diff options
Diffstat (limited to 'libbb/get_ar_headers.c')
| -rw-r--r-- | libbb/get_ar_headers.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/libbb/get_ar_headers.c b/libbb/get_ar_headers.c new file mode 100644 index 0000000..cf7de5c --- /dev/null +++ b/libbb/get_ar_headers.c @@ -0,0 +1,118 @@ +/* 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); +}
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