Annotation of researchv10no/cmd/post.src/postreverse/postreverse.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  *
                      3:  * postreverse - reverse the page order in certain PostScript files.
                      4:  *
                      5:  * Page reversal relies on being able to locate sections of a document using file
                      6:  * structuring comments defined by Adobe (ie. the 1.0 and now 2.0 conventions) and
                      7:  * a few I've added. Among other things a minimally conforming document, according
                      8:  * to the 1.0 conventions,
                      9:  *
                     10:  *     1) Marks the end of the prologue with an %%EndProlog comment.
                     11:  *
                     12:  *     2) Starts each page with a %%Page: comment.
                     13:  *
                     14:  *     3) Marks the end of all the pages %%Trailer comment.
                     15:  *
                     16:  *     4) Obeys page independence (ie. pages can be arbitrarily rearranged).
                     17:  *
                     18:  * The most important change (at least for this program) that Adobe made in going
                     19:  * from the 1.0 to the 2.0 structuring conventions was in the prologue. They now
                     20:  * say the prologue should only define things, and the global initialization that
                     21:  * was in the prologue (1.0 conventions) should now come after the %%EndProlog
                     22:  * comment but before the first %%Page: comment and be bracketed by %%BeginSetup
                     23:  * and %%EndSetup comments. So a document that conforms to Adobe's 2.0 conventions,
                     24:  *
                     25:  *     1) Marks the end of the prologue (only definitions) with %%EndProlog.
                     26:  *
                     27:  *     2) Brackets global initialization with %%BeginSetup and %%EndSetup comments
                     28:  *        which come after the prologue but before the first %Page: comment.
                     29:  *
                     30:  *     3) Starts each page with a %%Page: comment.
                     31:  *
                     32:  *     4) Marks the end of all the pages with a %%Trailer comment.
                     33:  *
                     34:  *     5) Obeys page independence.
                     35:  *
                     36:  * postreverse can handle documents that follow the 1.0 or 2.0 conventions, but has
                     37:  * also been extended slightly so it works properly with the translators (primarily
                     38:  * dpost) supplied with this package. The page independence requirement has been
                     39:  * relaxed some. In particular definitions exported to the global environment from
                     40:  * within a page should be bracketed by %%BeginGlobal and %%EndGlobal comments.
                     41:  * postreverse pulls them out of each page and inserts them in the setup section
                     42:  * of the document, immediately before it writes the %%EndProlog (for version 1.0)
                     43:  * or %%EndSetup (for version 2.0) comments.
                     44:  *
                     45:  * In addition postreverse accepts documents that choose to mark the end of each
                     46:  * page with a %%EndPage: comment, which from a translator's point of view is often
                     47:  * a more natural approach. Both page boundary comments (ie. Page: and %%EndPage:)
                     48:  * are also accepted, but be warned that everything between consecutive %%EndPage:
                     49:  * and %%Page: comments will be ignored.
                     50:  *
                     51:  * So a document that will reverse properly with postreverse,
                     52:  *
                     53:  *     1) Marks the end of the prologue with %%EndProlog.
                     54:  *
                     55:  *     2) May have a %%BeginSetup/%%EndSetup comment pair before the first %%Page:
                     56:  *        comment that brackets any global initialization.
                     57:  *
                     58:  *     3) Marks the start of each page with a %%Page: comment, or the end of each
                     59:  *        page with a %%EndPage: comment. Both page boundary comments are allowed.
                     60:  *
                     61:  *     4) Marks the end of all the pages with a %%Trailer comment.
                     62:  *
                     63:  *     5) Obeys page independence or violates it to a rather limited extent and
                     64:  *        marks the violations with %%BeginGlobal and %%EndGlobal comments.
                     65:  *
                     66:  * If no file arguments are given postreverse copies stdin to a temporary file and
                     67:  * then processes that file. That means the input is read three times (rather than
                     68:  * two) whenever we handle stdin. That's expensive, and shouldn't be too difficult
                     69:  * to fix, but I haven't gotten around to it yet.
