1 /* vi: set sw=4 ts=4: */
3 * Mini ar implementation for busybox
5 * Copyright (C) 2000 by Glenn McGrath
6 * Written by Glenn McGrath <bug1@optushome.com.au> 1 June 2000
8 * Based in part on BusyBox tar, Debian dpkg-deb and GNU ar.
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28 typedef struct ar_headers_s {
36 struct ar_headers_s *next;
40 * return the headerL_t struct for the filename descriptor
42 static ar_headers_t get_headers(int srcFd)
44 typedef struct raw_ar_header_s { /* Byte Offset */
45 char name[16]; /* 0-15 */
46 char date[12]; /* 16-27 */
48 char gid[6]; /* 28-39 */
49 char mode[8]; /* 40-47 */
50 char size[10]; /* 48-57 */
51 char fmag[2]; /* 58-59 */
53 raw_ar_header_t raw_ar_header;
55 ar_headers_t *head, *entry;
59 head = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
60 entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
63 if (full_read(srcFd, ar_magic, 8) != 8)
64 error_msg_and_die("cannot read magic\n");
65 if (strncmp(ar_magic,"!<arch>",7) != 0)
66 error_msg_and_die("invalid magic\n");
68 while (full_read(srcFd, (char *) &raw_ar_header, 60)==60) {
69 /* check the end of header markers are valid */
70 if ((raw_ar_header.fmag[0]!='`') || (raw_ar_header.fmag[1]!='\n')) {
72 if (raw_ar_header.fmag[1]!='`') {
75 /* some version of ar, have an extra '\n' after each entry */
76 read(srcFd, newline, 1);
77 if (newline[0]!='\n') {
80 /* fix up the header, we started reading 1 byte too early due to a '\n' */
81 memmove((char *) &raw_ar_header, (char *)&raw_ar_header+1, 59);
82 /* dont worry about adding the last '\n', we dont need it now */
85 entry->size = (size_t) atoi(raw_ar_header.size);
86 /* long filenames have '/' as the first character */
87 if (raw_ar_header.name[0] == '/') {
88 if (raw_ar_header.name[1] == '/') {
89 /* multiple long filenames are stored as data in one entry */
90 long_name = (char *) xrealloc(long_name, entry->size);
91 full_read(srcFd, long_name, entry->size);
95 /* The number after the '/' indicates the offset in the ar data section
96 (saved in variable long_name) that conatains the real filename */
97 const int long_name_offset = (int) atoi((char *) &raw_ar_header.name[1]);
98 entry->name = xmalloc(strlen(&long_name[long_name_offset]));
99 strcpy(entry->name, &long_name[long_name_offset]);
103 /* short filenames */
104 entry->name = xmalloc(16);
105 strncpy(entry->name, raw_ar_header.name, 16);
107 entry->name[strcspn(entry->name, " /")]='\0';
109 /* convert the rest of the now valid char header to its typed struct */
110 parse_mode(raw_ar_header.mode, &entry->mode);
111 entry->mtime = atoi(raw_ar_header.date);
112 entry->uid = atoi(raw_ar_header.uid);
113 entry->gid = atoi(raw_ar_header.gid);
114 entry->offset = lseek(srcFd, 0, SEEK_CUR);
116 /* add this entries header to our combined list */
117 entry->next = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
118 *entry->next = *head;
120 lseek(srcFd, (off_t) entry->size, SEEK_CUR);
125 extern int ar_main(int argc, char **argv)
127 const int preserve_date = 1; /* preserve original dates */
128 const int verbose = 2; /* be verbose */
129 const int display = 4; /* display contents */
130 const int extract_to_file = 8; /* extract contents of archive */
131 const int extract_to_stdout = 16; /* extract to stdout */
133 int funct = 0, opt=0;
134 int srcFd=0, dstFd=0;
136 ar_headers_t head, *extract_list=NULL;
138 extract_list = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
140 while ((opt = getopt(argc, argv, "ovtpx")) != -1) {
143 funct |= preserve_date;
152 funct |= extract_to_stdout;
155 funct |= extract_to_file;
162 /* check the src filename was specified */
166 if ( (srcFd = open(argv[optind], O_RDONLY)) < 0)
167 error_msg_and_die("Cannot read %s\n", argv[optind]);
170 head = get_headers(srcFd);
172 /* find files to extract or display */
173 /* search through argv and build extract list */
174 for (;optind<argc; optind++) {
175 ar_headers_t *ar_entry;
176 ar_entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
178 while (ar_entry->next != NULL) {
179 if (strcmp(argv[optind], ar_entry->name) == 0) {
181 tmp = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
182 *tmp = *extract_list;
183 *extract_list = *ar_entry;
184 extract_list->next = tmp;
187 ar_entry=ar_entry->next;
191 /* if individual files not found extract all files */
192 if (extract_list->next==NULL) {
193 extract_list = &head;
196 /* find files to extract or display */
197 while (extract_list->next != NULL) {
198 if (funct & extract_to_file) {
199 dstFd = open(extract_list->name, O_WRONLY | O_CREAT, extract_list->mode);
201 else if (funct & extract_to_stdout) {
202 dstFd = fileno(stdout);
204 if ((funct & extract_to_file) || (funct & extract_to_stdout)) {
205 lseek(srcFd, extract_list->offset, SEEK_SET);
206 copy_file_chunk(srcFd, dstFd, (size_t) extract_list->size);
208 if (funct & verbose) {
209 printf("%s %d/%d %8d %s ", mode_string(extract_list->mode),
210 extract_list->uid, extract_list->gid,
211 extract_list->size, time_string(extract_list->mtime));
213 if ((funct & display) || (funct & verbose)){
214 printf("%s\n", extract_list->name);
216 extract_list=extract_list->next;