* NEWS: Describe gzexe changes noted below.

* Makefile.am (.in): Don't bother with SEDCMD.  This stuff isn't needed
any more (the hosts it caters to are long extinct), and was questionable
anyway since the code assumes the skip= line was line 2.
* configure.ac (AC_SYS_INTERPRETER, SEDCMD): Remove; no longer needed.

* gzexe.in: Sweep the code and fix some bugs.
My, what sharp teeth you have, gzexe!
The straw that broke this camel's back was Matthew Burgess's bug report
<http://lists.gnu.org/archive/html/bug-gzip/2006-11/msg00012.html>.

(IFS): Set it to the standard value, both here and in the
script gzexe generates.
Check for missing operand after parsing options, not before.
This fixes the case for "cpexe --".
Check for tail -n problem separately in gzexe and in the executable
it generates, in case it's a different 'tail'.
(trap): Remove $tmp only if $tmp is not the empty string.
Preserve exit status.
Don't use the nonstandard (and rarely available) "cpmod" utility.
Don't use "set -C"; it's no longer useful and it breaks things
in some cases.
(main loop): Handle file names beginning with "-".
Exit with status of failing program, not with 1.
Fix some bugs in printing diagnostics, and in quoting.
Require the skip= line to have at least one digit.
Use test -u and test -g rather than using the (less-reliable) ls.
Refuse to compress more programs, e.g., sh.
Use mktemp rather than tempfile.  Build a copy of
the compressed or uncompressed executable in the same
directory as the executable, as that's less likely to go wrong
if disk space is low.  Have the executable exit with status 127,
not 1, if the decompression process fails; this is more compatible
with meta-programs like nohup.  Have the executable
uncompress to a temp file with the same basename as the executable;
this is more likely to go right.  Fix a race condition where the
executable temporarily did not exist (in either old or new forms).
Check for race conditions better when mv fails.  Do not attempt
to use cp to do the real work, only to copy permissions to a temp
file, since we don't want to trash running executables.

1 files changed, 122 insertions, 102 deletions

diff --git a/gzexe.in b/gzexe.in
index 69e8c3f..139ec61 100644
--- a/gzexe.in
+++ b/gzexe.in
@@ -1,4 +1,3 @@
-:
 #!/bin/sh
 # gzexe: compressor for Unix executables.
 # Use this only for binaries that you do not use frequently.
@@ -14,7 +13,7 @@
 # On Ultrix, /bin/sh is too buggy, change the first line to: #!/bin/sh5
 
 
-# Copyright (C) 1998, 2002, 2004 Free Software Foundation
+# Copyright (C) 1998, 2002, 2004, 2006 Free Software Foundation
 # Copyright (C) 1993 Jean-loup Gailly
 
 # This program is free software; you can redistribute it and/or modify
@@ -31,6 +30,11 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+tab='	'
+nl='
+'
+IFS=" $tab$nl"
+
 version='gzexe (gzip) @VERSION@
 Copyright (C) 2006 Free Software Foundation, Inc.
 This is free software.  You may redistribute copies of it under the terms of
@@ -50,10 +54,6 @@ Report bugs to <bug-gzip@gnu.org>.'
 
 
 PATH="BINDIR:$PATH"
-if test $# = 0; then
-  echo "$usage"
-  exit 1
-fi
 
 decomp=0
 res=0
@@ -67,134 +67,154 @@ while :; do
   esac
 done
 
-tmp=gz$$
-trap "rm -f $tmp; exit 1" 1 2 3 5 10 13 15
-
-set -C
-echo hi > $tmp || exit
-if test -z "`(${CPMOD-cpmod} $tmp $tmp) 2>&1`"; then
-  cpmod=${CPMOD-cpmod}
-fi
-
-tail=""
-IFS="${IFS= 	}"; saveifs="$IFS"; IFS="${IFS}:"
-for dir in $PATH; do
-  test -z "$dir" && dir=.
-  if test -f $dir/tail; then
-    tail="$dir/tail"
-    break
-  fi
-done
-IFS="$saveifs"
-if test -z "$tail"; then
-  echo cannot find tail
+if test $# -eq 0; then
+  echo >&2 "$0: missing operand
+Try \`$0 --help' for more information."
   exit 1
 fi
-case `echo foo | $tail -n +1 2>/dev/null` in
-foo) tail="$tail -n";;
-esac
+
+tmp=
+trap '
+  res=$?
+  test -n "$tmp" && rm -f "$tmp"
+  (exit $res); exit $res
+' 0 1 2 3 5 10 13 15
 
