subexpression for matching the command name.
 _gsu_get_command_regex()
 {
        local cmd="${1:-[-a-zA-Z_0-9]+}"
@@ -90,7 +98,7 @@ options, the command prints out a list of all cmt config variables, together
 with their current value and the default value."
 _com_prefs()
 {
-       local i conf="${gsu_config_file:=$HOME/.$gsu_name.rc}"
+       local i conf="${gsu_config_file:=${HOME:-}/.$gsu_name.rc}"
 
        gsu_getopts "e"
        eval "$result"