                     70:  *
                     71:  */
                     72: 
                     73: #include <stdio.h>
                     74: #include <signal.h>
                     75: #include <fcntl.h>
                     76: 
                     77: #include "comments.h"                  /* PostScript file structuring comments */
                     78: #include "gen.h"                       /* general purpose definitions */
                     79: #include "path.h"                      /* for temporary directory */
                     80: #include "ext.h"                       /* external variable declarations */
                     81: #include "postreverse.h"               /* a few special definitions */
                     82: 
                     83: int    page = 1;                       /* current page number */
                     84: int    forms = 1;                      /* forms per page in the input file */
                     85: 
                     86: char   *temp_dir = TEMPDIR;            /* temp directory for copying stdin */
                     87: 
                     88: Pages  pages[1000];                    /* byte offsets for all pages */
                     89: int    next_page = 0;                  /* next page goes here */
                     90: long   start;                          /* starting offset for next page */
                     91: long   endoff = -1;                    /* offset where TRAILER was found */
                     92: int    noreverse = FALSE;              /* don't reverse pages if TRUE */
                     93: char   *endprolog = ENDPROLOG;         /* occasionally changed to ENDSETUP */
                     94: 
                     95: double version = 3.3;                  /* of the input file */
                     96: int    ignoreversion = FALSE;          /* ignore possible forms.ps problems */
                     97: 
                     98: char   buf[2048];                      /* line buffer for input file */
                     99: 
                    100: FILE   *fp_in;                         /* stuff is read from this file */
                    101: FILE   *fp_out = stdout;               /* and written here */
                    102: 
                    103: /*****************************************************************************/
                    104: 
                    105: main(agc, agv)
                    106: 
                    107:     int                agc;
                    108:     char       *agv[];
                    109: 
                    110: {
                    111: 
                    112: /*
                    113:  *
                    114:  * A simple program that reverses the pages in specially formatted PostScript
                    115:  * files. Will work with all the translators in this package, and should handle
                    116:  * any document that conforms to Adobe's version 1.0 or 2.0 file structuring
                    117:  * conventions. Only one input file is allowed, and it can either be a named (on
                    118:  * the command line) file or stdin.
                    119:  *
                    120:  */
                    121: 
                    122:     argc = agc;                                /* other routines may want them */
                    123:     argv = agv;
                    124: 
                    125:     prog_name = argv[0];               /* just for error messages */
                    126: 
                    127:     init_signals();                    /* sets up interrupt handling */
                    128:     options();                         /* first get command line options */
                    129:     arguments();                       /* then process non-option arguments */
                    130:     done();                            /* and clean things up */
                    131: 
                    132:     exit(x_stat);                      /* not much could be wrong */
                    133: 
                    134: }   /* End of main */
                    135: 
                    136: /*****************************************************************************/
                    137: 
                    138: init_signals()
                    139: 
                    140: {
                    141: 
                    142: /*
                    143:  *
                    144:  * Makes sure we handle interrupts properly.
                    145:  *
                    146:  */
                    147: 
                    148:     if ( signal(SIGINT, interrupt) == SIG_IGN )  {
                    149:        signal(SIGINT, SIG_IGN);
                    150:        signal(SIGQUIT, SIG_IGN);
                    151:        signal(SIGHUP, SIG_IGN);
                    152:     } else {
                    153:        signal(SIGHUP, interrupt);
                    154:        signal(SIGQUIT, interrupt);
                    155:     }   /* End else */
                    156: 
                    157:     signal(SIGTERM, interrupt);
                    158: 
                    159: }   /* End of init_signals */
                    160: 
                    161: /*****************************************************************************/
                    162: 
                    163: options()
                    164: 
                    165: {
                    166: 
                    167:     int                ch;                     /* return value from getopt() */
                    168:     char       *optnames = "n:o:rvT:DI";
                    169: 
                    170:     extern char        *optarg;                /* used by getopt() */
                    171:     extern int optind;
                    172: 
                    173: /*
                    174:  *
                    175:  * Reads and processes the command line options. The -r option (ie. the one that
                    176:  * turns page reversal off) is really only useful if you want to take dpost output
                    177:  * and produce a page independent output file. In that case global definitions
                    178:  * made within pages and bracketed by %%BeginGlobal/%%EndGlobal comments will be
                    179:  * moved into the prologue or setup section of the document.