 for i do
-  if test ! -f "$i" ; then
-    echo ${x}: $i not a file
-    res=1
+  case $i in
+  -*) file=./$i;;
+  *)  file=$i;;
+  esac
+  if test ! -f "$file" || test ! -r "$file"; then
+    res=$?
+    echo >&2 "$0: $i is not a readable regular file"
     continue
   fi
   if test $decomp -eq 0; then
-    if sed -e 1d -e 2q "$i" | grep "^skip=[0-9]*$" >/dev/null; then
-      echo "${x}: $i is already gzexe'd"
+    if sed -e 1d -e 2q "$file" | grep "^skip=[0-9][0-9]*$" >/dev/null; then
+      echo >&2 "$0: $i is already gzexe'd"
       continue
     fi
   fi
-  if ls -l "$i" | grep '^...[sS]' > /dev/null; then
-    echo "${x}: $i has setuid permission, unchanged"
+  if test -u "$file"; then
+    echo >&2 "$0: $i has setuid permission, unchanged"
     continue
   fi
-  if ls -l "$i" | grep '^......[sS]' > /dev/null; then
-    echo "${x}: $i has setgid permission, unchanged"
+  if test -g "$file"; then
+    echo >&2 "$0: $i has setgid permission, unchanged"
     continue
   fi
-  case "$i" in
-  */gzip | */tail | */sed | */chmod | */ln | */sleep | */rm)
-	echo "${x}: $i would depend on itself"; continue ;;
+  case /$file in
+  */basename | */cat | */chmod | */cp | \
+  */dirname | */echo | */expr | */gzip | \
+  */ln | */mkdir | */mktemp | */mv | */rm | */rmdir | \
+  */sed | */sh | */sleep | */test | */tail)
+    echo >&2 "$0: $i would depend on itself"; continue;;
   esac
-  if test -z "$cpmod"; then
-    cp -p "$i" $tmp 2>/dev/null || cp "$i" $tmp
-    if test -w $tmp 2>/dev/null; then
-      writable=1
-    else
-      writable=0
-      chmod u+w $tmp 2>/dev/null
-    fi
-    : >| $tmp
+
+  dir=`dirname "$file"` || dir=$TMPDIR
+  test -d "$dir" && test -w "$dir" && test -x "$dir" || dir=/tmp
+  test -n "$tmp" && rm -f "$tmp"
+  tmp=`TMPDIR=$dir mktemp -t gzexeXXXXXX` || tmp=$dir/gzexe$$
+  cp -p "$file" "$tmp" 2>/dev/null || cp "$file" "$tmp" || {
+    res=$?
+    echo >&2 "$0: cannot copy $file"
+    continue
+  }
+  if test -w "$tmp"; then
+    writable=1
+  else
+    writable=0
+    chmod u+w "$tmp" || {
+      res=$?
+      echo >&2 "$0: cannot chmod $tmp"
+      continue
+    }
   fi
   if test $decomp -eq 0; then
-    (sed 1q $0 &&
-     sed "s|^if tail|if $tail|" <<'EOF' &&
-skip=26
-set -C
+    (cat <<'EOF' &&
+#!/bin/sh
+skip=43
+
+tab='	'
+nl='
+'
+IFS=" $tab$nl"
+
 umask=`umask`
 umask 77
-if (tempfile --version) >/dev/null 2>&1
-then gztmp=`tempfile -p gztmp` || exit
-else gztmp=/tmp/gztmp$$
-fi
-if tail +$skip "$0" | "BINDIR"/gzip -cd > "$gztmp"; then
+
+gztmpdir=
+trap '
+  res=$?
+  test -n "$gztmpdir" && rm -fr "$gztmpdir"
+  (exit $res); exit $res
+' 0 1 2 3 5 10 13 15
+
+gztmpdir=`(mktemp -dt) 2>/dev/null` ||
+  { gztmpdir=/tmp/gztmp$$; mkdir $gztmpdir; } ||
+  { (exit 127); exit 127; }
+
+gztmp=$gztmpdir/$0
+case $0 in
+-* | */*'
+') mkdir -p "$gztmp" && rmdir "$gztmp";;
+*/*) gztmp=$gztmpdir/`basename "$0"`;;
+esac || { (exit 127); exit 127; }
+
+case `echo X | tail -n +1 2>/dev/null` in
+X) tail_n=-n;;
+*) tail_n=;;
+esac
+if tail $tail_n +$skip <"$0" | gzip -cd > "$gztmp"; then
   umask $umask
-  /bin/chmod 700 "$gztmp"
-  prog=`echo "$gztmp" | /bin/sed 's|[^/]*$||'; echo $0 | /bin/sed 's|.*/||'`
-  if /bin/ln "$gztmp" "$prog" 2>/dev/null; then
-    trap '/bin/rm -f "$gztmp" "$prog"; exit $res' 0
-    (/bin/sleep 5; /bin/rm -f "$gztmp" "$prog") 2>/dev/null &
-    "$prog" ${1+"$@"}; res=$?
-  else
-    trap '/bin/rm -f "$gztmp"; exit $res' 0
-    (/bin/sleep 5; /bin/rm -f "$gztmp") 2>/dev/null &
-    "$gztmp" ${1+"$@"}; res=$?
-  fi
+  chmod 700 "$gztmp"
+  (sleep 5; rm -fr "$gztmpdir") 2>/dev/null &
+  "$gztmp" ${1+"$@"}; res=$?
 else
-  echo Cannot decompress $0; exit 1
+  echo >&2 "Cannot decompress $0"
+  (exit 127); res=127
 fi; exit $res
 EOF
-     gzip -cv9 "$i") > $tmp || {
-      /bin/rm -f $tmp
-      echo ${x}: compression not possible for $i, file unchanged.
-      res=1
+    gzip -cv9 "$file") > "$tmp" || {
+      res=$?
+      echo >&2 "$0: compression not possible for $i, file unchanged."
       continue
     }
 
