hush/libbb/get_ar_headers.c

118 lines
3.8 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) tons of folks. Tracking down who wrote what
* isn't something I'm going to worry about... If you wrote something
* here, please feel free to acknowledge your work.
*
* 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
*
* Based in part on code from sash, Copyright (c) 1999 by David I. Bell
* Permission has been granted to redistribute this code under the GPL.
*
*/
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "libbb.h"
extern ar_headers_t get_ar_headers(int srcFd)
{
typedef struct raw_ar_header_s { /* Byte Offset */
char name[16]; /* 0-15 */
char date[12]; /* 16-27 */
char uid[6];
char gid[6]; /* 28-39 */
char mode[8]; /* 40-47 */
char size[10]; /* 48-57 */
char fmag[2]; /* 58-59 */
} raw_ar_header_t;
raw_ar_header_t raw_ar_header;
ar_headers_t *head, *entry;
char ar_magic[8];
char *long_name=NULL;
head = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
/* check ar magic */
if (full_read(srcFd, ar_magic, 8) != 8) {
error_msg_and_die("cannot read magic");
}
if (strncmp(ar_magic,"!<arch>",7) != 0) {
error_msg_and_die("invalid magic");
}
while (full_read(srcFd, (char *) &raw_ar_header, 60)==60) {
/* check the end of header markers are valid */
if ((raw_ar_header.fmag[0]!='`') || (raw_ar_header.fmag[1]!='\n')) {
char newline;
if (raw_ar_header.fmag[1]!='`') {
break;
}
/* some version of ar, have an extra '\n' after each entry */
read(srcFd, &newline, 1);
if (newline!='\n') {
break;
}
/* fix up the header, we started reading 1 byte too early due to a '\n' */
memmove((char *) &raw_ar_header, (char *)&raw_ar_header+1, 59);
/* dont worry about adding the last '\n', we dont need it now */
}
entry->size = (off_t) atoi(raw_ar_header.size);
/* long filenames have '/' as the first character */
if (raw_ar_header.name[0] == '/') {
if (raw_ar_header.name[1] == '/') {
/* multiple long filenames are stored as data in one entry */
long_name = (char *) xrealloc(long_name, entry->size);
full_read(srcFd, long_name, entry->size);
continue;
}
else {
/* The number after the '/' indicates the offset in the ar data section
(saved in variable long_name) that conatains the real filename */
const int long_name_offset = (int) atoi((char *) &raw_ar_header.name[1]);
entry->name = xmalloc(strlen(&long_name[long_name_offset]));
strcpy(entry->name, &long_name[long_name_offset]);
}
}
else {
/* short filenames */
entry->name = xmalloc(16);
strncpy(entry->name, raw_ar_header.name, 16);
}
entry->name[strcspn(entry->name, " /")]='\0';
/* convert the rest of the now valid char header to its typed struct */
parse_mode(raw_ar_header.mode, &entry->mode);
entry->mtime = atoi(raw_ar_header.date);
entry->uid = atoi(raw_ar_header.uid);
entry->gid = atoi(raw_ar_header.gid);
entry->offset = lseek(srcFd, 0, SEEK_CUR);
/* add this entries header to our combined list */
entry->next = (ar_headers_t *) xmalloc(sizeof(ar_headers_t));
*entry->next = *head;
*head = *entry;
lseek(srcFd, (off_t) entry->size, SEEK_CUR);
}
return(*head);
}