[xzize] Handle short-suffix compressed tar

- Handle short-suffix compressed Tar archives.
- Test separately if a source file exists and is regular.
- Use return value of test_extension() instead of test equality of DEST
  and SOURCE.

compression_utils/README

@@ -23,7 +23,8 @@ The xzize script compresses an uncompressed file, or recompresses a
 compressed file to xz (with maximum compression level).
 
 Known compression formats are GZip (.gz), BZip2 (.bz2), LZMA (.lzma),
-and Lempel-Ziv (.Z).
+and Lempel-Ziv (.Z). Short tar compressed suffixes are also allowed:
+.tgz, .tbz, .tb2, .tlz, .taz.
 
 In case of recompression, the original compressed file is keeped. In
 case of compression (i.e. when the suffix of the file does not

compression_utils/xzize

@@ -8,27 +8,38 @@
 # To Public License, Version 2, as published by Sam Hocevar. See
 # http://sam.zoy.org/wtfpl/COPYING for more details.
 #
-# This script recompresses to xz (with maximum compression level) a
-# GZip (.gz), BZip2 (.bz2), LZMA (.lzma), and Lempel-Ziv (.Z)
-# compressed file. The original file is keeped.
+# This script recompresses to XZ (with maximum compression level) a
+# GZip (.gz, .tgz), BZip2 (.bz2, .tbz, .tb2), LZMA (.lzma, .tlz), and
+# Lempel-Ziv (.Z, .taz) compressed file. The original file is keeped.
 # If the file extension does not correspond to a known compression
-# format, the file is compressed to xz. In that case, the original
+# format, the file is compressed to XZ. In that case, the original
 # file is removed.
+# If the file is already XZ compressed (.xz, .txz), nothing is done.
 
 
 set -u
 
+# Destination file suffix when source file name suffix is a
+# 3-letter compressed tar suffix :
+TAR_XZ_EXT=txz
+
 
 test_extension()
 {
 	local - FILE EXTENSION BASE
 	FILE="$1"
 	EXTENSION="$2"
+	NEWEXTENSION=xz
+	if [ $# -eq 3 ] ; then
+		NEWEXTENSION="$3"
+	fi
+
 	BASE="`basename "$FILE" ."$EXTENSION"`"
 	if [ "$BASE" != "$FILE" ] ; then
-		DEST="$BASE".xz
+		DEST="$BASE".$NEWEXTENSION
 		return 0
 	fi
+
 	DEST="$FILE"
 	return 1
 }
@@ -57,39 +68,76 @@ fi
 ## Process files ##
 
 for SOURCE in "$@" ; do
-	# Regular file?
+	# Does source file exist?
+	if [ ! -e "$SOURCE" ] ; then
+		echo "Skipping source file « $SOURCE »: does not exist!" >&2
+		continue
+	fi
+
+	# Does source file is regular?
 	if [ ! -f "$SOURCE" ] ; then
 		echo "Skipping source file « $SOURCE »: is not a regular file!" >&2
 		continue
 	fi
 
 	# GZip
-	test_extension "$SOURCE" gz
-	if [ "$DEST" != "$SOURCE" ] ; then
+	if test_extension "$SOURCE" gz ; then
+		ACTION=gunzip
+		do_recompress
+		continue
+	fi
+
+	# GZipped Tar (.tgz)
+	if test_extension "$SOURCE" tgz $TAR_XZ_EXT ; then
 		ACTION=gunzip
 		do_recompress
 		continue
 	fi
 
 	# BZip2
-	test_extension "$SOURCE" bz2
-	if [ "$DEST" != "$SOURCE" ] ; then
+	if test_extension "$SOURCE" bz2 ; then
+		ACTION=bunzip2
+		do_recompress
+		continue
+	fi
+
+	# BZipped Tar (.tbz)
+	if test_extension "$SOURCE" tbz $TAR_XZ_EXT ; then
+		ACTION=bunzip2
+		do_recompress
+		continue
+	fi
+
+	# BZipped Tar (.tb2)
+	if test_extension "$SOURCE" tb2 $TAR_XZ_EXT ; then
 		ACTION=bunzip2
 		do_recompress
 		continue
 	fi
 
 	# LZMA
-	test_extension "$SOURCE" lzma
-	if [ "$DEST" != "$SOURCE" ] ; then
+	if test_extension "$SOURCE" lzma ; then
+		ACTION=unlzma
+		do_recompress
+		continue
+	fi
+
+	# LZMA compressed Tar (.tlz)
+	if test_extension "$SOURCE" tlz $TAR_XZ_EXT ; then
 		ACTION=unlzma
 		do_recompress
 		continue
 	fi
 
 	# Compress
-	test_extension "$SOURCE" Z
-	if [ "$DEST" != "$SOURCE" ] ; then
+	if test_extension "$SOURCE" Z ; then
+		ACTION=uncompress
+		do_recompress
+		continue
+	fi
+
+	# Compressed Tar (.taz)
+	if test_extension "$SOURCE" taz $TAR_XZ_EXT ; then
 		ACTION=uncompress
 		do_recompress
 		continue
@@ -101,6 +149,12 @@ for SOURCE in "$@" ; do
 		continue
 	fi
 
+	# XZipped Tar (.txz)
+	if test_extension "$SOURCE" txz $TAR_XZ_EXT ; then
+		echo "Skipping source file « $DEST »: seems to be a XZipped Tar archive (.txz suffix)!" >&2
+		continue
+	fi
+
 	# Uncompressed file: fall back to simple compression
 	echo "Compressing « $SOURCE » to xz…"
 	xz -9 "$SOURCE"