A postcript viewer. It decodes a .ps - Postscript

/*********************************************************************/
/*                                  */
/* Title:    dpview.c                      */
/*                                  */
/* Comments:  This program takes the input of a Postcript file,  */ 
/*        converts the codes in it to plain text which is   */
/*        displayed and re-directable.            */
/*                                  */
/* Author:   David Yuan                     */
/*                                  */
/* Date Created:  19/04/1996                    */
/*                                  */
/* Date Last Modified:  16/06/1996                */
/*                                  */
/* Permission of distribution is granted, provided no alternation, */
/*    commenting or modification is made towards any parts of   */
/*    the source code and the binary code.            */
/*                                  */
/*********************************************************************/
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include "file_handle.c"
#include "fggets.c"
#define INDICATOR_STR1     "%%EndSetup"       /* First string to be searched */
#define INDICATOR_STR2     "%%Page"         /* Second string to be searched */
#define SPACE_CHAR       0x20           /* space character */
#define NULL_CHAR       0x0           /* null character */
#define BACK_SLASH       '\\'           /* back slash character */
#define L_BRACKET       '('           /* left bracket character */
#define R_BRACKET       ')'           /* right bracket character */
#define S_QUOTE        '\''           /* single quotation mark */
#define D_QUOTE        '"'           /* double quotation mark */
#define TRUE          1            /* Logical constant */
#define FALSE         0            /* Logical constant */
#define KILO_BYTE       1024           /* machine related constant */
#define MAX_STR_LEN      512           /* Longest length of string allowed */
#define MAX_BUFR_SIZE     (KILO_BYTE * 16)     /* Define 16KB buffer size for */
							/* both input and output file */
#define output_line(x)                 fprintf(outf, "%s\n", (x))
#define output_line_break                fprintf(outf, "\n")
#define output_line_without_line_break(x)        fprintf(outf, "%s", (x))
#ifndef __BORLANDC__
 char inbufr[MAX_BUFR_SIZE];              /* reserve space for input file buffers */
 char outbufr[MAX_BUFR_SIZE];             /* reserve space for output file buffers */
#endif
typedef int BOOL;                    /* Define boolean type */
FILE *inf;                       /* handle of input file */
FILE *outf;                       /* handle of output file */
FILE *errf;                       /* handle of error log file */
char Linebuff[MAX_STR_LEN];               /* pre-allocated input line buffer */
char Outbuff[MAX_STR_LEN];               /* pre-allocated output line buffer */
char Indcbuff[MAX_STR_LEN];               /* pre-allocated string buffer */
char Sub_string[MAX_STR_LEN];              /* pre-allocated string buffer */
char * pLinebuff;                    /* pointer to input line buffer */
char * pOutbuff;                    /* pointer to output line buffer */
char * pIndcbuff;                    /* pointer to string buffer */
char * pSubstr;                     /* pointer to another string buffer */
int pageno = 0;                    /* page number to be inserted into the page break */
int done = 0;                     /* indicator for end of line */
 
BOOL dp_error = FALSE;                 /* boolean variable */
							/* when error happens it is set to be TRUE */