                    180:  *
                    181:  */
                    182: 
                    183:     while ( (ch = getopt(argc, argv, optnames)) != EOF )  {
                    184:        switch ( ch )  {
                    185:            case 'n':                   /* forms per page */
                    186:                    if ( (forms = atoi(optarg)) <= 0 )
                    187:                        error(FATAL, "illegal forms request %s", optarg);
                    188:                    break;
                    189: 
                    190:            case 'o':                   /* output page list */
                    191:                    out_list(optarg);
                    192:                    break;
                    193: 
                    194:            case 'r':                   /* don't reverse the pages */
                    195:                    noreverse = TRUE;
                    196:                    break;
                    197: 
                    198:            case 'v':                   /* ignore possible forms.ps problems */
                    199:                    ignoreversion = TRUE;
                    200:                    break;
                    201: 
                    202:            case 'T':                   /* temporary file directory */
                    203:                    temp_dir = optarg;
                    204:                    break;
                    205: 
                    206:            case 'D':                   /* debug flag */
                    207:                    debug = ON;
                    208:                    break;
                    209: 
                    210:            case 'I':                   /* ignore FATAL errors */
                    211:                    ignore = ON;
                    212:                    break;
                    213: 
                    214:            case '?':                   /* don't understand the option */
                    215:                    error(FATAL, "");
                    216:                    break;
                    217: 
                    218:            default:                    /* don't know what to do for ch */
                    219:                    error(FATAL, "missing case for option %c\n", ch);
                    220:                    break;
                    221:        }   /* End switch */
                    222:     }   /* End while */
                    223: 
                    224:     argc -= optind;                    /* get ready for non-option args */
                    225:     argv += optind;
                    226: 
                    227: }   /* End of options */
                    228: 
                    229: /*****************************************************************************/
                    230: 
                    231: arguments()
                    232: 
                    233: {
                    234: 
                    235:     char       *name;                  /* name of the input file */
                    236: 
                    237: /*
                    238:  *
                    239:  * postreverse only handles one input file at a time, so if there's more than one
                    240:  * argument left when we get here we'll quit. If none remain we copy stdin to a
                    241:  * temporary file and process that file.
                    242:  *
                    243:  */
                    244: 
                    245:     if ( argc > 1 )                    /* can't handle more than one file */
                    246:        error(FATAL, "too many arguments");
                    247: 
                    248:     if ( argc == 0 )                   /* copy stdin to a temporary file */
                    249:        name = copystdin();
                    250:     else name = *argv;
                    251: 
                    252:     if ( (fp_in = fopen(name, "r")) == NULL )
                    253:        error(FATAL, "can't open %s", name);
                    254: 
                    255:     reverse();
                    256: 
                    257: }   /* End of arguments */
                    258: 
                    259: /*****************************************************************************/
                    260: 
                    261: done()
                    262: 
                    263: {
                    264: 
                    265: /*
                    266:  *
                    267:  * Cleans things up after we've finished reversing the pages in the input file.
                    268:  * All that's really left to do is remove the temp file, provided we used one.
