busybox/ar.c
Glenn L McGrath 06aeb6c417 ar.c now uses a linked list to process headers, uses getopt, new internal function extractAr(srcFD, dstFd, filename) to make it easily accessable to other busybox functions.
moved copySubFile from ar.c to utilities.c

modified dd.c to use fullWrite

modified copyFile in utilities.c to use copySubFile
2000-08-25 03:50:10 +00:00

217 lines
6.5 KiB
C

/* 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);
}