/*
*
* picpack - picture packing pre-processor
*
* A trivial troff pre-processor that copies files to stdout, expanding picture
* requests into an in-line format that's passed transparently through troff and
* handled by dpost. The program is an attempt to address requirements, expressed
* by several organizations, of being able to store a document as a single file
* (usually troff input) that can then be sent through dpost and ultimately to
* a PostScript printer.
*
* The program looks for strings listed in the keys[] array at the start of each
* line. When a picture request (as listed in keys[]) is found the second string
* on the line is taken to be a picture file pathname that's added (in transparent
* mode) to the output file. In addition each in-line picture file is preceeded by
* device control command (again passed through in transparent mode) that looks
* like,
*
*      x X InlinePicture filename bytes
*
* where bytes is the size of the picture file (which begins on the next line)
* and filename is the pathname of the picture file. dpost uses both arguments to
* manage in-line pictures (in a big temp file). To handle pictures in diversions
* picpack reads each input file twice. The first pass looks for picture inclusion
* requests and copies each picture file transparently to the output file, while
* second pass just copies the input file to the output file. Things could still
* break, but the two pass method should handle most jobs.
*
* The recognized in-line picture requests are saved in keys[] and by default only
* expand .BP and .PI macro calls. The -k option changes the recognized strings,
* and may be needed if you've built your own picture inclusion macros on top of
* .BP or .PI or decided to list each picture file at the start of your input file
* using a dummy macro. For example you could require every in-line picture be
* named by a dummy macro (say .iP), then the command line,
*
*      picpack -k.iP file > file.pack
*
* hits on lines that begin with .iP (rather than .BP or .PI), and the only files
* pulled in would be ones named as the second argument to the new .iP macro. The
* -k option accepts a space or comma separated list of up to 10 different key
* strings. picpack imposes no contraints on key strings, other than not allowing
* spaces or commas. A key string can begin with \" and in that case it would be
* troff comment.
*
* Although the program will help some users, there are obvious disadvantages.
* Perhaps the most important is that troff output files (with in-line pictures
* included) don't fit the device independent language accepted by important post
* processors like proof, and that means you won't be able to reliably preview a
* packed file on your 5620 or whatever. Another potential problem is that picture
* files can be large. Packing everything together in a single file at an early
* stage has a better chance of exceeding your system's ulimit.
*
*/

#include        <stdio.h>
#include        <sys/types.h>
#include        <sys/stat.h>
#include        <string.h>

#include        "gen.h"                 /* general purpose definitions */
#include        "ext.h"                 /* external variable definitions */
#include        "path.h"                /* just for TEMPDIR definition */

char            *keys[11] = {".BP", ".PI", NULL};
int             quiet = FALSE;

FILE            *fp_in = stdin;         /* input */
FILE            *fp_out = stdout;       /* and output files */

/*****************************************************************************/

main(agc, agv)

   int         agc;
   char        *agv[];

{

/*
*
* A picture packing pre-processor that copies input files to stdout, expanding
* picture requests (as listed in keys[]) to an in-line format that can be passed
* through troff (using transparent mode) and handled later by dpost.
*
*/

   argc = agc;                         /* global so everyone can use them */
   argv = agv;

   prog_name = argv[0];                /* just for error messages */

   options();                          /* command line options */
   arguments();                        /* translate all the input files */
   done();                             /* clean things up */

   exit(x_stat);                       /* everything probably went OK */

}   /* End of main */

/*****************************************************************************/

options()

{

   int         ch;                     /* name returned by getopt() */

   extern char *optarg;                /* option argument set by getopt() */
   extern int  optind;

