/* vi: set sw=4 ts=4: */ /* * Mini ar implementation for busybox * * Copyright (C) 2000 by Glenn McGrath * Written by Glenn McGrath <bug1@optushome.com.au> 1 June 2000 * * 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 * */ #include <fcntl.h> #include <string.h> #include <stdlib.h> #include <getopt.h> #include <unistd.h> #include "busybox.h" typedef struct ar_headers_s { char *name; size_t size; uid_t uid; gid_t gid; mode_t mode; time_t mtime; off_t offset; struct ar_headers_s *next; } ar_headers_t; /* * return the headerL_t struct for the filename descriptor */ 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 = (size_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); } extern int ar_main(int argc, char **argv) { const int preserve_date = 1; /* preserve original dates */ const int verbose = 2; /* be verbose */ const int display = 4; /* display contents */ const int extract_to_file = 8; /* extract contents of archive */ const int extract_to_stdout = 16; /* extract to stdout */ int funct = 0, opt=0; int srcFd=0, dstFd=0; ar_headers_t head, *extract_list=NULL; extract_list = (ar_headers_t *) xmalloc(sizeof(ar_headers_t)); while ((opt = getopt(argc, argv, "ovtpx")) != -1) { switch (opt) { case 'o': funct |= preserve_date; break; case 'v': funct |= verbose; break; case 't': funct |= display; break; case 'p': funct |= extract_to_stdout; break; case 'x': funct |= extract_to_file; break; default: show_usage(); } } /* check the src filename was specified */ if (optind == argc) show_usage(); if ( (srcFd = open(argv[optind], O_RDONLY)) < 0) error_msg_and_die("Cannot read %s", argv[optind]); optind++; head = get_ar_headers(srcFd); /* find files to extract or display */ /* search through argv and build extract list */ for (;optind<argc; optind++) { ar_headers_t *ar_entry; ar_entry = (ar_headers_t *) xmalloc(sizeof(ar_headers_t)); ar_entry = &head; while (ar_entry->next != NULL) { if (strcmp(argv[optind], ar_entry->name) == 0) { ar_headers_t *tmp; tmp = (ar_headers_t *) xmalloc(sizeof(ar_headers_t)); *tmp = *extract_list; *extract_list = *ar_entry; extract_list->next = tmp; break; } ar_entry=ar_entry->next; } } /* if individual files not found extract all files */ if (extract_list->next==NULL) { extract_list = &head; } /* find files to extract or display */ while (extract_list->next != NULL) { if (funct & extract_to_file) { dstFd = open(extract_list->name, O_WRONLY | O_CREAT, extract_list->mode); } else if (funct & extract_to_stdout) { dstFd = fileno(stdout); } if ((funct & extract_to_file) || (funct & extract_to_stdout)) { lseek(srcFd, extract_list->offset, SEEK_SET); copy_file_chunk(srcFd, dstFd, (size_t) extract_list->size); } if (funct & verbose) { printf("%s %d/%d %8d %s ", mode_string(extract_list->mode), extract_list->uid, extract_list->gid, extract_list->size, time_string(extract_list->mtime)); } if ((funct & display) || (funct & verbose)){ printf("%s\n", extract_list->name); } extract_list=extract_list->next; } return EXIT_SUCCESS; }