ref: c00c60d327168c25e56077c8310cf2380833e9be
dir: /sys/src/cmd/postscript/postreverse/postreverse.c/
/* * * postreverse - reverse the page order in certain PostScript files. * * Page reversal relies on being able to locate sections of a document using file * structuring comments defined by Adobe (ie. the 1.0 and now 2.0 conventions) and * a few I've added. Among other things a minimally conforming document, according * to the 1.0 conventions, * * 1) Marks the end of the prologue with an %%EndProlog comment. * * 2) Starts each page with a %%Page: comment. * * 3) Marks the end of all the pages %%Trailer comment. * * 4) Obeys page independence (ie. pages can be arbitrarily rearranged). * * The most important change (at least for this program) that Adobe made in going * from the 1.0 to the 2.0 structuring conventions was in the prologue. They now * say the prologue should only define things, and the global initialization that * was in the prologue (1.0 conventions) should now come after the %%EndProlog * comment but before the first %%Page: comment and be bracketed by %%BeginSetup * and %%EndSetup comments. So a document that conforms to Adobe's 2.0 conventions, * * 1) Marks the end of the prologue (only definitions) with %%EndProlog. * * 2) Brackets global initialization with %%BeginSetup and %%EndSetup comments * which come after the prologue but before the first %Page: comment. * * 3) Starts each page with a %%Page: comment. * * 4) Marks the end of all the pages with a %%Trailer comment. * * 5) Obeys page independence. * * postreverse can handle documents that follow the 1.0 or 2.0 conventions, but has * also been extended slightly so it works properly with the translators (primarily * dpost) supplied with this package. The page independence requirement has been * relaxed some. In particular definitions exported to the global environment from * within a page should be bracketed by %%BeginGlobal and %%EndGlobal comments. * postreverse pulls them out of each page and inserts them in the setup section * of the document, immediately before it writes the %%EndProlog (for version 1.0) * or %%EndSetup (for version 2.0) comments. * * In addition postreverse accepts documents that choose to mark the end of each * page with a %%EndPage: comment, which from a translator's point of view is often * a more natural approach. Both page boundary comments (ie. Page: and %%EndPage:) * are also accepted, but be warned that everything between consecutive %%EndPage: * and %%Page: comments will be ignored. * * So a document that will reverse properly with postreverse, * * 1) Marks the end of the prologue with %%EndProlog. * * 2) May have a %%BeginSetup/%%EndSetup comment pair before the first %%Page: * comment that brackets any global initialization. * * 3) Marks the start of each page with a %%Page: comment, or the end of each * page with a %%EndPage: comment. Both page boundary comments are allowed. * * 4) Marks the end of all the pages with a %%Trailer comment. * * 5) Obeys page independence or violates it to a rather limited extent and * marks the violations with %%BeginGlobal and %%EndGlobal comments. * * If no file arguments are given postreverse copies stdin to a temporary file and * then processes that file. That means the input is read three times (rather than * two) whenever we handle stdin. That's expensive, and shouldn't be too difficult * to fix, but I haven't gotten around to it yet. * */ #include <stdio.h> #include <signal.h> #include <sys/types.h> #include <fcntl.h> #include "comments.h" /* PostScript file structuring comments */ #include "gen.h" /* general purpose definitions */ #include "path.h" /* for temporary directory */ #include "ext.h" /* external variable declarations */ #include "postreverse.h" /* a few special definitions */ int page = 1; /* current page number */ int forms = 1; /* forms per page in the input file */ char *temp_dir = TEMPDIR; /* temp directory for copying stdin */ Pages pages[1000]; /* byte offsets for all pages */ int next_page = 0; /* next page goes here */ long start; /* starting offset for next page */ long endoff = -1; /* offset where TRAILER was found */ int noreverse = FALSE; /* don't reverse pages if TRUE */ char *endprolog = ENDPROLOG; /* occasionally changed to ENDSETUP */ double version = 3.3; /* of the input file */ int ignoreversion = FALSE; /* ignore possible forms.ps problems */ char buf[2048]; /* line buffer for input file */ FILE *fp_in; /* stuff is read from this file */ FILE *fp_out = stdout; /* and written here */ /*****************************************************************************/ main(agc, agv) int agc; char *agv[]; { /* * * A simple program that reverses the pages in specially formatted PostScript * files. Will work with all the translators in this package, and should handle * any document that conforms to Adobe's version 1.0 or 2.0 file structuring * conventions. Only one input file is allowed, and it can either be a named (on * the command line) file or stdin. * */ argc = agc; /* other routines may want them */ argv = agv; prog_name = argv[0]; /* just for error messages */ init_signals(); /* sets up interrupt handling */ options(); /* first get command line options */ arguments(); /* then process non-option arguments */ done(); /* and clean things up */ exit(x_stat); /* not much could be wrong */ } /* End of main */ /*****************************************************************************/ init_signals() { /* * * Makes sure we handle interrupts properly. * */ if ( signal(SIGINT, interrupt) == SIG_IGN ) { signal(SIGINT, SIG_IGN); signal(SIGQUIT, SIG_IGN); signal(SIGHUP, SIG_IGN); } else { signal(SIGHUP, interrupt); signal(SIGQUIT, interrupt); } /* End else */ signal(SIGTERM, interrupt); } /* End of init_signals */ /*****************************************************************************/ options() { int ch; /* return value from getopt() */ char *optnames = "n:o:rvT:DI"; extern char *optarg; /* used by getopt() */ extern int optind; /* * * Reads and processes the command line options. The -r option (ie. the one that * turns page reversal off) is really only useful if you want to take dpost output * and produce a page independent output file. In that case global definitions * made within pages and bracketed by %%BeginGlobal/%%EndGlobal comments will be * moved into the prologue or setup section of the document. * */ while ( (ch = getopt(argc, argv, optnames)) != EOF ) { switch ( ch ) { case 'n': /* forms per page */ if ( (forms = atoi(optarg)) <= 0 ) error(FATAL, "illegal forms request %s", optarg); break; case 'o': /* output page list */ out_list(optarg); break; case 'r': /* don't reverse the pages */ noreverse = TRUE; break; case 'v': /* ignore possible forms.ps problems */ ignoreversion = TRUE; break; case 'T': /* temporary file directory */ temp_dir = optarg; break; case 'D': /* debug flag */ debug = ON; break; case 'I': /* ignore FATAL errors */ ignore = ON; break; case '?': /* don't understand the option */ error(FATAL, ""); break; default: /* don't know what to do for ch */ error(FATAL, "missing case for option %c\n", ch); break; } /* End switch */ } /* End while */ argc -= optind; /* get ready for non-option args */ argv += optind; } /* End of options */ /*****************************************************************************/ arguments() { char *name; /* name of the input file */ /* * * postreverse only handles one input file at a time, so if there's more than one * argument left when we get here we'll quit. If none remain we copy stdin to a * temporary file and process that file. * */ if ( argc > 1 ) /* can't handle more than one file */ error(FATAL, "too many arguments"); if ( argc == 0 ) /* copy stdin to a temporary file */ name = copystdin(); else name = *argv; if ( (fp_in = fopen(name, "r")) == NULL ) error(FATAL, "can't open %s", name); reverse(); } /* End of arguments */ /*****************************************************************************/ done() { /* * * Cleans things up after we've finished reversing the pages in the input file. * All that's really left to do is remove the temp file, provided we used one. * */ if ( temp_file != NULL ) unlink(temp_file); } /* End of done */ /*****************************************************************************/ char *copystdin() { int fd_out; /* for the temporary file */ int fd_in; /* for stdin */ int count; /* number of bytes put in buf[] */ /* * * Copies stdin to a temporary file and returns the pathname of that file to the * caller. It's an expensive way of doing things, because it means we end up * reading the input file three times - rather than just twice. Could probably be * fixed by creating the temporary file on the fly as we read the file the first * time. * */ if ( (temp_file = tempnam(temp_dir, "post")) == NULL ) error(FATAL, "can't generate temp file name"); if ( (fd_out = creat(temp_file, 0660)) == -1 ) error(FATAL, "can't open %s", temp_file); fd_in = fileno(stdin); while ( (count = read(fd_in, buf, sizeof(buf))) > 0 ) if ( write(fd_out, buf, count) != count ) error(FATAL, "error writing to %s", temp_file); close(fd_out); return(temp_file); } /* End of copystdin */ /*****************************************************************************/ reverse() { /* * * Begins by looking for the ENDPROLOG comment in the input file. Everything up to * that comment is copied to the output file. If the comment isn't found the entire * input file is copied and moreprolog() returns FALSE. Otherwise readpages() reads * the rest of the input file and remembers (in pages[]) where each page starts and * ends. In addition everything bracketed by %%BeginGlobal and %%EndGlobal comments * is immediately added to the new prologue (or setup section) and ends up being * removed from the individual pages. When readpages() finds the TRAILER comment * or gets to the end of the input file we go back to the pages[] array and use * the saved offsets to write the pages out in reverse order. Finally everything * from the TRAILER comment to the end of the input file is copied to the output * file. * */ if ( moreprolog(ENDPROLOG) == TRUE ) { readpages(); writepages(); trailer(); } /* End if */ } /* End of reverse */ /*****************************************************************************/ moreprolog(str) char *str; /* copy everything up to this string */ { int len; /* length of FORMSPERPAGE string */ int