From: Pádraig Brady Date: Wed, 27 Mar 2013 11:06:00 +0000 (+0000) Subject: shuf: exit without reading if would never output X-Git-Tag: v8.22~168 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f7867e73caac82349e5623d04e46aaf784778644;p=thirdparty%2Fcoreutils.git shuf: exit without reading if would never output * src/shuf.c (main): If -n0 specified then no data would ever be output, so exit without reading input. * tests/misc/shuf.sh: Augment the related test with this case. --- diff --git a/src/shuf.c b/src/shuf.c index bbf3a86c27..0fabb0bfeb 100644 --- a/src/shuf.c +++ b/src/shuf.c @@ -463,7 +463,8 @@ main (int argc, char **argv) break; case 1: - if (! (STREQ (operand[0], "-") || freopen (operand[0], "r", stdin))) + if (! (STREQ (operand[0], "-") || ! head_lines + || freopen (operand[0], "r", stdin))) error (EXIT_FAILURE, errno, "%s", operand[0]); break; @@ -474,7 +475,8 @@ main (int argc, char **argv) fadvise (stdin, FADVISE_SEQUENTIAL); - if (head_lines != SIZE_MAX && input_size () > RESERVOIR_MIN_INPUT) + if (head_lines != SIZE_MAX && (! head_lines + || input_size () > RESERVOIR_MIN_INPUT)) { use_reservoir_sampling = true; n_lines = SIZE_MAX; /* unknown number of input lines, for now. */ diff --git a/tests/misc/shuf.sh b/tests/misc/shuf.sh index 9c9526d4d0..171b25a1fd 100755 --- a/tests/misc/shuf.sh +++ b/tests/misc/shuf.sh @@ -57,4 +57,10 @@ cmp out exp || { fail=1; echo "missing NUL terminator?" 1>&2; } timeout 10 shuf -i1-$SIZE_MAX -n2 >/dev/null || { fail=1; echo "couldn't get a small subset" >&2; } +# Ensure shuf -n0 doesn't read any input or open specified files +touch unreadable || framework_failure_ +chmod 0 unreadable || framework_failure_ +shuf -n0 unreadable || fail=1 +shuf -n1 unreadable && fail=1 + Exit $fail