                    269:  *
                    270:  */
                    271: 
                    272:     if ( temp_file != NULL )
                    273:        unlink(temp_file);
                    274: 
                    275: }   /* End of done */
                    276: 
                    277: /*****************************************************************************/
                    278: 
                    279: char *copystdin()
                    280: 
                    281: {
                    282: 
                    283:     int                fd_out;                 /* for the temporary file */
                    284:     int                fd_in;                  /* for stdin */
                    285:     int                count;                  /* number of bytes put in buf[] */
                    286: 
                    287: /*
                    288:  *
                    289:  * Copies stdin to a temporary file and returns the pathname of that file to the
                    290:  * caller. It's an expensive way of doing things, because it means we end up
                    291:  * reading the input file three times - rather than just twice. Could probably be
                    292:  * fixed by creating the temporary file on the fly as we read the file the first
                    293:  * time.
                    294:  *
                    295:  */
                    296: 
                    297:     if ( (temp_file = tempnam(temp_dir, "post")) == NULL )
                    298:        error(FATAL, "can't generate temp file name");
                    299: 
                    300:     if ( (fd_out = creat(temp_file, 0660)) == -1 )
                    301:        error(FATAL, "can't open %s", temp_file);
                    302: 
                    303:     fd_in = fileno(stdin);
                    304: 
                    305:     while ( (count = read(fd_in, buf, sizeof(buf))) > 0 )
                    306:        if ( write(fd_out, buf, count) != count )
                    307:            error(FATAL, "error writing to %s", temp_file);
                    308: 
                    309:     close(fd_out);
                    310: 
                    311:     return(temp_file);
                    312: 
                    313: }   /* End of copystdin */
                    314: 
                    315: /*****************************************************************************/
                    316: 
                    317: reverse()
                    318: 
                    319: {
                    320: 
                    321: /*
                    322:  *
                    323:  * Begins by looking for the ENDPROLOG comment in the input file. Everything up to
                    324:  * that comment is copied to the output file. If the comment isn't found the entire
                    325:  * input file is copied and moreprolog() returns FALSE. Otherwise readpages() reads
                    326:  * the rest of the input file and remembers (in pages[]) where each page starts and
                    327:  * ends. In addition everything bracketed by %%BeginGlobal and %%EndGlobal comments
                    328:  * is immediately added to the new prologue (or setup section) and ends up being
                    329:  * removed from the individual pages. When readpages() finds the TRAILER comment
                    330:  * or gets to the end of the input file we go back to the pages[] array and use
                    331:  * the saved offsets to write the pages out in reverse order. Finally everything
                    332:  * from the TRAILER comment to the end of the input file is copied to the output
                    333:  * file.
                    334:  *
                    335:  */
                    336: 
                    337:     if ( moreprolog(ENDPROLOG) == TRUE )  {
                    338:        readpages();
                    339:        writepages();
                    340:        trailer();
                    341:     }  /* End if */
                    342: 
                    343: }   /* End of reverse */
                    344: 
                    345: /*****************************************************************************/
                    346: 
                    347: moreprolog(str)
                    348: 
                    349:     char       *str;                   /* copy everything up to this string */
                    350: 
                    351: {
                    352: 
                    353:     int                len;                    /* length of FORMSPERPAGE string */
                    354:     int                vlen;                   /* length of VERSION string */
                    355: 
                    356: /*
                    357:  *
                    358:  * Looks for string *str at the start of a line and copies everything up to that
                    359:  * string to the output file. If *str isn't found the entire input file will end
                    360:  * up being copied to the output file and FALSE will be returned to the caller.
                    361:  * The first call (made from reverse()) looks for ENDPROLOG. Any other call comes
                    362:  * from readpages() and will be looking for the ENDSETUP comment.
