gsu: Overhaul of the rexexp matching for help commands.

[gsu.git] / misc / gsu / subcommand

diff --git a/misc/gsu/subcommand b/misc/gsu/subcommand
index f5f4745a8856920a0203b02039eadce46f4bf2ef..a688ed5855c60c47e099b723bf8b060487a7669a 100644 (file)
--- a/misc/gsu/subcommand
+++ b/misc/gsu/subcommand
@@ -11,16 +11,33 @@ _gsu_usage()
        gsu_short_msg "# Usage: $_gsu_self command [options]"
 }
 
-# Each line matching this is recognized as a subcommand. The name
-# of the subcommand is the first subexpression.
-export gsu_command_regex='^com_\([-a-zA-Z_0-9]\+\)()'
+# Each line matching this is recognized as a subcommand. The name of the may be
+# given as $1. In any case the subcommand is the first subexpression.
+_gsu_get_command_regex()
+{
+       local cmd="${1:-[-a-zA-Z_0-9]+}"
+       result="^com_($cmd)\(\)"
+}
 
 _gsu_available_commands()
 {
+       local ere
+
+       _gsu_get_command_regex
+       ere="$result"
        result="$({
                printf "help\nman\nprefs\ncomplete\n"
-               sed -ne "s/$gsu_command_regex/\1/g;T;p" $0
-               } | sort | tr '\n' ' ')"
+               sed -Ee '
+                       # if line matches, isolate command name
+                       s/'"$ere"'/\1/g
+
+                       # if there is a match, (print it and) start next cycle
+                       t
+
+                       # otherwise delete it
+                       d
+               ' $0
+       } | sort | tr '\n' ' ')"
 }
 
 _gsu_print_available_commands()
@@ -194,7 +211,11 @@ was given.
 
 _com_help()
 {
-       local a b
+       local a b ere tab='     '
+
+       _gsu_get_command_regex
+       ere="$result"
+
        if test -z "$1"; then
                _gsu_banner_msg 2>&1
                _gsu_usage 2>&1
@@ -203,21 +224,28 @@ _com_help()
                        printf "com_man()\n$gsu_man_txt" | head -n 4; echo "--"
                        printf "com_prefs()\n$gsu_prefs_txt" | head -n 4; echo "--"
                        printf "com_complete()\n$gsu_complete_txt" | head -n 4; echo "--"
-                       grep -A 2 "$gsu_command_regex" $0
+                       grep -EA 2 "$ere" $0
                } | grep -v -- '--' \
-                       | sed -e "/$gsu_command_regex/bs" \
-                               -e 'H;$!d;x;s/\n//g;b' \
-                               -e :s \
-                               -e 'x;s/\n//g;${p;x;}' \
-                       | sed -e "s/${gsu_command_regex}#*/\1\t/" \
-                       | sort \
-                       | while read a b; do
-                               printf "$a\t"
-                               if test ${#a} -lt 8; then
-                                       printf "\t"
-                               fi
-                               echo "$b"
-                        done
+                       | sed -En "/$ere/"'!d
+                               # remove everything but the command name
+                               s/^com_(.*)\(\).*/\1/
+
+                               # append tab after short commands (less than 8 chars)
+                               s/^(.{1,7})$/\1'"$tab"'/g
+
+                               # remove next line (should contain only ## anyway)
+                               N
+                               s/#.*//
+
+                               # append next line, removing leading ##
+                               N
+                               s/#+ *//g
+
+                               # replace newline by tab
+                               y/\n/'"$tab"'/
+
+                               # and print the sucker
+                               p'
                echo
                echo "# Try $_gsu_self help <command> for info on <command>."
                ret=$GSU_SUCCESS
@@ -244,13 +272,32 @@ _com_help()
                return
        fi
        ret=$GSU_SUCCESS
-       if grep -q "^com_$1()" $0; then
-               sed -e "1,/^com_$1()$/d" -e '/^{/,$d' -e 's/^## *//' $0
+       _gsu_get_command_regex "$1"
+       ere="$result"
+       if ! grep -Eq "$ere" $0; then
+               _gsu_print_available_commands
+               result="$1"
+               ret=-$E_GSU_BAD_COMMAND
                return
        fi
-       _gsu_print_available_commands
-       result="$1"
-       ret=-$E_GSU_BAD_COMMAND
+       sed -nEe '
+               # only consider lines in the comment of the function
+               /'"$ere"'/,/^[^#]/ {
+
+                       # remove leading ##
+                       s/^## *//
+
+                       # if it did start with ##, jump to label p and print it
+                       tp
+
+                       # otherwise, move on to next line
+                       d
+
+                       # print it
+                       :p
+                       p
+               }
+       ' $0
 }
 
 complete_help()