139 lines
3.1 KiB
C
139 lines
3.1 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* head implementation for busybox
|
|
*
|
|
* Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
*/
|
|
|
|
/* BB_AUDIT SUSv3 compliant */
|
|
/* BB_AUDIT GNU compatible -c, -q, and -v options in 'fancy' configuration. */
|
|
/* http://www.opengroup.org/onlinepubs/007904975/utilities/head.html */
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <limits.h>
|
|
#include <ctype.h>
|
|
#include <unistd.h>
|
|
#include "busybox.h"
|
|
|
|
static const char head_opts[] =
|
|
"n:"
|
|
#ifdef CONFIG_FEATURE_FANCY_HEAD
|
|
"c:qv"
|
|
#endif
|
|
;
|
|
|
|
static const char header_fmt_str[] = "\n==> %s <==\n";
|
|
|
|
int head_main(int argc, char **argv)
|
|
{
|
|
unsigned long count = 10;
|
|
unsigned long i;
|
|
#ifdef CONFIG_FEATURE_FANCY_HEAD
|
|
int count_bytes = 0;
|
|
int header_threshhold = 1;
|
|
#endif
|
|
|
|
FILE *fp;
|
|
const char *fmt;
|
|
char *p;
|
|
int opt;
|
|
int c;
|
|
int retval = EXIT_SUCCESS;
|
|
|
|
/* Allow legacy syntax of an initial numeric option without -n. */
|
|
if ((argc > 1) && (argv[1][0] == '-')
|
|
/* && (isdigit)(argv[1][1]) */
|
|
&& (((unsigned int)(argv[1][1] - '0')) <= 9)
|
|
) {
|
|
--argc;
|
|
++argv;
|
|
p = (*argv) + 1;
|
|
goto GET_COUNT;
|
|
}
|
|
|
|
while ((opt = getopt(argc, argv, head_opts)) > 0) {
|
|
switch(opt) {
|
|
#ifdef CONFIG_FEATURE_FANCY_HEAD
|
|
case 'q':
|
|
header_threshhold = INT_MAX;
|
|
break;
|
|
case 'v':
|
|
header_threshhold = -1;
|
|
break;
|
|
case 'c':
|
|
count_bytes = 1;
|
|
/* fall through */
|
|
#endif
|
|
case 'n':
|
|
p = optarg;
|
|
GET_COUNT:
|
|
count = bb_xgetularg10(p);
|
|
break;
|
|
default:
|
|
bb_show_usage();
|
|
}
|
|
}
|
|
|
|
argv += optind;
|
|
if (!*argv) {
|
|
*--argv = "-";
|
|
}
|
|
|
|
fmt = header_fmt_str + 1;
|
|
#ifdef CONFIG_FEATURE_FANCY_HEAD
|
|
if (argc - optind <= header_threshhold) {
|
|
header_threshhold = 0;
|
|
}
|
|
#else
|
|
if (argc <= optind + 1) {
|
|
fmt += 11;
|
|
}
|
|
/* Now define some things here to avoid #ifdefs in the code below.
|
|
* These should optimize out of the if conditions below. */
|
|
#define header_threshhold 1
|
|
#define count_bytes 0
|
|
#endif
|
|
|
|
do {
|
|
if ((fp = bb_wfopen_input(*argv)) != NULL) {
|
|
if (fp == stdin) {
|
|
*argv = (char *) bb_msg_standard_input;
|
|
}
|
|
if (header_threshhold) {
|
|
bb_printf(fmt, *argv);
|
|
}
|
|
i = count;
|
|
while (i && ((c = getc(fp)) != EOF)) {
|
|
if (count_bytes || (c == '\n')) {
|
|
--i;
|
|
}
|
|
putchar(c);
|
|
}
|
|
if (bb_fclose_nonstdin(fp)) {
|
|
bb_perror_msg("%s", *argv); /* Avoid multibyte problems. */
|
|
retval = EXIT_FAILURE;
|
|
}
|
|
bb_xferror_stdout();
|
|
}
|
|
fmt = header_fmt_str;
|
|
} while (*++argv);
|
|
|
|
bb_fflush_stdout_and_exit(retval);
|
|
}
|