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
32 typedef struct ar_headers_s {
40 struct ar_headers_s *next;
44 * return the headerL_t struct for the filename descriptor
46 extern ar_headers_t get_ar_headers(int srcFd)
48 typedef struct raw_ar_header_s { /* Byte Offset */
49 char name[16]; /* 0-15 */
50 char date[12]; /* 16-27 */
52 char gid[6]; /* 28-39 */
53 char mode[8]; /* 40-47 */
54 char size[10]; /* 48-57 */
55 char fmag[2]; /* 58-59 */
58 raw_ar_header_t raw_ar_header;
60 ar_headers_t *head, *entry;
64 head = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
65 entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
68 if (full_read(srcFd, ar_magic, 8) != 8) {
69 error_msg_and_die("cannot read magic");
72 if (strncmp(ar_magic,"!<arch>",7) != 0) {
73 error_msg_and_die("invalid magic");
76 while (full_read(srcFd, (char *) &raw_ar_header, 60)==60) {
77 /* check the end of header markers are valid */
78 if ((raw_ar_header.fmag[0]!='`') || (raw_ar_header.fmag[1]!='\n')) {
80 if (raw_ar_header.fmag[1]!='`') {
83 /* some version of ar, have an extra '\n' after each entry */
84 read(srcFd, &newline, 1);
88 /* fix up the header, we started reading 1 byte too early due to a '\n' */
89 memmove((char *) &raw_ar_header, (char *)&raw_ar_header+1, 59);
90 /* dont worry about adding the last '\n', we dont need it now */
93 entry->size = (size_t) atoi(raw_ar_header.size);
94 /* long filenames have '/' as the first character */
95 if (raw_ar_header.name[0] == '/') {
96 if (raw_ar_header.name[1] == '/') {
97 /* multiple long filenames are stored as data in one entry */
98 long_name = (char *) xrealloc(long_name, entry->size);
99 full_read(srcFd, long_name, entry->size);
103 /* The number after the '/' indicates the offset in the ar data section
104 (saved in variable long_name) that conatains the real filename */
105 const int long_name_offset = (int) atoi((char *) &raw_ar_header.name[1]);
106 entry->name = xmalloc(strlen(&long_name[long_name_offset]));
107 strcpy(entry->name, &long_name[long_name_offset]);
111 /* short filenames */
112 entry->name = xmalloc(16);
113 strncpy(entry->name, raw_ar_header.name, 16);
115 entry->name[strcspn(entry->name, " /")]='\0';
117 /* convert the rest of the now valid char header to its typed struct */
118 parse_mode(raw_ar_header.mode, &entry->mode);
119 entry->mtime = atoi(raw_ar_header.date);
120 entry->uid = atoi(raw_ar_header.uid);
121 entry->gid = atoi(raw_ar_header.gid);
122 entry->offset = lseek(srcFd, 0, SEEK_CUR);
124 /* add this entries header to our combined list */
125 entry->next = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
126 *entry->next = *head;
128 lseek(srcFd, (off_t) entry->size, SEEK_CUR);
133 extern int ar_main(int argc, char **argv)
135 const int preserve_date = 1; /* preserve original dates */
136 const int verbose = 2; /* be verbose */
137 const int display = 4; /* display contents */
138 const int extract_to_file = 8; /* extract contents of archive */
139 const int extract_to_stdout = 16; /* extract to stdout */
141 int funct = 0, opt=0;
142 int srcFd=0, dstFd=0;
144 ar_headers_t head, *extract_list=NULL;
146 extract_list = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
148 while ((opt = getopt(argc, argv, "ovtpx")) != -1) {
151 funct |= preserve_date;
160 funct |= extract_to_stdout;
163 funct |= extract_to_file;
170 /* check the src filename was specified */
174 if ( (srcFd = open(argv[optind], O_RDONLY)) < 0)
175 error_msg_and_die("Cannot read %s", argv[optind]);
178 head = get_ar_headers(srcFd);
180 /* find files to extract or display */
181 /* search through argv and build extract list */
182 for (;optind<argc; optind++) {
183 ar_headers_t *ar_entry;
184 ar_entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
186 while (ar_entry->next != NULL) {
187 if (strcmp(argv[optind], ar_entry->name) == 0) {
189 tmp = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
190 *tmp = *extract_list;
191 *extract_list = *ar_entry;
192 extract_list->next = tmp;
195 ar_entry=ar_entry->next;
199 /* if individual files not found extract all files */
200 if (extract_list->next==NULL) {
201 extract_list = &head;
204 /* find files to extract or display */
205 while (extract_list->next != NULL) {
206 if (funct & extract_to_file) {
207 dstFd = open(extract_list->name, O_WRONLY | O_CREAT, extract_list->mode);
209 else if (funct & extract_to_stdout) {
210 dstFd = fileno(stdout);
212 if ((funct & extract_to_file) || (funct & extract_to_stdout)) {
213 lseek(srcFd, extract_list->offset, SEEK_SET);
214 copy_file_chunk(srcFd, dstFd, (size_t) extract_list->size);
216 if (funct & verbose) {
217 printf("%s %d/%d %8d %s ", mode_string(extract_list->mode),
218 extract_list->uid, extract_list->gid,
219 extract_list->size, time_string(extract_list->mtime));
221 if ((funct & display) || (funct & verbose)){
222 printf("%s\n", extract_list->name);
224 extract_list=extract_list->next;