zgrep: fix exit status with multiple files

zgrep should exit with success when given multiple files and the
pattern is found in at least one file.  Prior to this change,
it would exit with success only if the pattern was found in _every_ file.

Reviewed by:	dab ngie
MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D26616

1 files changed, 12 insertions, 5 deletions

diff --git a/usr.bin/grep/zgrep.sh b/usr.bin/grep/zgrep.sh
index acbcb48770a7..7e44c7053492 100755
--- a/usr.bin/grep/zgrep.sh
+++ b/usr.bin/grep/zgrep.sh
@@ -157,28 +157,35 @@ then
     pattern_found=1
 fi
 
-ret=0
 # call grep ...
 if [ $# -lt 1 ]
 then
     # ... on stdin
     if [ ${pattern_file} -eq 0 ]; then
-	${cattool} ${catargs} - | ${grep} ${grep_args} -- "${pattern}" - || ret=$?
+	${cattool} ${catargs} - | ${grep} ${grep_args} -- "${pattern}" -
     else
-	${cattool} ${catargs} - | ${grep} ${grep_args} -- - || ret=$?
+	${cattool} ${catargs} - | ${grep} ${grep_args} -- -
     fi
+    ret=$?
 else
     # ... on all files given on the command line
     if [ ${silent} -lt 1 -a $# -gt 1 ]; then
 	grep_args="-H ${grep_args}"
     fi
+    # Succeed if any file matches.  First assume no match.
+    ret=1
     for file; do
 	if [ ${pattern_file} -eq 0 ]; then
 	    ${cattool} ${catargs} -- "${file}" |
-		${grep} --label="${file}" ${grep_args} -- "${pattern}" - || ret=$?
+		${grep} --label="${file}" ${grep_args} -- "${pattern}" -
 	else
 	    ${cattool} ${catargs} -- "${file}" |
-		${grep} --label="${file}" ${grep_args} -- - || ret=$?
+		${grep} --label="${file}" ${grep_args} -- -
+	fi
+	this_ret=$?
+	# A match (0) overrides a no-match (1).  An error (>=2) overrides all.
+	if [ ${this_ret} -eq 0 -a ${ret} -eq 1 ] || [ ${this_ret} -ge 2 ]; then
+	    ret=${this_ret}
 	fi
     done
 fi