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@netconnect.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
24 * Last modified 10 June 2000
34 #include <sys/types.h>
37 #define AR_BLOCK_SIZE 60
38 #define AR_PRESERVE_DATE 1 /* preserve original dates */
39 #define AR_VERBOSE 2 /* be verbose */
40 #define AR_DISPLAY 4 /* display contents */
41 #define AR_EXT_TO_FILE 8 /* extract contents of archive */
42 #define AR_EXT_TO_STDOUT 16 /* extract to stdout */
44 #define BB_DECLARE_EXTERN
45 #define bb_need_io_error
48 struct ArHeader { /* Byte Offset */
49 char ar_name[16]; /* 0-15 */
50 char ar_date[12]; /* 16-27 */
51 char ar_uid[6], ar_gid[6]; /* 28-39 */
52 char ar_mode[8]; /* 40-47 */
53 char ar_size[10]; /* 48-57 */
54 char ar_fmag[2]; /* 58-59 */
56 typedef struct ArHeader ArHeader;
59 char name[17]; /* File name */
60 time_t date; /* long int, No of seconds since epoch */
61 uid_t uid; /* unsigned int, Numeric UID */
62 gid_t gid; /* unsigned int, Numeric GID */
63 mode_t mode; /* unsigned int, Unix mode */
64 size_t size; /* int, Size of the file */
66 typedef struct ArInfo ArInfo;
69 * Display details of a file, verbosly if funct=2
71 static void displayEntry(struct ArInfo *entry, int funct)
73 /* TODO convert mode to string */
74 if ((funct & AR_VERBOSE) == AR_VERBOSE)
75 printf("%i %i/%i %8i %s ", entry->mode, entry->uid, entry->gid,
76 entry->size, timeString(entry->date));
77 printf("%s\n", entry->name);
80 /* this is from tar.c remove later*/
81 static long getOctal(const char *cp, int size)
85 for(;(size > 0) && (*cp == ' '); cp++, size--);
86 if ((size == 0) || !isOctal(*cp))
88 for(; (size > 0) && isOctal(*cp); size--) {
89 val = val * 8 + *cp++ - '0';
91 for (;(size > 0) && (*cp == ' '); cp++, size--);
92 if ((size > 0) && *cp)
98 * Converts from the char based struct to a new struct with stricter types
100 static int processArHeader(struct ArHeader *rawHeader, struct ArInfo *header)
105 /* check end of header marker is valid */
106 if ((rawHeader->ar_fmag[0]!='`') || (rawHeader->ar_fmag[1]!='\n'))
109 /* convert filename */
110 for (count = 0; count < 16; count++) {
111 /* allow spaces in filename except at the end */
112 if (rawHeader->ar_name[count] == ' ') {
113 for (count2 = count; count2 < 16; count2++)
114 if (!isspace(rawHeader->ar_name[count2]))
119 /* GNU ar uses '/' as an end of filename marker */
120 if (rawHeader->ar_name[count] == '/')
122 header->name[count] = rawHeader->ar_name[count];
124 header->name[count] = '\0';
125 header->date = atoi(rawHeader->ar_date);
126 header->uid = atoi(rawHeader->ar_uid);
127 header->gid = atoi(rawHeader->ar_gid);
128 header->mode = getOctal(rawHeader->ar_mode, sizeof(rawHeader->ar_mode));
129 header->size = atoi(rawHeader->ar_size);
134 * Copy size bytes from current position if srcFd to current position in dstFd
135 * taken from tarExtractRegularFile in tar.c, remove later
137 static int copySubFile(int srcFd, int dstFd, int copySize)
139 int readSize, writeSize, doneSize;
142 while (copySize > 0) {
143 if (copySize > BUFSIZ)
147 writeSize = fullRead(srcFd, buffer, readSize);
148 if (writeSize <= 0) {
149 errorMsg(io_error, "copySubFile", strerror(errno));
152 doneSize = fullWrite(dstFd, buffer, writeSize);
154 errorMsg(io_error, "copySubFile", strerror(errno));
