On Mon, Oct 02, 2017 at 01:34:26AM +0700, Robert Elz wrote:
> Date: Sun, 1 Oct 2017 11:53:05 -0400
> From: Thor Lancelot Simon <t...@panix.com>
> Message-ID: <20171001155305.ga27...@panix.com>
>
> | It's low risk (unlike, say, modifying the parser in the shell ;-)),
>
> Nah - that's easy, no risk at all!
>
> | And, frankly, I like the name ("tac")
>
> So do I, I used to have a tac command, and I miss it.
>
> coypu - your latest diff still had optind used incorrectly, thoe two optind
> lines should be inside the "if we are tail" { statement-list } after the
> getopt while loop. The tac case isn't using getopt, and so shouldn't be
> using optind either.
>
> And I'd code it as "if we are [not]? tac" rather that "if we are tail" (ie:
> strcmp(..., "tac") rather than tail, just in case someone has tail
> linked to some other name ("lastlines" ??) we don't want to break that
> by turning that into tac rather than tail.
I've done this, and added a man page.
Index: Makefile
===================================================================
RCS file: /cvsroot/src/usr.bin/tail/Makefile,v
retrieving revision 1.3
diff -u -r1.3 Makefile
--- Makefile 23 Nov 1994 07:41:55 -0000 1.3
+++ Makefile 1 Oct 2017 19:22:32 -0000
@@ -1,7 +1,10 @@
# $NetBSD: Makefile,v 1.3 1994/11/23 07:41:55 jtc Exp $
# @(#)Makefile 8.1 (Berkeley) 6/6/93
-
PROG= tail
SRCS= forward.c misc.c read.c reverse.c tail.c
+LINKS= ${BINDIR}/tail ${BINDIR}/tac
+
+MAN= tail.1 tac.1
+
.include <bsd.prog.mk>
Index: tac.1
===================================================================
RCS file: tac.1
diff -N tac.1
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ tac.1 1 Oct 2017 19:22:32 -0000
@@ -0,0 +1,54 @@
+.\" $NetBSD$
+.\"
+.\" Copyright (c) 2017 The NetBSD Foundation, Inc.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to The NetBSD Foundation
+.\" by Maya Rashish.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\"
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in
+.\" the documentation and/or other materials provided with the
+.\" distribution.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+.\" INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
+.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.Dd October 1, 2017
+.Dt TAC 1
+.Os
+.Sh NAME
+.Nm tac
+.Nd display file in reverse
+.Sh SYNOPSIS
+.Nm
+.Op Ar file ...
+.Sh DESCRIPTION
+This displays the contents of each of each of the specified files,
+or of the standard input if no files are specified its standard input,
+in reverse order.
+.Sh EXIT STATUS
+.Ex -std tac
+.Sh COMPATIBILITY
+The
+.Nm
+utility doesn't support any of the options of GNU tac.
+.Sh SEE ALSO
+.Xr cat 1 ,
+.Xr tail 1
Index: tail.1
===================================================================
RCS file: /cvsroot/src/usr.bin/tail/tail.1,v
retrieving revision 1.17
diff -u -r1.17 tail.1
--- tail.1 4 Jul 2017 07:04:50 -0000 1.17
+++ tail.1 1 Oct 2017 19:22:33 -0000
@@ -32,7 +32,7 @@
.\"
.\" @(#)tail.1 8.1 (Berkeley) 6/6/93
.\"
-.Dd June 15, 2014
+.Dd October 1, 2017
.Dt TAIL 1
.Os
.Sh NAME
@@ -43,7 +43,7 @@
.Oo
.Fl f |
.Fl F |
-.Fl r
+.Fl rqv
.Oc
.Oo
.Fl b Ar number |
@@ -133,12 +133,17 @@
option is to display all of the input.
.El
.Pp
-If more than a single file is specified, each file is preceded by a
+If more than a single file is specified, or the
+.Fl v
+option is used, each file is preceded by a
header consisting of the string
.Dq ==> XXX \*[Le]=
where
.Dq XXX
is the name of the file.
+The
+.Fl q
+flag disables the printing of the header in all cases.
.Sh EXIT STATUS
.Ex -std tail
.Sh SEE ALSO
Index: tail.c
===================================================================
RCS file: /cvsroot/src/usr.bin/tail/tail.c,v
retrieving revision 1.17
diff -u -r1.17 tail.c
--- tail.c 31 Jan 2013 23:09:06 -0000 1.17
+++ tail.c 1 Oct 2017 19:22:33 -0000
@@ -67,6 +67,8 @@
enum STYLE style;
int ch, first;
char *p;
+ int qflag = 0;
+ int vflag = 0;
setprogname(argv[0]);
off = 0;
@@ -105,32 +107,48 @@
obsolete(argv);
style = NOTSET;
- while ((ch = getopt(argc, argv, "Fb:c:fn:r")) != -1)
- switch(ch) {
- case 'F':
- fflag = 2;
- break;
- case 'b':
- ARG(512, FBYTES, RBYTES);
- break;
- case 'c':
- ARG(1, FBYTES, RBYTES);
- break;
- case 'f':
- fflag = 1;
- break;
- case 'n':
- ARG(1, FLINES, RLINES);
- break;
- case 'r':
- rflag = 1;
- break;
- case '?':
- default:
- usage();
- }
- argc -= optind;
- argv += optind;
+ if (strcmp(getprogname(), "tac") == 0) {
+ qflag = 1;
+ vflag = 0;
+ rflag = 1;
+ argc -= 1;
+ argv += 1;
+ } else { /* tail */
+ while ((ch = getopt(argc, argv, "Fb:c:fn:rqv")) != -1)
+ switch(ch) {
+ case 'F':
+ fflag = 2;
+ break;
+ case 'b':
+ ARG(512, FBYTES, RBYTES);
+ break;
+ case 'c':
+ ARG(1, FBYTES, RBYTES);
+ break;
+ case 'f':
+ fflag = 1;
+ break;
+ case 'n':
+ ARG(1, FLINES, RLINES);
+ break;
+ case 'r':
+ rflag = 1;
+ break;
+ case 'q':
+ qflag = 1;
+ vflag = 0;
+ break;
+ case 'v':
+ qflag = 0;
+ vflag = 1;
+ break;
+ case '?':
+ default:
+ usage();
+ }
+ argc -= optind;
+ argv += optind;
+ }
if (fflag && argc > 1)
xerrx(1,
@@ -169,7 +187,7 @@
ierr();
continue;
}
- if (argc > 1) {
+ if (vflag || (qflag == 0 && argc > 1)) {
(void)printf("%s==> %s <==\n",
first ? "" : "\n", fname);
first = 0;
@@ -299,7 +317,7 @@
usage(void)
{
(void)fprintf(stderr,
- "Usage: %s [-f | -F | -r] [-b # | -c # | -n #] [file ...]\n",
+ "Usage: %s [-f | -F | -rqv] [-b # | -c # | -n #] [file ...]\n",
getprogname());
exit(1);
}
