117 lines
3.3 KiB
C
117 lines
3.3 KiB
C
/*
|
|
* Copyright (c) 1980, 1987 Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#ifndef lint
|
|
char copyright[] =
|
|
"@(#) Copyright (c) 1980, 1987 Regents of the University of California.\n\
|
|
All rights reserved.\n";
|
|
#endif /* not lint */
|
|
|
|
#ifndef lint
|
|
static char sccsid[] = "@(#)head.c 5.5 (Berkeley) 6/1/90";
|
|
#endif /* not lint */
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <ctype.h>
|
|
|
|
static void usage ();
|
|
|
|
/*
|
|
* head - give the first few lines of a stream or of each of a set of files
|
|
*
|
|
* Bill Joy UCB August 24, 1977
|
|
*/
|
|
|
|
main(argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
{
|
|
register int ch, cnt;
|
|
int firsttime, linecnt = 10;
|
|
|
|
/* handle obsolete -number syntax */
|
|
if (argc > 1 && argv[1][0] == '-' && isdigit(argv[1][1])) {
|
|
if ((linecnt = atoi(argv[1] + 1)) < 0) {
|
|
usage ();
|
|
}
|
|
argc--; argv++;
|
|
}
|
|
|
|
while ((ch = getopt (argc, argv, "n:")) != EOF)
|
|
switch (ch) {
|
|
case 'n':
|
|
if ((linecnt = atoi(optarg)) < 0)
|
|
usage ();
|
|
break;
|
|
|
|
default:
|
|
usage();
|
|
}
|
|
argc -= optind, argv += optind;
|
|
|
|
/* setlinebuf(stdout); */
|
|
for (firsttime = 1; ; firsttime = 0) {
|
|
if (!*argv) {
|
|
if (!firsttime)
|
|
exit(0);
|
|
}
|
|
else {
|
|
if (!freopen(*argv, "r", stdin)) {
|
|
fprintf(stderr, "head: can't read %s.\n", *argv);
|
|
exit(1);
|
|
}
|
|
if (argc > 1) {
|
|
if (!firsttime)
|
|
putchar('\n');
|
|
printf("==> %s <==\n", *argv);
|
|
}
|
|
++argv;
|
|
}
|
|
for (cnt = linecnt; cnt; --cnt)
|
|
while ((ch = getchar()) != EOF)
|
|
if (putchar(ch) == '\n')
|
|
break;
|
|
}
|
|
/*NOTREACHED*/
|
|
}
|
|
|
|
|
|
static void
|
|
usage ()
|
|
{
|
|
fputs("usage: head [-n line_count] [file ...]\n", stderr);
|
|
exit(1);
|
|
}
|
|
|