157 copySize -= doneSize;
163 * Extract the file described in ArInfo to the specified path
164 * set the new files uid, gid and mode
166 static int extractToFile(struct ArInfo *file, int funct, int srcFd, const char *path)
170 char *pathname = NULL;
171 struct utimbuf newtime;
173 if ((temp = isDirectory(path, TRUE, &tmpStat)) != TRUE) {
174 if (!createPath(path, 0777)) {
175 fatalError("Cannot extract to specified path");
179 temp = (strlen(path) + 16);
180 pathname = (char *) xmalloc(temp);
181 pathname = strcpy(pathname, path);
182 pathname = strcat(pathname, file->name);
183 dstFd = device_open(pathname, O_WRONLY | O_CREAT);
184 temp = copySubFile(srcFd, dstFd, file->size);
185 fchown(dstFd, file->uid, file->gid);
186 fchmod(dstFd, file->mode);
188 if ((funct&AR_PRESERVE_DATE)==AR_PRESERVE_DATE)
189 newtime.modtime=file->date;
191 newtime.modtime=time(0);
192 newtime.actime=time(0);
193 temp = utime(pathname, &newtime);
198 * Return a file descriptor for the specified file and do error checks
200 static int getArFd(char *filename)
205 arFd = open(filename, O_RDONLY);
207 errorMsg("Error opening '%s': %s\n", filename, strerror(errno));
210 if (fullRead(arFd, arVersion, 8) <= 0) {
211 errorMsg( "Unexpected EOF in archive\n");
214 if (strncmp(arVersion,"!<arch>",7) != 0) {
215 errorMsg("ar header fails check ");
222 * Step through the ar file and process it one entry at a time
223 * fileList[0] is the name of the ar archive
224 * fileList[1] and up are filenames to extract from the archive
225 * funct contains flags to specify the actions to be performed
227 static int readArFile(char *fileList[16], int fileListSize, int funct)
229 int arFd, status, extFileFlag, i, lastOffset=0;
230 ArHeader rawArHeader;
233 /* open the ar archive */
234 arFd=getArFd(fileList[0]);
236 /* read the first header, then loop until ono more headers */
237 while ((status = fullRead(arFd, (char *) &rawArHeader, AR_BLOCK_SIZE))
240 /* check the header is valid, if not try reading the header
241 agian with an offset of 1, needed as some ar archive end
242 with a '\n' which isnt counted in specified file size */
243 if ((status=processArHeader(&rawArHeader, &arEntry))==FALSE ) {
244 if ((i=lseek(arFd, 0, SEEK_CUR))==(lastOffset+60))
245 lseek(arFd, lastOffset+1, SEEK_SET);
252 if (funct&AR_DISPLAY)
253 displayEntry(&arEntry, funct);
255 /* check file was specified to be extracted only if
256 some file were specified */
257 if ((funct&AR_EXT_TO_FILE) || (funct&AR_EXT_TO_STDOUT)){
261 for( i=1; i<=fileListSize; i++)
262 if ((status=(strcmp(fileList[i],arEntry.name)))==0)
266 if (extFileFlag==1) {
267 if (funct&AR_EXT_TO_FILE)
268 extractToFile(&arEntry, funct, arFd, "./");
270 copySubFile(arFd,fileno(stdout),arEntry.size);
273 lseek(arFd, arEntry.size, SEEK_CUR);
274 lastOffset=lseek(arFd, 0, SEEK_CUR);
275 } /* if processArHeader */
280 extern int ar_main(int argc, char **argv)
282 int funct = 0, ret=0, i=0;
283 char *fileList[16], c, *opt_ptr;
291 while ((c = *opt_ptr++) != '\0') {
294 funct = funct | AR_PRESERVE_DATE;
297 funct = funct | AR_VERBOSE;
300 funct = funct | AR_DISPLAY;
303 funct = funct | AR_EXT_TO_FILE;
306 funct = funct | AR_EXT_TO_STDOUT;
313 for(i=0; i<(argc-2); i++)
314 fileList[i]=argv[i+2];
317 ret = readArFile(fileList, (argc-2), funct);