   else
     # decompression
-    skip=26
-    if sed -e 1d -e 2q "$i" | grep "^skip=[0-9][0-9]*$" >/dev/null; then
-      eval `sed -e 1d -e 2q "$i"`
-    fi
-    if $tail +$skip "$i" | gzip -cd > $tmp; then
-      :
-    else
-      echo ${x}: $i probably not in gzexe format, file unchanged.
-      res=1
+    skip=43
+    skip_line=`sed -e 1d -e 2q "$file"`
+    case $skip_line in
+    skip=[0-9] | skip=[0-9][0-9] | skip=[0-9][0-9][0-9])
+      eval "$skip_line";;
+    esac
+    case `echo X | tail -n +1 2>/dev/null` in
+    X) tail_n=-n;;
+    *) tail_n=;;
+    esac
+    tail $tail_n +$skip "$file" | gzip -cd > "$tmp" || {
+      res=$?
+      echo >&2 "$0: $i probably not in gzexe format, file unchanged."
       continue
-    fi
+    }
   fi
-  rm -f "$i~"
-  mv "$i" "$i~" || {
-    echo ${x}: cannot backup $i as $i~
-    rm -f $tmp
-    res=1
+  test $writable -eq 1 || chmod u-w "$tmp" || {
+    res=$?
+    echo >&2 "$0: $tmp: cannot chmod"
     continue
   }
-  mv $tmp "$i" || cp -p $tmp "$i" 2>/dev/null || cp $tmp "$i" || {
-    echo ${x}: cannot create $i
-    rm -f $tmp
-    res=1
+  ln -f "$file" "$file~" || {
+    res=$?
+    echo >&2 "$0: cannot backup $i as $i~"
     continue
   }
-  rm -f $tmp
-  if test -n "$cpmod"; then
-    $cpmod "$i~" "$i" 2>/dev/null
-  elif test $writable -eq 0; then
-    chmod u-w $i 2>/dev/null
-  fi
+  mv -f "$tmp" "$file" || {
+    res=$?
+    echo >&2 "$0: cannot rename $tmp to $i"
+    continue
+  }
+  tmp=
 done
-exit $res
+(exit $res); exit $res