bash-completion: handle comma-separated options

This solution can become messy when you have too many options listed,
because it repeats all of them. For example, after invoking completion
with this input:

    $ partx --output END,SECTORS,SCHEME,START,

You got these completions:

    END,SECTORS,SCHEME,START,FLAGS,  END,SECTORS,SCHEME,START,NR,
    END,SECTORS,SCHEME,START,TYPE,
    END,SECTORS,SCHEME,START,NAME,   END,SECTORS,SCHEME,START,SIZE,
    END,SECTORS,SCHEME,START,UUID,

Nevertheless, it works even with numbers (listed options properly
excluded from completion). Try to invoke completion after
'chcpu --disable ' or 'lsblk --exclude ' to see it in action.

Few issues remained:

    * completion interrupts after encountering ':' in listed option,
    like in 'MAJ:MIN' in lsblk, losetup.
    * lscpu completion is broken: it inserts space after '--extended',
    but lscpu assumes there is no space after this option. It also
    doesn't complete '--parse' option.
    * some completion options are outdated (for example, lscpu MMHZ). We
    need to sync them with code. Fix for lscpu follows.

Signed-off-by: Boris Egorov <egorov@linux.com>

1 files changed, 10 insertions, 4 deletions

diff --git a/bash-completion/swapon b/bash-completion/swapon
index f471e079c..fc80af5eb 100644
--- a/bash-completion/swapon
+++ b/bash-completion/swapon
@@ -12,11 +12,17 @@ _swapon_module()
 			return 0
 			;;
 		'--show')
-			# FIXME: how to append to a string with compgen?
-			local OUTPUT
-			OUTPUT="NAME TYPE SIZE USED PRIO UUID LABEL"
+			local prefix realcur OUTPUT_ALL OUTPUT
+			realcur="${cur##*,}"
+			prefix="${cur%$realcur}"
+			OUTPUT_ALL="NAME TYPE SIZE USED PRIO UUID LABEL"
+			for WORD in $OUTPUT_ALL; do
+				if ! [[ $prefix == *"$WORD"* ]]; then
+					OUTPUT="$WORD $OUTPUT"
+				fi
+			done
 			compopt -o nospace
-			COMPREPLY=( $(compgen -W "$OUTPUT" -S ',' -- $cur) )
+			COMPREPLY=( $(compgen -P "$prefix" -W "$OUTPUT" -S ',' -- $realcur) )
 			return 0
 			;;
 		'-U')