/*
*
* Handles the command line options.
*
*/

   while ( (ch = getopt(argc, argv, "k:qDI")) != EOF )  {
       switch ( ch )  {
           case 'k':                   /* new expansion key strings */
                   newkeys(optarg);
                   break;

           case 'q':                   /* disables "missing picture" messages */
                   quiet = TRUE;
                   break;

           case 'D':                   /* debug flag */
                   debug = ON;
                   break;

           case 'I':                   /* ignore FATAL errors */
                   ignore = ON;
                   break;

           case '?':                   /* don't know the option */
                   error(FATAL, "");
                   break;

           default:
                   error(FATAL, "missing case for option %c", ch);
                   break;
       }   /* End switch */
   }   /* End while */

   argc -= optind;                     /* get ready for non-options args */
   argv += optind;

}   /* End of options */

/*****************************************************************************/

newkeys(list)

   char        *list;                  /* comma or space separated key strings */

{

   char        *p;                     /* next key string from *list */
   int         i;                      /* goes in keys[i] */
   int         n;                      /* last key string slot in keys[] */

/*
*
* Separates *list into space or comma separated strings and adds each to the
* keys[] array. The strings in keys[] are used to locate the picture inclusion
* requests that are translated to the in-line format. The keys array must end
* with a NULL pointer and by default only expands .BP and .PI macro calls.
*
*/

   n = (sizeof(keys) / sizeof(char *)) - 1;

   for ( i = 0, p = strtok(list, " ,"); p != NULL; i++, p = strtok(NULL, " ,") )
       if ( i >= n )
           error(FATAL, "too many key strings");
       else keys[i] = p;

   keys[i] = NULL;

}   /* End of newkeys */

/*****************************************************************************/

arguments()

{

   FILE        *copystdin();

/*
*
* Makes sure all the non-option command line arguments are processed. If we get
* here and there aren't any arguments left, or if '-' is one of the input files
* we process stdin, after copying it to a temporary file.
*
*/

   if ( argc < 1 )  {
       fp_in = copystdin();
       picpack();
   } else
       while ( argc > 0 ) {
           if ( strcmp(*argv, "-") == 0 )
               fp_in = copystdin();
           else if ( (fp_in = fopen(*argv, "r")) == NULL )
               error(FATAL, "can't open %s", *argv);
           picpack();
           fclose(fp_in);
           argc--;
           argv++;
       }   /* End while */

}   /* End of arguments */

/*****************************************************************************/

FILE *copystdin()

{

   char        *tfile;                 /* temporary file name */
   int         fd_out;                 /* and its file descriptor */
   FILE        *fp;                    /* return value - the new input file */

/*
*
* Copies stdin to a temp file, unlinks the file, and returns the file pointer
* for the new temporary file to the caller. Needed because we read each input
* file twice in an attempt to handle pictures in diversions.
*
*/

   if ( (tfile = tempnam(TEMPDIR, "post")) == NULL )
       error(FATAL, "can't generate temp file name");

   if ( (fd_out = creat(tfile, 0660)) == -1 )
       error(FATAL, "can't create %s", tfile);

   copyfile(fileno(stdin), fd_out);
   close(fd_out);

   if ( (fp = fopen(tfile, "r")) == NULL )
       error(FATAL, "can't open %s", tfile);

   unlink(tfile);
   return(fp);

}   /* End of copystdin */

/*****************************************************************************/

copyfile(fd_in, fd_out)

   int         fd_in;                  /* input */
   int         fd_out;                 /* and output files */

{

   char        buf[512];               /* internal buffer for reads and writes */
   int         count;                  /* number of bytes put in buf[] */

/*
*
* Copies file fd_in to fd_out. Handles the second pass for each input file and
* also used to copy stdin to a temporary file.
*
*/

   while ( (count = read(fd_in, buf, sizeof(buf))) > 0 )
       if ( write(fd_out, buf, count) != count )
           error(FATAL, "write error");

}   /* End of copyfile */

/*****************************************************************************/

done()

{

/*
*
* Finished with all the input files - unlink the temporary file that was used
* to record the in-line picture file pathnames.
*
*/

   if ( temp_file != NULL )
       unlink(temp_file);

}   /* End of done */

/*****************************************************************************/

picpack()

{

   char        line[512];              /* next input line */
   char        name[100];              /* picture file names - from BP or PI */
   int         i;                      /* for looking through keys[] */

