From: François Pinard Date: Wed, 16 Nov 1994 02:38:33 +0000 (+0000) Subject: Initial revision X-Git-Url: https://git.brokenzipper.com/gitweb?a=commitdiff_plain;h=4356a8387b4dd80914f930786a3fc469f2ed0739;p=chaz%2Ftar Initial revision --- diff --git a/src/update.c b/src/update.c new file mode 100644 index 0000000..19e98a7 --- /dev/null +++ b/src/update.c @@ -0,0 +1,545 @@ +/* Update a tar archive. + Copyright (C) 1988 Free Software Foundation + +This file is part of GNU Tar. + +GNU Tar 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, 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 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 GNU Tar; see the file COPYING. If not, write to +the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* JF implement the 'r' 'u' and 'A' options for tar. */ +/* The 'A' option is my own invention: It means that the file-names are + tar files, and they should simply be appended to the end of the archive. + No attempt is made to block the reads from the args; if they're on raw + tape or something like that, it'll probably lose. . . */ + +#include +#include +#include +#ifndef STDC_HEADERS +extern int errno; +#endif + +#ifndef NO_MTIO +#include +#include +#endif + +#ifdef BSD42 +#include +#else +#ifndef V7 +#include +#endif +#endif + +#ifndef __MSDOS__ +#include +#include +#endif + +#define STDIN 0 +#define STDOUT 1 + +#include "tar.h" +#include "port.h" +#include "rmt.h" + +int time_to_start_writing = 0; /* We've hit the end of the old stuff, + and its time to start writing new stuff + to the tape. This involves seeking + back one block and re-writing the current + block (which has been changed). */ + +char *output_start; /* Pointer to where we started to write in + the first block we write out. This is used + if we can't backspace the output and have + to null out the first part of the block */ + +extern void skip_file(); +extern void skip_extended_headers(); + +extern union record *head; +extern struct stat hstat; + +void append_file(); +void close_archive(); +int confirm(); +void decode_header(); +void fl_read(); +void fl_write(); +void flush_archive(); +int move_arch(); +struct name *name_scan(); +char *name_from_list(); +void name_expand(); +void name_gather(); +void names_notfound(); +void open_archive(); +int read_header(); +void reset_eof(); +void write_block(); +void write_eot(); + +/* Implement the 'r' (add files to end of archive), and 'u' (add files to + end of archive if they arent there, or are more up to date than the + version in the archive.) commands.*/ +void +update_archive() +{ + int found_end = 0; + int status = 3; + int prev_status; + char *p; + struct name *name; + extern void dump_file(); + + name_gather(); + if(cmd_mode==CMD_UPDATE) + name_expand(); + open_archive(2); /* Open for updating */ + + do { + prev_status=status; + status=read_header(); + switch(status) { + case EOF: + found_end=1; + break; + + case 0: /* A bad record */ + userec(head); + switch(prev_status) { + case 3: + msg("This doesn't look like a tar archive."); + /* FALL THROUGH */ + case 2: + case 1: + msg("Skipping to next header"); + case 0: + break; + } + break; + + /* A good record */ + case 1: + /* printf("File %s\n",head->header.name); */ + /* head->header.name[NAMSIZ-1]='\0'; */ + if(cmd_mode==CMD_UPDATE && (name=name_scan(head->header.name))) { + /* struct stat hstat; */ + struct stat nstat; + int head_standard; + + decode_header(head,&hstat,&head_standard,0); + if(stat(head->header.name,&nstat)<0) { + msg_perror("can't stat %s:",head->header.name); + } else { + if(hstat.st_mtime>=nstat.st_mtime) + name->found++; + } + } + userec(head); + if (head->header.isextended) + skip_extended_headers(); + skip_file((long)hstat.st_size); + break; + + case 2: + ar_record=head; + found_end = 1; + break; + } + } while(!found_end); + + reset_eof(); + time_to_start_writing = 1; + output_start=ar_record->charptr; + + while(p=name_from_list()) { + if(f_confirm && !confirm("add", p)) + continue; + if(cmd_mode==CMD_CAT) + append_file(p); + else + dump_file(p,-1); + } + + write_eot(); + close_archive(); + names_notfound(); +} + +/* Catenate file p to the archive without creating a header for it. It had + better be a tar file or the archive is screwed */ + +void +append_file(p) +char *p; +{ + int fd; + struct stat statbuf; + long bytes_left; + union record *start; + long bufsiz,count; + + if(0 != stat(p,&statbuf) || (fd=open(p,O_RDONLY|O_BINARY))<0) { + msg_perror("can't open file %s",p); + errors++; + return; + } + + bytes_left = statbuf.st_size; + + while(bytes_left>0) { + start=findrec(); + bufsiz=endofrecs()->charptr - start->charptr; + if(bytes_left < bufsiz) { + bufsiz = bytes_left; + count = bufsiz % RECORDSIZE; + if(count) + bzero(start->charptr + bytes_left,(int)(RECORDSIZE-count)); + } + count=read(fd,start->charptr,bufsiz); + if(count<0) { + msg_perror("read error at byte %ld reading %d bytes in file %s",statbuf.st_size-bytes_left,bufsiz,p); + exit(EX_ARGSBAD); /* FOO */ + } + bytes_left-=count; + userec(start+(count-1)/RECORDSIZE); + if(count!=bufsiz) { + msg("%s: file shrunk by %d bytes, yark!",p,bytes_left); + abort(); + } + } + (void)close(fd); +} + +#ifdef DONTDEF +bprint(fp,buf,num) +FILE *fp; +char *buf; +{ + int c; + + if(num==0 || num==-1) + return; + fputs(" '",fp); + while(num--) { + c= *buf++; + if(c=='\\') fputs("\\\\",fp); + else if(c>=' ' && c<='~') + putc(c,fp); + else switch(c) { + case '\n': + fputs("\\n",fp); + break; + case '\r': + fputs("\\r",fp); + break; + case '\b': + fputs("\\b",fp); + break; + case '\0': + /* fputs("\\-",fp); */ + break; + default: + fprintf(fp,"\\%03o",c); + break; + } + } + fputs("'\n",fp); +} +#endif + +int number_of_blocks_read = 0; + +int number_of_new_records = 0; +int number_of_records_needed = 0; + +union record *new_block = 0; +union record *save_block = 0; + +void +junk_archive() +{ + int found_stuff = 0; + int status = 3; + int prev_status; + struct name *name; + + /* int dummy_head; */ + int number_of_records_to_skip = 0; + int number_of_records_to_keep = 0; + int number_of_kept_records_in_block; + int sub_status; + extern int write_archive_to_stdout; + +/* fprintf(stderr,"Junk files\n"); */ + name_gather(); + open_archive(2); + + while(!found_stuff) { + prev_status=status; + status=read_header(); + switch(status) { + case EOF: + found_stuff = 1; + break; + + case 0: + userec(head); + switch(prev_status) { + case 3: + msg("This doesn't look like a tar archive."); + /* FALL THROUGH */ + case 2: + case 1: + msg("Skipping to next header"); + /* FALL THROUGH */ + case 0: + break; + } + break; + + case 1: + /* head->header.name[NAMSIZ-1] = '\0'; */ + /* fprintf(stderr,"file %s\n",head->header.name); */ + if((name=name_scan(head->header.name))==(struct name *)0) { + userec(head); + /* fprintf(stderr,"Skip %ld\n",(long)(hstat.st_size)); */ + if (head->header.isextended) + skip_extended_headers(); + skip_file((long)(hstat.st_size)); + break; + } + name->found = 1; + found_stuff = 2; + break; + + case 2: + found_stuff = 1; + break; + } + } + /* fprintf(stderr,"Out of first loop\n"); */ + + if(found_stuff!=2) { + write_eot(); + close_archive(); + names_notfound(); + return; + } + + if(write_archive_to_stdout) + write_archive_to_stdout = 0; + new_block = (union record *)malloc(blocksize); + if(new_block==0) { + msg("Can't allocate secondary block of %d bytes",blocksize); + exit(EX_SYSTEM); + } + + /* Save away records before this one in this block */ + number_of_new_records=ar_record-ar_block; + number_of_records_needed = blocking - number_of_new_records; + if(number_of_new_records) + bcopy((void *)ar_block,(void *)new_block,(number_of_new_records)*RECORDSIZE); + + /* fprintf(stderr,"Saved %d recs, need %d more\n",number_of_new_records,number_of_records_needed); */ + userec(head); + if (head->header.isextended) + skip_extended_headers(); + skip_file((long)(hstat.st_size)); + found_stuff=0; + /* goto flush_file; */ + + for(;;) { + /* Fill in a block */ + /* another_file: */ + if(ar_record==ar_last) { + /* fprintf(stderr,"New block\n"); */ + flush_archive(); + number_of_blocks_read++; + } + sub_status = read_header(); + /* fprintf(stderr,"Header type %d\n",sub_status); */ + + if(sub_status==2 && f_ignorez) { + userec(head); + continue; + } + if(sub_status==EOF || sub_status==2) { + found_stuff = 1; + bzero(new_block[number_of_new_records].charptr,RECORDSIZE*number_of_records_needed); + number_of_new_records+=number_of_records_needed; + number_of_records_needed = 