maint: script diagnostics status cleanup

Problem reported by Bruno Haible (Bug#29266#20).
* NEWS: Mention this.
* gunzip.in, gzexe.in, zcat.in, zcmp.in, zdiff.in, zforce.in:
* zgrep.in, zless.in, zmore.in, znew.in:
Use printf instead of echo if the argument might contain ‘\’, at
least in theory.  Don’t assume printf exits with status 1 on
failure; it might be some other positive status.
* gzexe.in: Use printf consistently instead of echo, and
proscribe it instead of echo.

1 files changed, 20 insertions, 20 deletions

diff --git a/gzexe.in b/gzexe.in
index 87413a3..290fa1c 100644
--- a/gzexe.in
+++ b/gzexe.in
@@ -59,15 +59,15 @@ res=0
 while :; do
   case $1 in
   -d) decomp=1; shift;;
-  --h*) exec echo "$usage";;
-  --v*) exec echo "$version";;
+  --h*) printf '%s\n' "$usage"   || exit 1; exit;;
+  --v*) printf '%s\n' "$version" || exit 1; exit;;
   --) shift; break;;
   *) break;;
   esac
 done
 
 if test $# -eq 0; then
-  echo >&2 "$0: missing operand
+  printf >&2 '%s\n' "$0: missing operand
 Try \`$0 --help' for more information."
   exit 1
 fi
@@ -87,29 +87,29 @@ for i do
   esac
   if test ! -f "$file" || test ! -r "$file"; then
     res=$?
-    echo >&2 "$0: $i is not a readable regular file"
+    printf >&2 '%s\n' "$0: $i is not a readable regular file"
     continue
   fi
   if test $decomp -eq 0; then
     if sed -e 1d -e 2q "$file" | grep "^skip=[0-9][0-9]*$" >/dev/null; then
-      echo >&2 "$0: $i is already gzexe'd"
+      printf >&2 '%s\n' "$0: $i is already gzexe'd"
       continue
     fi
   fi
   if test -u "$file"; then
-    echo >&2 "$0: $i has setuid permission, unchanged"
+    printf >&2 '%s\n' "$0: $i has setuid permission, unchanged"
     continue
   fi
   if test -g "$file"; then
-    echo >&2 "$0: $i has setgid permission, unchanged"
+    printf >&2 '%s\n' "$0: $i has setgid permission, unchanged"
     continue
   fi
   case /$file in
   */basename | */bash | */cat | */chmod | */cp | \
-  */dirname | */echo | */expr | */gzip | \
-  */ln | */mkdir | */mktemp | */mv | */rm | \
+  */dirname | */expr | */gzip | \
+  */ln | */mkdir | */mktemp | */mv | */printf | */rm | \
   */sed | */sh | */sleep | */test | */tail)
-    echo >&2 "$0: $i might depend on itself"; continue;;
+    printf >&2 '%s\n' "$0: $i might depend on itself"; continue;;
   esac
 
   dir=`dirname "$file"` || dir=$TMPDIR
@@ -125,7 +125,7 @@ for i do
     tmp=$dir/gzexe$$
   fi && { cp -p "$file" "$tmp" 2>/dev/null || cp "$file" "$tmp"; } || {
     res=$?
-    echo >&2 "$0: cannot copy $file"
+    printf >&2 '%s\n' "$0: cannot copy $file"
     continue
   }
   if test -w "$tmp"; then
@@ -134,7 +134,7 @@ for i do
     writable=0
     chmod u+w "$tmp" || {
       res=$?
-      echo >&2 "$0: cannot chmod $tmp"
+      printf >&2 '%s\n' "$0: cannot chmod $tmp"
       continue
     }
   fi
@@ -170,7 +170,7 @@ case $0 in
 */*) gztmp=$gztmpdir/`basename "$0"`;;
 esac || { (exit 127); exit 127; }
 
-case `echo X | tail -n +1 2>/dev/null` in
+case `printf 'X\n' | tail -n +1 2>/dev/null` in
 X) tail_n=-n;;
 *) tail_n=;;
 esac
@@ -180,13 +180,13 @@ if tail $tail_n +$skip <"$0" | gzip -cd > "$gztmp"; then
   (sleep 5; rm -fr "$gztmpdir") 2>/dev/null &
   "$gztmp" ${1+"$@"}; res=$?
 else
-  echo >&2 "Cannot decompress $0"
+  printf >&2 '%s\n' "Cannot decompress $0"
   (exit 127); res=127
 fi; exit $res
 EOF
     gzip -cv9 "$file") > "$tmp" || {
       res=$?
-      echo >&2 "$0: compression not possible for $i, file unchanged."
+      printf >&2 '%s\n' "$0: compression not possible for $i, file unchanged."
       continue
     }
 
@@ -198,29 +198,29 @@ EOF
     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
+    case `printf 'X\n' | 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."
+      printf >&2 '%s\n' "$0: $i probably not in gzexe format, file unchanged."
       continue
     }
   fi
   test $writable -eq 1 || chmod u-w "$tmp" || {
     res=$?
-    echo >&2 "$0: $tmp: cannot chmod"
+    printf >&2 '%s\n' "$0: $tmp: cannot chmod"
     continue
   }
   ln -f "$file" "$file~" || {
     res=$?
-    echo >&2 "$0: cannot backup $i as $i~"
+    printf >&2 '%s\n' "$0: cannot backup $i as $i~"
     continue
   }
   mv -f "$tmp" "$file" || {
     res=$?
-    echo >&2 "$0: cannot rename $tmp to $i"
+    printf >&2 '%s\n' "$0: cannot rename $tmp to $i"
     continue
   }
   tmp=