1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
/* vi: set sw=4 ts=4: */
/*
* Mini head implementation for busybox
*
*
* Copyright (C) 1999,2000,2001 by Lineo, inc.
* Written by John Beppu <beppu@lineo.com>
*
* 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
*
*/
#include <errno.h>
#include <stdio.h>
#include <getopt.h>
#include <stdlib.h>
#include <string.h>
#include "busybox.h"
int head(int len, FILE *fp)
{
int i;
char *input;
for (i = 0; i < len; i++) {
if ((input = get_line_from_file(fp)) == NULL)
break;
fputs(input, stdout);
free(input);
}
return 0;
}
/* BusyBoxed head(1) */
int head_main(int argc, char **argv)
{
FILE *fp;
int need_headers, opt, len = 10, status = EXIT_SUCCESS;
/* parse argv[] */
while ((opt = getopt(argc, argv, "n:")) > 0) {
switch (opt) {
case 'n':
len = atoi(optarg);
if (len >= 1)
break;
/* fallthrough */
default:
show_usage();
}
}
/* get rest of argv[] or stdin if nothing's left */
if (argv[optind] == NULL) {
head(len, stdin);
return status;
}
need_headers = optind != (argc - 1);
while (argv[optind]) {
if (strcmp(argv[optind], "-") == 0) {
fp = stdin;
argv[optind] = "standard input";
} else {
if ((fp = wfopen(argv[optind], "r")) == NULL)
status = EXIT_FAILURE;
}
if (fp) {
if (need_headers) {
printf("==> %s <==\n", argv[optind]);
}
head(len, fp);
if (errno) {
perror_msg("%s", argv[optind]);
status = EXIT_FAILURE;
errno = 0;
}
if (optind < argc - 1)
putchar('\n');
if (fp != stdin)
fclose(fp);
}
optind++;
}
return status;
}
|
