aboutsummaryrefslogtreecommitdiff
path: root/findutils/xargs.c
blob: 21bfb6bbee5ca6e0b3da66118cdebeb36801b533 (plain)
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
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/* vi: set sw=4 ts=4: */
/*
 * Mini xargs implementation for busybox
 *
 * Copyright (C) 2000 by Lineo, inc.
 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.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
 *
 */

#include "internal.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <getopt.h>
#include <ctype.h>

/* get_sh_safe_line_from_file() - This function reads an entire line from a text file
 * up to a newline. It returns a malloc'ed char * which must be stored and
 * free'ed  by the caller. */
extern char *get_sh_safe_line_from_file(FILE *file)
{
	static const int GROWBY = 80; /* how large we will grow strings by */

	char ch, last_ch = 0;
	char tmp[]=" ";
	int idx = 0;
	char *linebuf = NULL;
	int linebufsz = 0;

	while (1) {
		ch = fgetc(file);
		if (ch == EOF)
			break;
		
		/* grow the line buffer as necessary */
		while (idx > linebufsz-4)
			linebuf = xrealloc(linebuf, linebufsz += GROWBY);

		/* Remove any extra spaces */
		if (last_ch == ' ' && ch == ' ')
			continue;

		/* Replace any tabs with spaces */
		if (ch == '\t')
			ch=' ';

		/* Escape any characters that are treated specially by /bin/sh */
		*tmp=ch;
		if (strpbrk(tmp, "\\~`!$^&*()=|{}[];\"'<>?#") != NULL && last_ch!='\\') {
			linebuf[idx++] = '\\';
		}

		linebuf[idx++] = ch;
		last_ch=ch;

		if (ch == '\n')
			break;
	}
	if (idx == 0 && last_ch!=0)
		linebuf[idx++]=' ';

	if (idx == 0)
		return NULL;

	linebuf[idx] = 0;
	return linebuf;
}



int xargs_main(int argc, char **argv)
{
	char *in_from_stdin = NULL;
	char *args_from_cmdline = NULL;
	char *cmd_to_be_executed = NULL;
	char traceflag = 0;
	int len_args_from_cmdline, len_cmd_to_be_executed, len, opt;

	/* Note that we do not use getopt here, since
	 * we only want to interpret initial options,
	 * not options passed to commands */
	while (--argc && **(++argv) == '-') {
		while (*++(*argv)) {
			switch (**argv) {
				case 't':
					traceflag=1;
					break;
				default:
					fatalError(xargs_usage);
				}
		}
	}

	/* Store the command and arguments to be executed (from the command line) */
	if (argc == 0) {
		len_args_from_cmdline = 6;
		args_from_cmdline = xmalloc(len_args_from_cmdline);
		strcat(args_from_cmdline, "echo ");
	} else {
		opt=strlen(*argv);
		len_args_from_cmdline = (opt > 10)? opt : 10;
		args_from_cmdline = xcalloc(len_args_from_cmdline, sizeof(char));
		while (argc-- > 0) {
			if (strlen(*argv) + strlen(args_from_cmdline) >
				len_args_from_cmdline) {
				len_args_from_cmdline += strlen(*argv);
				args_from_cmdline =
					xrealloc(args_from_cmdline,
							 len_args_from_cmdline+1);
			}
			strcat(args_from_cmdline, *argv);
			strcat(args_from_cmdline, " ");
			++argv;
		}
	}

	/* Set up some space for the command to be executed to be held in */
	len_cmd_to_be_executed=10;
	cmd_to_be_executed = xcalloc(len_cmd_to_be_executed, sizeof(char));
	strcpy(cmd_to_be_executed, args_from_cmdline);

	/* Now, read in one line at a time from stdin, and run command+args on it */
	in_from_stdin = get_sh_safe_line_from_file(stdin);
	for (;in_from_stdin!=NULL;) {
		char *tmp;
		opt = strlen(in_from_stdin);
		len = opt + len_args_from_cmdline;
		len_cmd_to_be_executed+=len+3;
		cmd_to_be_executed=xrealloc(cmd_to_be_executed, len_cmd_to_be_executed);

		/* Strip out the final \n */
		in_from_stdin[opt-1]=' ';
			
		/* trim trailing whitespace */
		opt = strlen(in_from_stdin) - 1;
		while (isspace(in_from_stdin[opt]))
			opt--;
		in_from_stdin[++opt] = 0;

		/* Strip out any leading whitespace */
		tmp=in_from_stdin;
		while(isspace(*tmp))
			tmp++;

		strcat(cmd_to_be_executed, tmp);
		strcat(cmd_to_be_executed, " ");
	
		free(in_from_stdin);
		in_from_stdin = get_sh_safe_line_from_file(stdin);
	}

	if (traceflag==1)
		fputs(cmd_to_be_executed, stderr);

	if ((system(cmd_to_be_executed) != 0) && (errno != 0))
		fatalError("%s", strerror(errno));


#ifdef BB_FEATURE_CLEAN_UP
	free(args_from_cmdline);
	free(cmd_to_be_executed);
#endif

	return 0;
}
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/