📄 buffer.c
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if(f_multivol) { if(!save_name) { real_s_name[0]='\0'; real_s_totsize=0; real_s_sizeleft = 0; return; }#ifdef MSDOS if(save_name[1]==':') save_name+=2;#endif while(*save_name=='/') save_name++; strcpy(real_s_name,save_name); real_s_totsize = save_totsize; real_s_sizeleft = save_sizeleft; } return; } /* We're multivol Panic if we didn't get the right kind of response */ /* ENXIO is for the UNIX PC */ if(err>0 || (err<0 && errno!=ENOSPC && errno!=EIO && errno!=ENXIO)) writeerror(err); if(new_volume(0)<0) return;#ifdef TEST test_written=0;#endif if(f_volhdr && real_s_name[0]) { copy_back=2; ar_block-=2; } else if(f_volhdr || real_s_name[0]) { copy_back = 1; ar_block--; } else copy_back = 0; if(f_volhdr) { bzero((void *)ar_block,RECORDSIZE); sprintf(ar_block->header.name,"%s Volume %d",f_volhdr,volno); to_oct(time(0), 1+12, ar_block->header.mtime); ar_block->header.linkflag = LF_VOLHDR; finish_header(ar_block); } if(real_s_name[0]) { int tmp; if(f_volhdr) ar_block++; bzero((void *)ar_block,RECORDSIZE); strcpy(ar_block->header.name,real_s_name); ar_block->header.linkflag = LF_MULTIVOL; to_oct((long)real_s_sizeleft,1+12, ar_block->header.size); to_oct((long)real_s_totsize-real_s_sizeleft, 1+12,ar_block->header.offset); tmp=f_verbose; f_verbose=0; finish_header(ar_block); f_verbose=tmp; if(f_volhdr) ar_block--; } err = rmtwrite(archive, ar_block->charptr,(int) blocksize); if(err!=blocksize) writeerror(err);#ifdef TEST test_written = blocksize;#endif if(copy_back) { ar_block+=copy_back; bcopy((void *)(ar_block+blocking-copy_back), (void *)ar_record, copy_back*RECORDSIZE); ar_record+=copy_back; if(real_s_sizeleft>=copy_back*RECORDSIZE) real_s_sizeleft-=copy_back*RECORDSIZE; else if((real_s_sizeleft+RECORDSIZE-1)/RECORDSIZE<=copy_back) real_s_name[0] = '\0'; else {#ifdef MSDOS if(save_name[1]==':') save_name+=2;#endif while(*save_name=='/') save_name++; strcpy(real_s_name,save_name); real_s_sizeleft = save_sizeleft; real_s_totsize=save_totsize; } copy_back = 0; }}/* Handle write errors on the archive. Write errors are always fatal *//* Hitting the end of a volume does not cause a write error unless the write* was the first block of the volume */voidwriteerror(err)int err;{ if (err < 0) { msg_perror("can't write to %s",ar_file); exit(EX_BADARCH); } else { msg("only wrote %u of %u bytes to %s",err,blocksize,ar_file); exit(EX_BADARCH); }}/* * Handle read errors on the archive. * * If the read should be retried, readerror() returns to the caller. */voidreaderror(){# define READ_ERROR_MAX 10 read_error_flag++; /* Tell callers */ msg_perror("read error on %s",ar_file); if (baserec == 0) { /* First block of tape. Probably stupidity error */ exit(EX_BADARCH); } /* * Read error in mid archive. We retry up to READ_ERROR_MAX times * and then give up on reading the archive. We set read_error_flag * for our callers, so they can cope if they want. */ if (r_error_count++ > READ_ERROR_MAX) { msg("Too many errors, quitting."); exit(EX_BADARCH); } return;}/* * Perform a read to flush the buffer. */fl_read(){ int err; /* Result from system call */ int left; /* Bytes left */ char *more; /* Pointer to next byte to read */ /* * Clear the count of errors. This only applies to a single * call to fl_read. We leave read_error_flag alone; it is * only turned off by higher level software. */ r_error_count = 0; /* Clear error count */ /* * If we are about to wipe out a record that * somebody needs to keep, copy it out to a holding * area and adjust somebody's pointer to it. */ if (save_rec && *save_rec >= ar_record && *save_rec < ar_last) { record_save_area = **save_rec; *save_rec = &record_save_area; } if(write_archive_to_stdout && baserec!