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_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 */
57 raw_ar_header_t raw_ar_header;
59 ar_headers_t *head, *entry;
63 head = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
64 entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
67 if (full_read(srcFd, ar_magic, 8) != 8)
68 error_msg_and_die("cannot read magic");
69 if (strncmp(ar_magic,"!<arch>",7) != 0)
70 error_msg_and_die("invalid magic");
72 while (full_read(srcFd, (char *) &raw_ar_header, 60)==60) {
73 /* check the end of header markers are valid */
74 if ((raw_ar_header.fmag[0]!='`') || (raw_ar_header.fmag[1]!='\n')) {
76 if (raw_ar_header.fmag[1]!='`') {
79 /* some version of ar, have an extra '\n' after each entry */
80 read(srcFd, newline, 1);
81 if (newline[0]!='\n') {
84 /* fix up the header, we started reading 1 byte too early due to a '\n' */
85 memmove((char *) &raw_ar_header, (char *)&raw_ar_header+1, 59);
86 /* dont worry about adding the last '\n', we dont need it now */
89 entry->size = (size_t) atoi(raw_ar_header.size);
90 /* long filenames have '/' as the first character */
91 if (raw_ar_header.name[0] == '/') {
92 if (raw_ar_header.name[1] == '/') {
93 /* multiple long filenames are stored as data in one entry */
94 long_name = (char *) xrealloc(long_name, entry->size);
95 full_read(srcFd, long_name, entry->size);
99 /* The number after the '/' indicates the offset in the ar data section
100 (saved in variable long_name) that conatains the real filename */
101 const int long_name_offset = (int) atoi((char *) &raw_ar_header.name[1]);
102 entry->name = xmalloc(strlen(&long_name[long_name_offset]));
103 strcpy(entry->name, &long_name[long_name_offset]);
107 /* short filenames */
108 entry->name = xmalloc(16);
109 strncpy(entry->name, raw_ar_header.name, 16);
111 entry->name[strcspn(entry->name, " /")]='\0';
113 /* convert the rest of the now valid char header to its typed struct */
114 parse_mode(raw_ar_header.mode, &entry->mode);
115 entry->mtime = atoi(raw_ar_header.date);
116 entry->uid = atoi(raw_ar_header.uid);
117 entry->gid = atoi(raw_ar_header.gid);
118 entry->offset = lseek(srcFd, 0, SEEK_CUR);
120 /* add this entries header to our combined list */
121 entry->next = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
122 *entry->next = *head;
124 lseek(srcFd, (off_t) entry->size, SEEK_CUR);
129 extern int ar_main(int argc, char **argv)
131 const int preserve_date = 1; /* preserve original dates */
132 const int verbose = 2; /* be verbose */
133 const int display = 4; /* display contents */
134 const int extract_to_file = 8; /* extract contents of archive */
135 const int extract_to_stdout = 16; /* extract to stdout */
137 int funct = 0, opt=0;
138 int srcFd=0, dstFd=0;
140 ar_headers_t head, *extract_list=NULL;
142 extract_list = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
144 while ((opt = getopt(argc, argv, "ovtpx")) != -1) {
147 funct |= preserve_date;
156 funct |= extract_to_stdout;
159 funct |= extract_to_file;
166 /* check the src filename was specified */
170 if ( (srcFd = open(argv[optind], O_RDONLY)) < 0)
171 error_msg_and_die("Cannot read %s", argv[optind]);
174 head = get_headers(srcFd);
176 /* find files to extract or display */
177 /* search through argv and build extract list */
178 for (;optind<argc; optind++) {
179 ar_headers_t *ar_entry;
180 ar_entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
182 while (ar_entry->next != NULL) {
183 if (strcmp(argv[optind], ar_entry->name) == 0) {
185 tmp = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
186 *tmp = *extract_list;
187 *extract_list = *ar_entry;
188 extract_list->next = tmp;
191 ar_entry=ar_entry->next;
195 /* if individual files not found extract all files */
196 if (extract_list->next==NULL) {
197 extract_list = &head;
200 /* find files to extract or display */
201 while (extract_list->next != NULL) {
202 if (funct & extract_to_file) {
203 dstFd = open(extract_list->name, O_WRONLY | O_CREAT, extract_list->mode);
205 else if (funct & extract_to_stdout) {
206 dstFd = fileno(stdout);
208 if ((funct & extract_to_file) || (funct & extract_to_stdout)) {
209 lseek(srcFd, extract_list->offset, SEEK_SET);
210 copy_file_chunk(srcFd, dstFd, (size_t) extract_list->size);
212 if (funct & verbose) {
213 printf("%s %d/%d %8d %s ", mode_string(extract_list->mode),
214 extract_list->uid, extract_list->gid,
215 extract_list->size, time_string(extract_list->mtime));
217 if ((funct & display) || (funct & verbose)){
218 printf("%s\n", extract_list->name);
220 extract_list=extract_list->next;