/*
*
* Handles the two passes over the next input file. First pass compares the start
* of each line in *fp_in with the key strings saved in the keys[] array. If a
* match is found inline() is called to copy the picture file (ie. the file named
* as the second string in line[]) to stdout, provided the file hasn't previously
* been copied. The second pass goes back to the start of fp_in and copies it all
* to the output file.
*
*/

   while ( fgets(line, sizeof(line), fp_in) != NULL )  {
       for ( i = 0; keys[i] != NULL; i++ )
           if ( strncmp(line, keys[i], strlen(keys[i])) == 0 )  {
               if ( sscanf(line, "%*s %s", name) == 1 )  {
                   strtok(name, "(");
                   if ( gotpicfile(name) == FALSE )
                       inline(name);
               }   /* End if */
           }   /* End if */
   }   /* End while */

   fflush(fp_out);                     /* second pass - copy fp_in to fp_out */
   fseek(fp_in, 0L, 0);
   copyfile(fileno(fp_in), fileno(fp_out));

}   /* End of picpack */

/*****************************************************************************/

inline(name)

   char        *name;                  /* name of the in-line picture file */

{

   long        size;                   /* size in bytes - from fstat */
   FILE        *fp;                    /* for reading *name */
   int         ch;                     /* next character from picture file */
   int         lastch = '\n';          /* so we know when to put out \! */

   struct stat sbuf;                   /* for the picture file size */

/*
*
* Copies the picture file *name to the output file in an in-line format that can
* be passed through troff and recovered later by dpost. Transparent mode is used
* so each line starts with \! and all \ characters must be escaped. The in-line
* picture sequence begins with an "x X InlinePicture" device control command that
* names the picture file and gives its size (in bytes).
*
*/

   if ( (fp = fopen(name, "r")) != NULL )  {
       fstat(fileno(fp), &sbuf);
       if ( (size = sbuf.st_size) > 0 )  {
           fprintf(fp_out, "\\!x X InlinePicture %s %ld\n", name, size);
           while ( (ch = getc(fp)) != EOF )  {
               if ( lastch == '\n' )
                   fprintf(fp_out, "\\!");
               if ( ch == '\\' )
                   putc('\\', fp_out);
               putc(lastch = ch, fp_out);
           }   /* End while */
           if ( lastch != '\n' )
               putc('\n', fp_out);
       }    /* End if */
       fclose(fp);
       addpicfile(name);
   } else if ( quiet == FALSE )
       error(NON_FATAL, "can't read picture file %s", name);

}   /* End of inline */

/*****************************************************************************/

gotpicfile(name)

   char        *name;

{

   char        buf[100];
   FILE        *fp_pic;

/*
*
* Checks the list of previously added picture files in *temp_file and returns
* FALSE if it's a new file and TRUE otherwise. Probably should open the temp
* file once for update and leave it open, rather than opening and closing it
* every time.
*
*/

   if ( temp_file != NULL )
       if ( (fp_pic = fopen(temp_file, "r")) != NULL )  {
           while ( fscanf(fp_pic, "%s", buf) != EOF )
               if ( strcmp(buf, name) == 0 )  {
                   fclose(fp_pic);
                   return(TRUE);
               }   /* End if */
           fclose(fp_pic);
       }   /* End if */

   return(FALSE);

}   /* End of gotpicfile */

/*****************************************************************************/

addpicfile(name)

   char        *name;

{

   FILE        *fp_pic;

/*
*
* Adds string *name to the list of in-line picture files that's maintained in
* *temp_file. Should undoubtedly open the file once for update and use fseek()
* to move around in the file!
*
*/

   if ( temp_file == NULL )
       if ( (temp_file = tempnam(TEMPDIR, "picpac")) == NULL )
           return;

   if ( (fp_pic = fopen(temp_file, "a")) != NULL )  {
       fprintf(fp_pic, "%s\n", name);
       fclose(fp_pic);
   }   /* End if */

}   /* End of addpicfile */

/*****************************************************************************/