gno/bin/tail/tail.c
gdr 590e077340 - initial checkin, as submitted by Dave Tribby
- renamed makefile.mk to Makefile
1997-09-17 06:24:18 +00:00

382 lines
9.0 KiB
C

/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Edward Sze-Tyan Wang.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
/*
* Modified for GNO (Apple IIGS) by Dave Tribby, July 1997
*
* Constructs unacceptable to compiler are replaced using #ifndef __ORCAC__
*
* Changes not related to compiler are replaced using #ifndef __GNO__
* (e.g., did not implement -r option)
*
* Added prototyped headers, surrounded by #ifndef __STDC__
*/
#ifndef __GNO__ /* Don't need what strings for GNO */
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1991, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)tail.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#endif __GNO__
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include "extern.h"
int fflag, rflag, rval;
char *fname;
static void obsolete __P((char **));
static void usage __P((void));
/* Interface to check on how much stack space a C program uses. */
#if defined(__GNO__) && defined(__STACK_CHECK__)
#ifndef _STDLIB_H_
#include <stdlib.h>
#endif
extern void begin_stack_check(void);
extern int end_stack_check(void);
static void report_stack(void)
{
fprintf(stderr,"\n ==> %d stack bytes used <== \n", end_stack_check());
}
#endif
int
#ifndef __STDC__
main(argc, argv)
int argc;
char *argv[];
#else
main(int argc,
char *argv[])
#endif
{
struct stat sb;
FILE *fp;
long off;
enum STYLE style;
int ch, first;
char *p;
#if defined(__GNO__) && defined(__STACK_CHECK__)
begin_stack_check();
atexit(report_stack);
#endif
/*
* Tail's options are weird. First, -n10 is the same as -n-10, not
* -n+10. Second, the number options are 1 based and not offsets,
* so -n+1 is the first line, and -c-1 is the last byte. Third, the
* number options for the -r option specify the number of things that
* get displayed, not the starting point in the file. The one major
* incompatibility in this version as compared to historical versions
* is that the 'r' option couldn't be modified by the -lbc options,
* i.e. it was always done in lines. This version treats -rc as a
* number of characters in reverse order. Finally, the default for
* -r is the entire file, not 10 lines.
*/
/* NOTE: for GNO the -r (reverse print) option has been removed */
#define ARG(units, forward, backward) { \
if (style) \
usage(); \
off = strtol(optarg, &p, 10) * (units); \
if (*p) \
errx(1, "illegal offset -- %s", optarg); \
switch(optarg[0]) { \
case '+': \
if (off) \
off -= (units); \
style = (forward); \
break; \
case '-': \
off = -off; \
/* FALLTHROUGH */ \
default: \
style = (backward); \
break; \
} \
}
obsolete(argv);
style = NOTSET;
#ifndef __GNO__ /* -r option not used in GNO */
while ((ch = getopt(argc, argv, "b:c:fn:r")) != -1)
#else
while ((ch = getopt(argc, argv, "b:c:fn:")) != -1)
#endif
switch(ch) {
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;
#ifndef __GNO__
case 'r':
rflag = 1;
break;
#endif
case '?':
default:
usage();
}
argc -= optind;
#ifndef __ORCAC__
argv += optind;
#else
argv = argv + optind;
#endif
if (fflag && argc > 1)
errx(1, "-f option only appropriate for a single file");
#ifndef __GNO__
/*
* If displaying in reverse, don't permit follow option, and convert
* style values.
*/
if (rflag) {
if (fflag)
usage();
if (style == FBYTES)
style = RBYTES;
else if (style == FLINES)
style = RLINES;
}
#endif
/*
* If style not specified, the default is the whole file for -r, and
* the last 10 lines if not -r.
*/
if (style == NOTSET)
#ifndef __GNO__
if (rflag) {
off = 0;
style = REVERSE;
} else {
#else
{
#endif
off = 10;
style = RLINES;
}
if (*argv)
for (first = 1; fname = *argv++;) {
if ((fp = fopen(fname, "r")) == NULL ||
fstat(fileno(fp), &sb)) {
ierr();
continue;
}
if (argc > 1) {
(void)printf("%s==> %s <==\n",
first ? "" : "\n", fname);
first = 0;
(void)fflush(stdout);
}
#ifndef __GNO__
if (rflag)
reverse(fp, style, off, &sb);
else
#endif
forward(fp, style, off, &sb);
(void)fclose(fp);
}
else {
fname = "stdin";
if (fstat(fileno(stdin), &sb)) {
ierr();
exit(1);
}
/*
* Determine if input is a pipe. 4.4BSD will set the SOCKET
* bit in the st_mode field for pipes. Fix this then.
*/
if (lseek(fileno(stdin), (off_t)0, SEEK_CUR) == -1 &&
errno == ESPIPE) {
errno = 0;
fflag = 0; /* POSIX.2 requires this. */
}
#ifndef __GNO__
if (rflag)
reverse(stdin, style, off, &sb);
else
#endif
forward(stdin, style, off, &sb);
}
exit(rval);
}
/*
* Convert the obsolete argument form into something that getopt can handle.
* This means that anything of the form [+-][0-9][0-9]*[lbc][fr] that isn't
* the option argument for a -b, -c or -n option gets converted.
*/
static void
#ifndef __STDC__
obsolete(argv)
char *argv[];
#else
obsolete(char **argv)
#endif
{
register char *ap, *p, *t;
int len;
char *start;
while (ap = *++argv) {
/* Return if "--" or not an option of any form. */
if (ap[0] != '-') {
if (ap[0] != '+')
return;
} else if (ap[1] == '-')
return;
switch(*++ap) {
/* Old-style option. */
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
/* Malloc space for dash, new option and argument. */
len = strlen(*argv);
if ((start = p = malloc(len + 3)) == NULL)
err(1, "malloc");
*p++ = '-';
/*
* Go to the end of the option argument. Save off any
* trailing options (-3lf) and translate any trailing
* output style characters.
*/
t = *argv + len - 1;
#ifndef __GNO__
if (*t == 'f' || *t == 'r') {
#else
if (*t == 'f') {
#endif
*p++ = *t;
*t-- = '\0';
}
switch(*t) {
case 'b':
*p++ = 'b';
*t = '\0';
break;
case 'c':
*p++ = 'c';
*t = '\0';
break;
case 'l':
*t = '\0';
/* FALLTHROUGH */
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
*p++ = 'n';
break;
default:
errx(1, "illegal option -- %s", *argv);
}
*p++ = *argv[0];
(void)strcpy(p, ap);
*argv = start;
continue;
/*
* Options w/ arguments, skip the argument and continue
* with the next option.
*/
case 'b':
case 'c':
case 'n':
if (!ap[1])
++argv;
/* FALLTHROUGH */
/* Options w/o arguments, continue with the next option. */
case 'f':
#ifndef __GNO__
case 'r':
#endif
continue;
/* Illegal option, return and let getopt handle it. */
default:
return;
}
}
}
static void
#ifndef __STDC__
usage()
#else
usage(void)
#endif
{
#ifndef __GNO__
(void)fprintf(stderr,
"usage: tail [-f | -r] [-b # | -c # | -n #] [file ...]\n");
#else /* GNO doesn't implement -r; shows obsolescent form */
(void)fprintf(stderr,
"usage: tail [-f] [-b # | -c # | -n #] [file ...]\n");
(void)fprintf(stderr,
" tail [-f] [+|-#[b|c|l]] [file ...]\n");
#endif
exit(1);
}