From 24a656c2914ab81bda4e535248bdee2ee6e48ceb Mon Sep 17 00:00:00 2001 From: Kyle Evans Date: Tue, 8 May 2018 03:53:46 +0000 Subject: [PATCH] bsdgrep: Allow "-" to be passed to -f to mean "standard input" A version of this patch was originally sent to me by se@, matching behavior from newer versions of GNU grep. While there have been some differences of opinion on whether stdin should be closed or not after depleting it in process of -f, I've opted to leave stdin open and just let the later matching stuff fail and result in a no-match. I'm not married to the current behavior- it was generally chosen since we are adopting this in particular from GNU grep, and I would like to stay consistent without a strong argument to the contrary. The current behavior isn't technically wrong, it's just fairly unfriendly to the developer-user of grep that may not realize their usage is trivially invalid. Submitted by: se --- usr.bin/grep/grep.1 | 9 ++++++++- usr.bin/grep/grep.c | 7 +++++-- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/usr.bin/grep/grep.1 b/usr.bin/grep/grep.1 index 1cc72ea239e1..1aa72155a57d 100644 --- a/usr.bin/grep/grep.1 +++ b/usr.bin/grep/grep.1 @@ -30,7 +30,7 @@ .\" .\" @(#)grep.1 8.3 (Berkeley) 4/18/94 .\" -.Dd April 25, 2018 +.Dd May 7, 2018 .Dt GREP 1 .Os .Sh NAME @@ -404,6 +404,13 @@ and block buffered otherwise. .El .Pp If no file arguments are specified, the standard input is used. +Additionally, +.Dq - +may be used in place of a file name, anywhere that a file name is accepted, to +read from standard input. +This includes both +.Fl f +and file arguments. .Sh EXIT STATUS The .Nm grep diff --git a/usr.bin/grep/grep.c b/usr.bin/grep/grep.c index 827c6b987a0f..3d22b3fb1259 100644 --- a/usr.bin/grep/grep.c +++ b/usr.bin/grep/grep.c @@ -307,7 +307,9 @@ read_patterns(const char *fn) size_t len; ssize_t rlen; - if ((f = fopen(fn, "r")) == NULL) + if (strcmp(fn, "-") == 0) + f = stdin; + else if ((f = fopen(fn, "r")) == NULL) err(2, "%s", fn); if ((fstat(fileno(f), &st) == -1) || (S_ISDIR(st.st_mode))) { fclose(f); @@ -324,7 +326,8 @@ read_patterns(const char *fn) free(line); if (ferror(f)) err(2, "%s", fn); - fclose(f); + if (strcmp(fn, "-") != 0) + fclose(f); } static inline const char *