diff options
Diffstat (limited to 'src/scripts/xzgrep.in')
| -rw-r--r-- | src/scripts/xzgrep.in | 72 |
1 files changed, 53 insertions, 19 deletions
diff --git a/src/scripts/xzgrep.in b/src/scripts/xzgrep.in index 78f5bd31..c5b89430 100644 --- a/src/scripts/xzgrep.in +++ b/src/scripts/xzgrep.in @@ -182,7 +182,9 @@ for i; do *[-.]zst | *[-.]tzst) uncompress="zstd -cdfq";; # zstd needs -q. *) uncompress="$xz -cdf";; esac - # Fail if xz or grep (or sed) fails. + # xz_status will hold the decompressor's exit status. + # Exit status of grep (and in rare cases, printf or sed) is + # available as the exit status of this assignment command. xz_status=$( exec 5>&1 ($uncompress -- "$i" 5>&-; echo $? >&5) 3>&- | @@ -232,33 +234,65 @@ for i; do # $i already ends with a colon so don't add it here. sed_script="s|^|$i|" - # Fail if grep or sed fails. + # If grep or sed fails, pick the larger value of the two exit statuses. + # If sed fails, use at least 2 since we use >= 2 to indicate errors. r=$( exec 4>&1 (eval "$grep" 4>&-; echo $? >&4) 3>&- | LC_ALL=C sed "$sed_script" >&3 4>&- - ) || r=2 + ) || { + sed_status=$? + test "$sed_status" -lt 2 && sed_status=2 + test "$r" -lt "$sed_status" && r=$sed_status + } exit $r fi >&3 5>&- ) r=$? - # fail occurred previously, nothing worse can happen - test $res -gt 1 && continue - - if test "$xz_status" -eq 0; then - : - elif test "$xz_status" -ge 128 \ - && test "$(kill -l "$xz_status" 2> /dev/null)" = "PIPE"; then - : - else - r=2 + # If grep or sed or other non-decompression command failed with a signal, + # exit immediately and ignore the possible remaining files. + # + # NOTE: Instead of 128 + signal_number, some shells use + # 256 + signal_number (ksh) or 384 + signal_number (yash). + # This is fine for us since their "exit" and "kill -l" commands take + # this into account. (At least the versions I tried do but there is + # a report of an old ksh variant whose "exit" truncates the exit status + # to 8 bits without any special handling for values indicating a signal.) + test "$r" -ge 128 && exit "$r" + + if test -z "$xz_status"; then + # Something unusual happened, for example, we got a signal and + # the exit status of the decompressor was never echoed and thus + # $xz_status is empty. Exit immediately and ignore the possible + # remaining files. + exit 2 + elif test "$xz_status" -ge 128; then + # The decompressor died due to a signal. SIGPIPE is ignored since it can + # occur if grep exits before the whole file has been decompressed (grep -q + # can do that). If the decompressor died with some other signal, exit + # immediately and ignore the possible remaining files. + test "$(kill -l "$xz_status" 2> /dev/null)" != "PIPE" && exit "$xz_status" + elif test "$xz_status" -gt 0; then + # Decompression failed but we will continue with the remaining + # files anwyway. Set exit status to at least 2 to indicate an error. + test "$r" -lt 2 && r=2 fi - # still no match - test $r -eq 1 && continue - - # 0 == match, >=2 == fail - res=$r + # Since res=1 is the initial value, we only need to care about + # matches (r == 0) and errors (r >= 2) here; r == 1 can be ignored. + if test "$r" -ge 2; then + # An error occurred in decompressor, grep, or some other command. Update + # res unless a larger error code has been seen with an earlier file. + test "$res" -lt "$r" && res=$r + elif test "$r" -eq 0; then + # grep found a match and no errors occurred. Update res if no errors have + # occurred with earlier files. + test "$res" -eq 1 && res=0 + fi done -exit $res + +# 0: At least one file matched and no errors occurred. +# 1: No matches were found and no errors occurred. +# >=2: Error. It's unknown if matches were found. +exit "$res" |