busybox/archival/ar.c

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/* vi: set sw=4 ts=4: */
/*
* Mini ar implementation for busybox
*
* Copyright (C) 2000 by Glenn McGrath
* Written by Glenn McGrath <bug1@netconnect.com.au> 1 June 2000
*
* Modified 8 August 2000 by Glenn McGrath
* - now uses getopt
* - moved copySubFile function to utilities.c
* - creates linked list of all headers
* - easily accessable to other busybox functions
*
* Based in part on BusyBox tar, Debian dpkg-deb and GNU ar.
*
* 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
*
* Last modified 25 August 2000
*/
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <time.h>
#include <utime.h>
#include <sys/types.h>
#include "internal.h"
#define BLOCK_SIZE 60
#define PRESERVE_DATE 1 /* preserve original dates */
#define VERBOSE 2 /* be verbose */
#define DISPLAY 4 /* display contents */
#define EXT_TO_FILE 8 /* extract contents of archive */
#define EXT_TO_STDOUT 16 /* extract to stdout */
#define BB_DECLARE_EXTERN
#define bb_need_io_error
#include "messages.c"
typedef struct rawArHeader { /* Byte Offset */
char name[16]; /* 0-15 */
char date[12]; /* 16-27 */
char uid[6], gid[6]; /* 28-39 */
char mode[8]; /* 40-47 */
char size[10]; /* 48-57 */
char fmag[2]; /* 58-59 */
} rawArHeader_t;
typedef struct headerL {
char name[16];
size_t size;
uid_t uid;
gid_t gid;
mode_t mode;
time_t mtime;
off_t offset;
struct headerL *next;
} headerL_t;
/*
* populate linked list with all ar file entries and offset
*/
static int parseArArchive(int srcFd, headerL_t *current)
{
off_t lastOffset=0, thisOffset=0;
char arVersion[8];
rawArHeader_t rawArHeader;
lseek(srcFd, 0, SEEK_SET);
if (fullRead(srcFd, arVersion, 8) <= 0) {
errorMsg("Invalid header magic\n");
return (FALSE);
}
if (strncmp(arVersion,"!<arch>",7) != 0) {
errorMsg("This doesnt appear to be an ar archive\n");
return(FALSE);
}
while (fullRead(srcFd, (char *) &rawArHeader, 60) == 60) {
if ( (rawArHeader.fmag[0] == '`') &&
(rawArHeader.fmag[1] == '\n')) {
sscanf(rawArHeader.name, "%s", current->name);
parse_mode(rawArHeader.mode, &current->mode);
current->mtime = atoi(rawArHeader.date);
current->uid = atoi(rawArHeader.uid);
current->gid = atoi(rawArHeader.gid);
current->size = (size_t) atoi(rawArHeader.size);
current->offset = lseek(srcFd, 0 , SEEK_CUR);
current->next = (headerL_t *) xmalloc(sizeof(headerL_t));
lastOffset = lseek(srcFd, (off_t) current->size, SEEK_CUR);
current = current->next;
}
else { /* GNU ar has an extra char after data */
thisOffset=lseek(srcFd, 0, SEEK_CUR);
if ( (thisOffset - lastOffset) > ((off_t) 61) )
return(FALSE);
lseek(srcFd, thisOffset - 59, SEEK_SET);
}
}
return(FALSE);
}
/*
* return the headerL_t struct for the specified filename
*/
static headerL_t *getSubFileHeader(int srcFd, const char filename[16])
{
headerL_t *list;
list = xmalloc(sizeof(headerL_t));
parseArArchive(srcFd, list);
while (list->next != NULL) {
if (strncmp(list->name, filename, strlen(filename))==0)
return(list);
list=list->next;
}
return(NULL);
}
/*
* populate linked list with all ar file entries and offset
*/
static int displayEntry(int srcFd, const char filename[16], int funct)
{
headerL_t *file;
if ((file = getSubFileHeader(srcFd, filename)) == NULL)
return(FALSE);
if ((funct & VERBOSE) == VERBOSE) {
printf("%s %d/%d %8d %s ", modeString(file->mode), file->uid, file->gid, file->size, timeString(file->mtime));
}
printf("%s\n", file->name);
return(TRUE);
}
static int extractAr(int srcFd, int dstFd, const char filename[16])
{
headerL_t *file;
if ( (file = getSubFileHeader(srcFd, filename)) == NULL)
return(FALSE);
lseek(srcFd, file->offset, SEEK_SET);
if (copySubFile(srcFd, dstFd, (size_t) file->size) == TRUE)
return(TRUE);
return(FALSE);
}
extern int ar_main(int argc, char **argv)
{
int funct = 0, opt=0;
int srcFd=0, dstFd=0;
while ((opt = getopt(argc, argv, "ovt:p:x:")) != -1) {
switch (opt) {
case 'o':
funct = funct | PRESERVE_DATE;
break;
case 'v':
funct = funct | VERBOSE;
break;
case 't':
funct = funct | DISPLAY;
case 'x':
if (opt=='x') {
funct = funct | EXT_TO_FILE;
}
case 'p':
if (opt=='p') {
funct = funct | EXT_TO_STDOUT;
}
/* following is common to 't','x' and 'p' */
if (optarg == NULL) {
printf("expected a filename\n");
return(FALSE);
}
if ( (srcFd = open(optarg, O_RDONLY)) < 0) {
errorMsg("Cannot read %s\n", optarg);
return (FALSE);
}
break;
default:
usage(ar_usage);
}
}
/* check options not just preserve_dates and/or verbose */
if (funct < 4) {
usage(ar_usage);
return(FALSE);
}
/* find files to extract */
if (optind<argc)
for(; optind < argc; optind++) {
if ( (funct & EXT_TO_FILE) == EXT_TO_FILE) {
dstFd = open(argv[optind], O_WRONLY | O_CREAT);
extractAr(srcFd, dstFd, argv[optind]);
}
if ( (funct & EXT_TO_STDOUT) == EXT_TO_STDOUT)
extractAr(srcFd, fileno(stdout), argv[optind]);
if ( (funct & DISPLAY) == DISPLAY)
displayEntry(srcFd, argv[optind], funct);
}
return (TRUE);
}