0; + write_block(0); + break; + } + + if(sub_status==0) { + msg("Deleting non-header from archive."); + userec(head); + continue; + } + + /* Found another header. Yipee! */ + /* head->header.name[NAMSIZ-1] = '\0'; */ + /* fprintf(stderr,"File %s ",head->header.name); */ + if(name=name_scan(head->header.name)) { + name->found = 1; + /* fprintf(stderr,"Flush it\n"); */ + /* flush_file: */ + /* decode_header(head,&hstat,&dummy_head,0); */ + userec(head); + number_of_records_to_skip=(hstat.st_size+RECORDSIZE-1)/RECORDSIZE; + /* fprintf(stderr,"Flushing %d recs from %s\n",number_of_records_to_skip,head->header.name); */ + + while(ar_last-ar_record<=number_of_records_to_skip) { + + /* fprintf(stderr,"Block: %d <= %d ",ar_last-ar_record,number_of_records_to_skip); */ + number_of_records_to_skip -= (ar_last - ar_record); + flush_archive(); + number_of_blocks_read++; + /* fprintf(stderr,"Block %d left\n",number_of_records_to_skip); */ + } + ar_record+=number_of_records_to_skip; + /* fprintf(stderr,"Final %d\n",number_of_records_to_skip); */ + number_of_records_to_skip = 0; + continue; + } + + /* copy_header: */ + new_block[number_of_new_records]= *head; + number_of_new_records++; + number_of_records_needed--; + number_of_records_to_keep=(hstat.st_size+RECORDSIZE-1)/RECORDSIZE; + userec(head); + if(number_of_records_needed==0) + write_block(1); + /* copy_data: */ + number_of_kept_records_in_block = ar_last - ar_record; + if(number_of_kept_records_in_block > number_of_records_to_keep) + number_of_kept_records_in_block = number_of_records_to_keep; + + /* fprintf(stderr,"Need %d kept_in %d keep %d\n",blocking,number_of_kept_records_in_block,number_of_records_to_keep); */ + + while(number_of_records_to_keep) { + int n; + + if(ar_record==ar_last) { + /* fprintf(stderr,"Flush. . .\n"); */ + fl_read(); + number_of_blocks_read++; + ar_record=ar_block; + number_of_kept_records_in_block = blocking; + if(number_of_kept_records_in_block > number_of_records_to_keep) + number_of_kept_records_in_block = number_of_records_to_keep; + } + n = number_of_kept_records_in_block; + if(n>number_of_records_needed) + n = number_of_records_needed; + + /* fprintf(stderr,"Copying %d\n",n); */ + bcopy((void *)ar_record, (void *)(new_block+number_of_new_records), n*RECORDSIZE); + number_of_new_records += n; + number_of_records_needed -= n; + ar_record += n; + number_of_records_to_keep -= n; + number_of_kept_records_in_block -= n; + /* fprintf(stderr,"Now new %d need %d keep %d keep_in %d rec %d/%d\n", + number_of_new_records,number_of_records_needed,number_of_records_to_keep, + number_of_kept_records_in_block,ar_record-ar_block,ar_last-ar_block); */ + + if(number_of_records_needed == 0) { + write_block(1); + } + } + } + + write_eot(); + close_archive(); + names_notfound(); +} + +void +write_block(f) + int f; +{ + /* fprintf(stderr,"Write block\n"); */ + /* We've filled out a block. Write it out. */ + + /* Backspace back to where we started. . . */ + if(archive!=STDIN) + (void)move_arch(-(number_of_blocks_read+1)); + + save_block = ar_block; + ar_block = new_block; + + if(archive==STDIN) + archive=STDOUT; + fl_write(); + + if(archive==STDOUT) + archive=STDIN; + ar_block = save_block; + + if(f) { + /* Move the tape head back to where we were */ + if(archive!=STDIN) + (void)move_arch(number_of_blocks_read); + number_of_blocks_read--; + } + + number_of_records_needed = blocking; + number_of_new_records = 0; +} + +/* Move archive descriptor by n blocks worth. If n is positive we move + forward, else we move negative. If its a tape, MTIOCTOP had better + work. If its something else, we try to seek on it. If we can't + seek, we lose! */ +int +move_arch(n) + int n; +{ + long cur; + +#ifdef MTIOCTOP + struct mtop t; + int er; + + if(n>0) { + t.mt_op = MTFSR; + t.mt_count = n; + } else { + t.mt_op = MTBSR; + t.mt_count = -n; + } + if((er=rmtioctl(archive,MTIOCTOP,&t))>=0) + return 1; + if(errno==EIO && (er=rmtioctl(archive,MTIOCTOP,&t))>=0) + return 1; +#endif + + cur=rmtlseek(archive,0L,1); + cur+=blocksize*n; + + /* fprintf(stderr,"Fore to %x\n",cur); */ + if(rmtlseek(archive,cur,0)!=cur) { + /* Lseek failed. Try a different method */ + msg("Couldn't re-position archive file."); + exit(EX_BADARCH); + } + return 3; +} +