                    363:  * 
                    364:  */
                    365: 
                    366:     len = strlen(FORMSPERPAGE);
                    367:     vlen = strlen(VERSION);
                    368: 
                    369:     while ( fgets(buf, sizeof(buf), fp_in) != NULL )  {
                    370:        if ( strcmp(buf, str) == 0 )
                    371:            return(TRUE);
                    372:        else if ( strncmp(buf, FORMSPERPAGE, len) == 0 )
                    373:            forms = atoi(&buf[len+1]);
                    374:        else if ( strncmp(buf, VERSION, vlen) == 0 )
                    375:            version = atof(&buf[vlen+1]);
                    376:        fprintf(fp_out, "%s", buf);
                    377:     }  /* End while */
                    378: 
                    379:     return(FALSE);
                    380: 
                    381: }   /* End of moreprolog */
                    382: 
                    383: /*****************************************************************************/
                    384: 
                    385: readpages()
                    386: 
                    387: {
                    388: 
                    389:     int                endpagelen;             /* length of ENDPAGE */
                    390:     int                pagelen;                /* and PAGE strings */
                    391:     int                sawendpage = TRUE;      /* ENDPAGE equivalent marked last page */
                    392:     int                gotpage = FALSE;        /* TRUE disables BEGINSETUP stuff */
                    393: 
                    394: /*
                    395:  *
                    396:  * Records starting and ending positions of the requested pages (usually all of
                    397:  * them), puts global definitions in the prologue, and remembers where the TRAILER
                    398:  * was found.
                    399:  *
                    400:  * Page boundaries are marked by the strings PAGE, ENDPAGE, or perhaps both.
                    401:  * Application programs will normally find one or the other more convenient, so
                    402:  * in most cases only one kind of page delimiter will be found in a particular
                    403:  * document.
                    404:  *
                    405:  */
                    406: 
                    407:     pages[0].start = ftell(fp_in);     /* first page starts after ENDPROLOG */
                    408:     endprolog = ENDPROLOG;
                    409: 
                    410:     endpagelen = strlen(ENDPAGE);
                    411:     pagelen = strlen(PAGE);
                    412: 
                    413:     while ( fgets(buf, sizeof(buf), fp_in) != NULL )
                    414:        if ( buf[0] != '%' )
                    415:            continue;
                    416:        else if ( strncmp(buf, ENDPAGE, endpagelen) == 0 )  {
                    417:            if ( in_olist(page++) == ON )  {
                    418:                pages[next_page].empty = FALSE;
                    419:                pages[next_page++].stop = ftell(fp_in);
                    420:            }   /* End if */
                    421:            pages[next_page].start = ftell(fp_in);
                    422:            sawendpage = TRUE;
                    423:            gotpage = TRUE;
                    424:        } else if ( strncmp(buf, PAGE, pagelen) == 0 )  {
                    425:            if ( sawendpage == FALSE && in_olist(page++) == ON )  {
                    426:                pages[next_page].empty = FALSE;
                    427:                pages[next_page++].stop = ftell(fp_in) - strlen(buf);
                    428:            }   /* End if */
                    429:            pages[next_page].start = ftell(fp_in) - strlen(buf);
                    430:            sawendpage = FALSE;
                    431:            gotpage = TRUE;
                    432:        } else if ( gotpage == FALSE && strcmp(buf, BEGINSETUP) == 0 )  {
                    433:            fprintf(fp_out, "%s", endprolog);
                    434:            fprintf(fp_out, "%s", BEGINSETUP);
                    435:            moreprolog(ENDSETUP);
                    436:            endprolog = ENDSETUP;
                    437:        } else if ( strcmp(buf, BEGINGLOBAL) == 0 )  {
                    438:            moreprolog(ENDGLOBAL);
                    439:        } else if ( strcmp(buf, TRAILER) == 0 )  {
                    440:            if ( sawendpage == FALSE )
                    441:                pages[next_page++].stop = ftell(fp_in) - strlen(buf);
                    442:            endoff = ftell(fp_in);
                    443:            break;
                    444:        }   /* End if */
                    445: 
                    446: }   /* End of readpages */
                    447: 
                    448: /*****************************************************************************/
                    449: 
                    450: writepages()
                    451: 
                    452: {
                    453: 
                    454:     int                i, j, k;                /* loop indices */
                    455: 
                    456: /*
                    457:  *
                    458:  * Goes through the pages[] array, usually from the bottom up, and writes out all
                    459:  * the pages. Documents that print more than one form per page cause things to get
                    460:  * a little more complicated. Each physical page has to have its subpages printed
                    461:  * in the correct order, and we have to build a few dummy subpages for the last
                    462:  * (and now first) sheet of paper, otherwise things will only occasionally work.
