📄 list.c
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/* List a tar archive. Copyright (C) 1988 Free Software FoundationThis file is part of GNU Tar.GNU Tar is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe Free Software Foundation; either version 1, or (at your option)any later version.GNU Tar is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See theGNU General Public License for more details.You should have received a copy of the GNU General Public Licensealong with GNU Tar; see the file COPYING. If not, write tothe Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. *//* * List a tar archive. * * Also includes support routines for reading a tar archive. * * this version written 26 Aug 1985 by John Gilmore (ihnp4!hoptoad!gnu). * * @(#)list.c 1.31 11/5/87 - gnu */#include <stdio.h>#include <ctype.h>#include <sys/types.h>#include <sys/stat.h>#ifndef MSDOS#include <sys/file.h>#endif /* MSDOS */#ifdef USG#include <sys/sysmacros.h> /* major() and minor() defined here */#endifchar *ctime(); /* From libc.a */#define isodigit(c) ( ((c) >= '0') && ((c) <= '7') )#include "tar.h"#include "port.h"extern FILE *msg_file;long from_oct(); /* Decode octal number */void demode(); /* Print file mode */union record *head; /* Points to current archive header */struct stat hstat; /* Stat struct corresponding */int head_standard; /* Tape header is in ANSI format */void print_header();void skip_file();void skip_extended_headers();extern char *quote_copy_string();/* * Main loop for reading an archive. */voidread_and(do_something) void (*do_something)();{ int status = 3; /* Initial status at start of archive */ int prev_status; extern time_t new_time; char save_linkflag; name_gather(); /* Gather all the names */ open_archive(1); /* Open for reading */ for(;;) { prev_status = status; status = read_header(); switch (status) { case 1: /* Valid header */ /* We should decode next field (mode) first... */ /* Ensure incoming names are null terminated. */ head->header.name[NAMSIZ-1] = '\0'; if ( !name_match(head->header.name) || (f_new_files && hstat.st_mtime<new_time) || (f_exclude && check_exclude(head->header.name))) { int isextended = 0; /* Skip past it in the archive */ if (head->header.isextended) isextended = 1; save_linkflag = head->header.linkflag; userec(head); if (isextended) {/* register union record *exhdr; for (;;) { exhdr = findrec(); if (!exhdr->ext_hdr.isextended) { userec(exhdr); break; } } userec(exhdr);*/ skip_extended_headers(); } /* Skip to the next header on the archive */ if(save_linkflag != LF_DIR) skip_file((long)hstat.st_size); continue; } (*do_something)(); continue; /* * If the previous header was good, tell them * that we are skipping bad ones. */ case 0: /* Invalid header */ userec(head); switch (prev_status) { case 3: /* Error on first record */ msg("Hmm, this doesn't look like a tar archive."); /* FALL THRU */ case 2: /* Error after record of zeroes */ case 1: /* Error after header rec */ msg("Skipping to next file header...\n"); case 0: /* Error after error */ break; } continue; case 2: /* Record of zeroes */ userec(head); status = prev_status; /* If error after 0's */ if (f_ignorez) continue; /* FALL THRU */ case EOF: /* End of archive */ break; } break; }; close_archive(); names_notfound(); /* Print names not found */} /* * Print a header record, based on tar options. */voidlist_archive(){ extern char *save_name; int isextended = 0; /* Flag to remember if head is extended */ /* Save the record */ saverec(&head); /* Print the header record */ if (f_verbose) { if (f_verbose > 1) decode_header(head, &hstat, &head_standard, 0); print_header(); } if(f_gnudump && head->header.linkflag==LF_DUMPDIR) { size_t size, written, check; char *data; extern int errno; extern long save_totsize; extern long save_sizeleft; userec(head); if(f_multivol) { save_name = head->header.name; save_totsize=hstat.st_size; } for(size = hstat.st_size;size>0;size-=written) { if(f_multivol) save_sizeleft=size; data = findrec()->charptr; if(data==NULL) { msg("EOF in archive file?"); break; } written = endofrecs()->charptr - data; if(written>size) written=size; errno=0; check=fwrite(data,sizeof(char), written, msg_file); userec((union record *)(data+written - 1)); if(check!=written) { msg_perror("only wrote %ld of %ld bytes to file %s",check, written,head->header.name); skip_file((long)(size)-written); break; } } if(f_multivol) save_name = 0; saverec((union record **) 0); /* Unsave it */ fputc('\n',msg_file); fflush(msg_file); return; } saverec((union record **) 0); /* Unsave it */ /* Check to see if we have an extended header to skip over also */ if (head->header.isextended) isextended = 1; /* Skip past the header in the archive */ userec(head); /* * If we needed to skip any extended headers, do so now, by * reading extended headers and skipping past them in the * archive. */ if (isextended) {/* register union record *exhdr; for (;;) { exhdr = findrec(); if (!exhdr->ext_hdr.isextended) { userec(exhdr); break; } userec(exhdr); }*/ skip_extended_headers(); } if(f_multivol) save_name=head->header.name; /* Skip to the next header on the archive */ skip_file((long) hstat.st_size); if(f_multivol) save_name = 0;}/* * Read a record that's supposed to be a header record. * Return its address in "head", and if it is good, the file's * size in hstat.st_size. * * Return 1 for success, 0 if the checksum is bad, EOF on eof, * 2 for a record full of zeros (EOF marker). * * You must always userec(head) to skip past the header which this * routine reads. */intread_header(){ register int i; register long sum, recsum; register char *p; register union record *header; long from_oct(); header = findrec(); head = header; /* This is our current header */ if (NULL == header) return EOF; recsum = from_oct(8, header->header.chksum); sum = 0; p = header->charptr; for (i = sizeof(*header); --i >= 0;) { /* * We can't use unsigned char here because of old compilers, * e.g. V7. */ sum += 0xFF & *p++; } /* Adjust checksum to count the "chksum" field as blanks. */ for (i = sizeof(header->header.chksum); --i >= 0;) sum -= 0xFF & header->header.chksum[i]; sum += ' '* sizeof header->header.chksum; if (sum == recsum) { /* * Good record. Decode file size and return. */ if (header->header.linkflag == LF_LINK) hstat.st_size = 0; /* Links 0 size on tape */ else hstat.st_size = from_oct(1+12, header->header.size); return 1; } if (sum == 8*' ') { /* * This is a zeroed record...whole record is 0's except * for the 8 blanks we faked for the checksum field. */ return 2; } return 0;}/* * Decode things from a file header record into a "struct stat". * Also set "*stdp" to !=0 or ==0 depending whether header record is "Unix * Standard" tar format or regular old tar format. * * read_header() has already decoded the checksum and length, so we don't. * * If wantug != 0, we want the uid/group info decoded from Unix Standard * tapes (for extraction). If == 0, we are just printing anyway, so save time. * * decode_header should NOT be called twice for the same record, since the * two calls might use different "wantug" values and thus might end up with * different uid/gid for the two calls. If anybody wants the uid/gid they * should decode it first, and other callers should decode it without uid/gid * before calling a routine, e.g. print_header, that assumes decoded data. */decode_header(header, st, stdp, wantug) register union record *header; register struct stat *st; int *stdp; int wantug;{ long from_oct(); st->st_mode = from_oct(8, header->header.mode); st->st_mtime = from_oct(1+12, header->header.mtime); if(f_gnudump) { st->st_atime = from_oct(1+12, header->header.atime); st->st_ctime = from_oct(1+12, header->header.ctime); } if (0==strcmp(header->header.magic, TMAGIC)) { /* Unix Standard tar archive */
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