=0) { err=rmtwrite(1, ar_block->charptr, blocksize); if(err!=blocksize) writeerror(err); } if(f_multivol) { if(save_name) { if(save_name!=real_s_name) {#ifdef MSDOS if(save_name[1]==':') save_name+=2;#endif while(*save_name=='/') save_name++; strcpy(real_s_name,save_name); save_name=real_s_name; } real_s_totsize = save_totsize; real_s_sizeleft = save_sizeleft; } else { real_s_name[0]='\0'; real_s_totsize=0; real_s_sizeleft = 0; } }error_loop: err = rmtread(archive, ar_block->charptr, (int)blocksize); if (err == blocksize) return; if((err == 0 || (err<0 && errno==ENOSPC)) && f_multivol) { union record *head; try_volume: if(new_volume((cmd_mode==CMD_APPEND || cmd_mode==CMD_CAT || cmd_mode==CMD_UPDATE) ? 2 : 1)<0) return; vol_error: err = rmtread(archive, ar_block->charptr,(int) blocksize); if(err < 0) { readerror(); goto vol_error; } if(err!=blocksize) goto short_read; head=ar_block; if(head->header.linkflag==LF_VOLHDR) { if(f_volhdr) { char *ptr; ptr=(char *)malloc(strlen(f_volhdr)+20); sprintf(ptr,"%s Volume %d",f_volhdr,volno); if(strcmp(ptr,head->header.name)) { msg("Volume mismatch! %s!=%s\n",ptr,head->header.name); --volno; free(ptr); goto try_volume; } free(ptr); } if(f_verbose) fprintf(msg_file,"Reading %s\n",head->header.name); head++; } else if(f_volhdr) { msg("Warning: No volume header!"); } if(real_s_name[0]) { long from_oct(); if(head->header.linkflag!=LF_MULTIVOL || strcmp(head->header.name,real_s_name)) { msg("%s is not continued on this volume!",real_s_name); --volno; goto try_volume; } if(real_s_totsize!=from_oct(1+12,head->header.size)+from_oct(1+12,head->header.offset)) { msg("%s is the wrong size (%ld!=%ld+%ld)", head->header.name,save_totsize, from_oct(1+12,head->header.size), from_oct(1+12,head->header.offset)); --volno; goto try_volume; } if(real_s_totsize-real_s_sizeleft!=from_oct(1+12,head->header.offset)) { msg("This volume is out of sequence"); --volno; goto try_volume; } head++; } ar_record=head; return; } else if (err < 0) { readerror(); goto error_loop; /* Try again */ } short_read: more = ar_block->charptr + err; left = blocksize - err;again: if (0 == (((unsigned)left) % RECORDSIZE)) { /* FIXME, for size=0, multi vol support */ /* On the first block, warn about the problem */ if (!f_reblock && baserec == 0 && f_verbose && err > 0) { /* msg("Blocksize = %d record%s", err / RECORDSIZE, (err > RECORDSIZE)? "s": "");*/ msg("Blocksize = %d records", err / RECORDSIZE); } ar_last = ar_block + ((unsigned)(blocksize - left))/RECORDSIZE; return; } if (f_reblock) { /* * User warned us about this. Fix up. */ if (left > 0) {error2loop: err = rmtread(archive, more, (int)left); if (err < 0) { readerror(); goto error2loop; /* Try again */ } if (err == 0) { msg("archive %s EOF not on block boundary",ar_file); exit(EX_BADARCH); } left -= err; more += err; goto again; } } else { msg("only read %d bytes from archive %s",err,ar_file); exit(EX_BADARCH); }}/* * Flush the current buffer to/from the archive. */flush_archive(){ int c; baserec += ar_last - ar_block; /* Keep track of block #s */ ar_record = ar_block; /* Restore pointer to start */ ar_last = ar_block + blocking; /* Restore pointer to end */ if (ar_reading) { if(time_to_start_writing) { time_to_start_writing=0; ar_reading=0; if(file_to_switch_to>=0) { if((c=rmtclose(archive))<0) msg_perror("Warning: can't close %s(%d,%d)",ar_file,archive,c); archive=file_to_switch_to; } else (void)backspace_output(); fl_write(); } else fl_read(); } else { fl_write(); }}/* Backspace the archive descriptor by one blocks worth. If its a tape, MTIOCTOP will work. If its something else, we try to seek on it. If we can't seek, we lose! */backspace_output(){ long cur; /* int er; */ extern char *output_start;#ifdef MTIOCTOP struct mtop t; t.mt_op = MTBSR; t.mt_count = 1; if((rmtioctl(archive,MTIOCTOP,&t))>=0) return 1; if(errno==EIO && (rmtioctl(archive,MTIOCTOP,&t))>=0) return 1;#endif cur=rmtlseek(archive,0L,1); cur-=blocksize; /* Seek back to the beginning of this block and start writing there. */ if(rmtlseek(archive,cur,0)!=cur) { /* Lseek failed. Try a different method */ msg("Couldn't backspace archive file. It may be unreadable without -i."); /* Replace the first part of the block with nulls */ if(ar_block->charptr!=output_start) bzero(ar_block->charptr,output_start-ar_block->charptr); return 2; } return 3;}/* * Close the archive file. */close_archive(){ int child; int status; int c; if (time_to_start_writing || !ar_reading) flush_archive(); if(cmd_mode==CMD_DELETE) { long pos; pos = rmtlseek(archive,0L,1);#ifndef MSDOS /* FIXME does ftruncate really take an INT?! */ (void) ftruncate(archive,(int)pos);#else (void)rmtwrite(archive,"",0);#endif } if(f_verify) verify_volume(); if((c=rmtclose(archive))<0) msg_perror("Warning: can't close %s(%d,%d)",ar_file,archive,c);#ifndef MSDOS if (childpid) { /* * Loop waiting for the right child to die, or for * no more kids. */ while (((child = wait(&status)) != childpid) && child != -1) ; if (child != -1) { switch (TERM_SIGNAL(status)) { case 0: /* Child voluntarily terminated -- but why? */ if (TERM_VALUE(status) == MAGIC_STAT) { exit(EX_SYSTEM);/* Child had trouble */ } if (TERM_VALUE(status) == (SIGPIPE + 128)) { /* * /bin/sh returns this if its child * dies with SIGPIPE. 'Sok. */ break; } else if (TERM_VALUE(status)) msg("child returned status %d", TERM_VALUE(status)); case SIGPIPE: break; /* This is OK. */ default: msg("child died with signal %d%s", TERM_SIGNAL(status), TERM_COREDUMP(status)? " (core dumped)": ""); } } }#endif /* MSDOS */}#ifdef DONTDEF/* * Message management. * * anno writes a message prefix on stream (eg stdout, stderr). * * The specified prefix is normally output followed by a colon and a space. * However, if other command line options are set, more output can come * out, such as the record # within the archive. * * If the specified prefix is NULL, no output is produced unless the * command line option(s) are set. * * If the third argument is 1, the "saved" record # is used; if 0, the * "current" record # is used. */voidanno(stream, prefix, savedp) FILE *stream; char *prefix; int savedp;{# define MAXANNO 50 char buffer[MAXANNO]; /* Holds annorecment */# define ANNOWIDTH 13 int space; long offset; int save_e; save_e=errno; /* Make sure previous output gets out in sequence */ if (stream == stderr) fflush(stdout); if (f_sayblock) { if (prefix) { fputs(prefix, stream); putc(' ', stream); } offset = ar_record - ar_block; (void) sprintf(buffer, "rec %d: ", savedp? saved_recno: baserec + offset); fputs(buffer, stream); space = ANNOWIDTH - strlen(buffer); if (space > 0) { fprintf(stream, "%*s", space, ""); } } else if (prefix) { fputs(prefix, stream); fputs(": ", stream); } errno=save_e;}#endif/* We've hit the end of the old volume. Close it and open the next one *//* Values for type: 0: writing 1: reading 2: updating */new_volume(type)int type;{ int c; char inbuf[80]; char *p; static FILE *read_file = 0; extern int now_verifying; extern char TTY_NAME[]; char *getenv(); if(!read_file && !f_run_script_at_end) read_file = (archive==0) ? fopen(TTY_NAME, "r") : stdin; if(now_verifying) return -1; if(f_verify) verify_volume(); if((c=rmtclose(archive))<0) msg_perror("Warning: can't close %s(%d,%d)",ar_file,archive,c); volno++; tryagain: if (f_run_script_at_end) system(info_script); else for(;;) { fprintf(msg_file,"Prepare volume #%d and hit return: ",volno); if(fgets(inbuf,sizeof(inbuf),read_file)==0 || inbuf[0]=='\n') break; switch(inbuf[0]) { case '?': { fprintf(msg_file,"\ n [name] Give a new filename for the next (and subsequent) volume(s)\n\ q Abort tar\n\ ! Spawn a subshell\n\ ? Print this list\n"); } break; case 'q': /* Quit */ fprintf(msg_file,"No new volume; exiting.\n"); if(cmd_mode!=CMD_EXTRACT && cmd_mode!=CMD_LIST && cmd_mode!=CMD_DIFF) msg("Warning: Archive is INCOMPLETE!"); exit(EX_BADARCH); case 'n': /* Get new file name */ { char *q,*r; static char *old_name; for(q= &inbuf[1];*q==' ' || *q=='\t';q++) ; for(r=q;*r;r++) if(*r=='\n') *r='\0'; if(old_name) free(old_name); old_name=p=(char *)malloc((unsigned)(strlen(q)+2)); if(p==0) { msg("Can't allocate memory for name"); exit(EX_SYSTEM); } (void) strcpy(p,q); ar_file=p; } break; case '!':#ifdef MSDOS spawnl(P_WAIT,getenv("COMSPEC"),"-",0);#else /* JF this needs work! */ switch(fork()) { case -1: msg_perror("can't fork!"); break; case 0: p=getenv("SHELL"); if(p==0) p="/bin/sh"; execlp(p,"-sh","-i",0); msg_perror("can't exec a shell %s",p); _exit(55); default: wait(0); break; }#endif break; } } if(type==2 || f_verify) archive=rmtopen(ar_file,O_RDWR|O_CREAT,0666); else if(type==1) archive=rmtopen(ar_file,O_RDONLY,0666); else if(type==0) archive=rmtcreat(ar_file,0666); else archive= -1; if(archive<0) { msg_perror("can't open %s",ar_file); goto tryagain; }#ifdef MSDOS setmode(archive,O_BINARY);#endif return 0;}/* this is a useless function that takes a buffer returned by wantbytes and does nothing with it. If the function called by wantbytes returns an error indicator (non-zero), this function is called for the rest of the file. */intno_op(size,data)int size;char *data;{ return 0;}/* Some other routine wants SIZE bytes in the archive. For each chunk of the archive, call FUNC with the size of the chunk, and the address of the chunk it can work with. */intwantbytes(size,func)long size;int (*func)();{ char *data; long data_size; while(size) { data = findrec()->charptr; if (data == NULL) { /* Check it... */ msg("Unexpected EOF on archive file"); return -1; } data_size = endofrecs()->charptr - data; if(data_size>size) data_size=size; if((*func)(data_size,data)) func=no_op; userec((union record *)(data + data_size - 1)); size-=data_size; } return 0;}
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