                    463:  *
                    464:  */
                    465: 
                    466:     fprintf(fp_out, "%s", endprolog);
                    467: 
                    468:     if ( noreverse == FALSE )          /* fill out the first page */
                    469:        for ( i = (forms - next_page % forms) % forms; i > 0; i--, next_page++ )
                    470:            pages[next_page].empty = TRUE;
                    471:     else forms = next_page;            /* turns reversal off in next loop */
                    472: 
                    473:     for ( i = next_page - forms; i >= 0; i -= forms )
                    474:        for ( j = i, k = 0; k < forms; j++, k++ )
                    475:            if ( pages[j].empty == TRUE ) {
                    476:                if ( ignoreversion == TRUE || version > 3.1 ) {
                    477:                    fprintf(fp_out, "%s 0 0\n", PAGE);
                    478:                    fprintf(fp_out, "/saveobj save def\n");
                    479:                    fprintf(fp_out, "showpage\n");
                    480:                    fprintf(fp_out, "saveobj restore\n");
                    481:                    fprintf(fp_out, "%s 0 0\n", ENDPAGE);
                    482:                } else {
                    483:                    fprintf(fp_out, "%s 0 0\n", PAGE);
                    484:                    fprintf(fp_out, "save showpage restore\n");
                    485:                    fprintf(fp_out, "%s 0 0\n", ENDPAGE);
                    486:                }   /* End else */
                    487:            } else copypage(pages[j].start, pages[j].stop);
                    488: 
                    489: }   /* End of writepages */
                    490: 
                    491: /*****************************************************************************/
                    492: 
                    493: copypage(start, stop)
                    494: 
                    495:     long       start;                  /* starting from this offset */
                    496:     long       stop;                   /* and ending here */
                    497: 
                    498: {
                    499: 
                    500: /*
                    501:  *
                    502:  * Copies the page beginning at offset start and ending at stop to the output
                    503:  * file. Global definitions are skipped since they've already been added to the
                    504:  * prologue.
                    505:  *
                    506:  */
                    507: 
                    508:     fseek(fp_in, start, 0);
                    509: 
                    510:     while ( ftell(fp_in) < stop && fgets(buf, sizeof(buf), fp_in) != NULL )
                    511:        if ( buf[0] == '%' && strcmp(buf, BEGINGLOBAL) == 0 )
                    512:            while ( fgets(buf, sizeof(buf), fp_in) != NULL && strcmp(buf, ENDGLOBAL) != 0 ) ;
                    513:        else fprintf(fp_out, "%s", buf);
                    514: 
                    515: }   /* End of copypage */
                    516: 
                    517: /*****************************************************************************/
                    518: 
                    519: trailer()
                    520: 
                    521: {
                    522: 
                    523: /*
                    524:  *
                    525:  * Makes sure everything from the TRAILER string to EOF is copied to the output
                    526:  * file.
                    527:  *
                    528:  */
                    529: 
                    530:     if ( endoff > 0 )  {
                    531:        fprintf(fp_out, "%s", TRAILER);
                    532:        fseek(fp_in, endoff, 0);
                    533:        while ( fgets(buf, sizeof(buf), fp_in) != NULL )
                    534:            fprintf(fp_out, "%s", buf);
                    535:     }  /* End if */
                    536: 
                    537: }   /* End of trailer */
                    538: 
                    539: /*****************************************************************************/
                    540: 

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