vlen; /* length of VERSION string */ /* * * Looks for string *str at the start of a line and copies everything up to that * string to the output file. If *str isn't found the entire input file will end * up being copied to the output file and FALSE will be returned to the caller. * The first call (made from reverse()) looks for ENDPROLOG. Any other call comes * from readpages() and will be looking for the ENDSETUP comment. * */ len = strlen(FORMSPERPAGE); vlen = strlen(VERSION); while ( fgets(buf, sizeof(buf), fp_in) != NULL ) { if ( strcmp(buf, str) == 0 ) return(TRUE); else if ( strncmp(buf, FORMSPERPAGE, len) == 0 ) forms = atoi(&buf[len+1]); else if ( strncmp(buf, VERSION, vlen) == 0 ) version = atof(&buf[vlen+1]); fprintf(fp_out, "%s", buf); } /* End while */ return(FALSE); } /* End of moreprolog */ /*****************************************************************************/ readpages() { int endpagelen; /* length of ENDPAGE */ int pagelen; /* and PAGE strings */ int sawendpage = TRUE; /* ENDPAGE equivalent marked last page */ int gotpage = FALSE; /* TRUE disables BEGINSETUP stuff */ /* * * Records starting and ending positions of the requested pages (usually all of * them), puts global definitions in the prologue, and remembers where the TRAILER * was found. * * Page boundaries are marked by the strings PAGE, ENDPAGE, or perhaps both. * Application programs will normally find one or the other more convenient, so * in most cases only one kind of page delimiter will be found in a particular * document. * */ pages[0].start = ftell(fp_in); /* first page starts after ENDPROLOG */ endprolog = ENDPROLOG; endpagelen = strlen(ENDPAGE); pagelen = strlen(PAGE); while ( fgets(buf, sizeof(buf), fp_in) != NULL ) if ( buf[0] != '%' ) continue; else if ( strncmp(buf, ENDPAGE, endpagelen) == 0 ) { if ( in_olist(page++) == ON ) { pages[next_page].empty = FALSE; pages[next_page++].stop = ftell(fp_in); } /* End if */ pages[next_page].start = ftell(fp_in); sawendpage = TRUE; gotpage = TRUE; } else if ( strncmp(buf, PAGE, pagelen) == 0 ) { if ( sawendpage == FALSE && in_olist(page++) == ON ) { pages[next_page].empty = FALSE; pages[next_page++].stop = ftell(fp_in) - strlen(buf); } /* End if */ pages[next_page].start = ftell(fp_in) - strlen(buf); sawendpage = FALSE; gotpage = TRUE; } else if ( gotpage == FALSE && strcmp(buf, BEGINSETUP) == 0 ) { fprintf(fp_out, "%s", endprolog); fprintf(fp_out, "%s", BEGINSETUP); moreprolog(ENDSETUP); endprolog = ENDSETUP; } else if ( strcmp(buf, BEGINGLOBAL) == 0 ) { moreprolog(ENDGLOBAL); } else if ( strcmp(buf, TRAILER) == 0 ) { if ( sawendpage == FALSE ) pages[next_page++].stop = ftell(fp_in) - strlen(buf); endoff = ftell(fp_in); break; } /* End if */ } /* End of readpages */ /*****************************************************************************/ writepages() { int i, j, k; /* loop indices */ /* * * Goes through the pages[] array, usually from the bottom up, and writes out all * the pages. Documents that print more than one form per page cause things to get * a little more complicated. Each physical page has to have its subpages printed * in the correct order, and we have to build a few dummy subpages for the last * (and now first) sheet of paper, otherwise things will only occasionally work. * */ fprintf(fp_out, "%s", endprolog); if ( noreverse == FALSE ) /* fill out the first page */ for ( i = (forms - next_page % forms) % forms; i > 0; i--, next_page++ ) pages[next_page].empty = TRUE; else forms = next_page; /* turns reversal off in next loop */ for ( i = next_page - forms; i >= 0; i -= forms ) for ( j = i, k = 0; k < forms; j++, k++ ) if ( pages[j].empty == TRUE ) { if ( ignoreversion == TRUE || version > 3.1 ) { fprintf(fp_out, "%s 0 0\n", PAGE); fprintf(fp_out, "/saveobj save def\n"); fprintf(fp_out, "showpage\n"); fprintf(fp_out, "saveobj restore\n"); fprintf(fp_out, "%s 0 0\n", ENDPAGE); } else { fprintf(fp_out, "%s 0 0\n", PAGE); fprintf(fp_out, "save showpage restore\n"); fprintf(fp_out, "%s 0 0\n", ENDPAGE); } /* End else */ } else copypage(pages[j].start, pages[j].stop); } /* End of writepages */ /*****************************************************************************/ copypage(start, stop) long start; /* starting from this offset */ long stop; /* and ending here */ { /* * * Copies the page beginning at offset start and ending at stop to the output * file. Global definitions are skipped since they've already been added to the * prologue. * */ fseek(fp_in, start, 0); while ( ftell(fp_in) < stop && fgets(buf, sizeof(buf), fp_in) != NULL ) if ( buf[0] == '%' && strcmp(buf, BEGINGLOBAL) == 0 ) while ( fgets(buf, sizeof(buf), fp_in) != NULL && strcmp(buf, ENDGLOBAL) != 0 ) ; else fprintf(fp_out, "%s", buf); } /* End of copypage */ /*****************************************************************************/ trailer() { /* * * Makes sure everything from the TRAILER string to EOF is copied to the output * file. * */ if ( endoff > 0 ) { fprintf(fp_out, "%s", TRAILER); fseek(fp_in, endoff, 0); while ( fgets(buf, sizeof(buf), fp_in) != NULL ) fprintf(fp_out, "%s", buf); } /* End if */ } /* End of trailer */ /*****************************************************************************/