ref: 4d69aacea023546a7150d92e147e531c38de822f
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(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(void)
{
/*
*
* 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(void)
{
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(void)
{
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(void)
{
/*
*
* 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(void)
{
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(void)
{
/*
*
* 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(char *str)
{
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(void)
{
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(void)
{
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(long start, long stop)
{
/*
*
* 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(void)
{
/*
*
* 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 */
/*****************************************************************************/