BOOL supress_page_break = FALSE;            /* variable to decide whether */
							/* output page break or not */
/* close all opened files */
/* write message to error log if necessary */
void closefiles(void)
{
 fclose(inf);
 fclose(outf);
 if (!dp_error) fprintf(errf, "\nNo error.\n");
 fclose(errf);
}
/* display and write to error log file a message about non-Postscript format */
void msgNonPS(void)
{
 printf("\nError-->Non-Postcript input file.\n\n");
 fprintf(errf, "\nError-->Non-Postcript input file.\n\n");
 closefiles();
 exit(-9);
}
/* writes a page break into output file */
void output_page_break()
{
 pageno++;
 if (!supress_page_break)
  fprintf(outf, "\n\n============================ Page %i ===========================\n\n\n", pageno);
 return;
}
/* copy characters between two pointers: p1 and p2 */
/* to the location starting: p0 */
/* if p2 is pointed to an address smaller than p1 */
/* this loop will terminate and NULL string returned */
char * getSubstring(char * p0, char * p1, char * p2)
{
 char * temp1;
 char * temp2;
 /* copy characters */
 temp1 = p0;
 temp2 = p1;
 /* terminate if p1 is pointed address after p2 */
 if (p1 <= p2)
 {
   if (p1[0] == L_BRACKET)
   {
    /* search until right bracket is found */
    while ((temp2[0] != R_BRACKET) && (temp2[0] != NULL_CHAR)) {
	 temp1[0] = temp2[0];
	 temp1++;
	 temp2++;
    }
    /* do not forget to copy the character pointed by: p2 */
    temp1[0] = temp2[0];
   }
   else
   {
    /* just find the next space or EOL character */
    while (temp2 != p2) {
	 temp1[0] = temp2[0];
	 temp1++;
	 temp2++;
    }
    /* do not forget to copy the character pointed by: p2 */
    temp1[0] = temp2[0];
   }
 }
 (++temp1)[0] = NULL_CHAR;
 (++temp1)[0] = NULL_CHAR;
 return temp2;
}
/* analyze the line read-in from input file */
/* source line pointer passed in by char * s1 */
/* pointer analyzed line stored and passed out by char * s2 */
int analyze_line(char * s1, char * s2)
{
 int RC = 0;
 char * c1;
 char * c2;
 char * c3;
 char * c4;
 char * c5;
 int n_ptr;
 char numero[MAX_STR_LEN];
 c1 = s1;
 c2 = s2;
 /* set the analyze result string to be blank */
 c2[0] = NULL_CHAR;
 c2[1] = NULL_CHAR;
 /* handle comment lines */
 /* in Postscript, comment lines start with two percentage signs: "%%" */
 if (strstr(c1, "%%") == c1) return RC;
 while (c1[0])
 {
  /* skip spaces and TAB keys */
  c3 = c1;
  while ((c3[0] <= SPACE_CHAR) && (c3[0])) c3++;
  /* at the end of input string */
  if (!c3[0])
  {
   if (strlen(s2) > 0)
   {
	output_line_without_line_break(s2);
	c2 = s2;
	s2 = NULL_CHAR;
   }
   break;
  }
  /* starting of a word */
  c1 = c3;
  if (c1[0] != L_BRACKET)
  {
   if (c1[0] == R_BRACKET)
   {
	while ((c1[0] == SPACE_CHAR) || (c1[0] == R_BRACKET)) c1++;
	c3 = c1;
   }
   while ((c3[0] > SPACE_CHAR) && (!c3[0])
	 && (c3[0] != L_BRACKET) && (c3[0] != R_BRACKET)) c3++;
   c3--;
   /* getting of a sub-string */
   c3 = getSubstring(pSubstr, c1, c3);
  }
  else
  {
   while ((c3[0] > SPACE_CHAR) && (!c3[0]) && (c3[0] != R_BRACKET))
   {
	if (c3[0] != BACK_SLASH)
	 c3++;
	else
	{
	 c3++;
	 c3++;
	}
   }
   /* getting of a sub-string */
   c3 = getSubstring(pSubstr, c1, c3);
  }
  /* update current char pointer */
  c1 = c3;
  c1++;
  /* discriminate the token read-in */
  switch (strlen(pSubstr))
  {
   case 0: break;
   case 1: {
		switch (pSubstr[0])
		{
		 case 'y':
		 case 'T':
		 case 'P':
		 case 'Q':
		 {
		  c2[0] = NULL_CHAR;
		  if (strlen(s2) > 0)
		   output_line(s2);
		  else
		   output_line_break;
		  if (pSubstr[0] == 'Q')
		   output_line_break;
		  c2 = s2;
		  s2[0] = NULL_CHAR;
		  s2[1] = 0;
		  break;
		 }
		 case 'b':
		 case 'c':
		 case 'd':
		 case 'e':
		 case 'f':
		 case 'g':
		 case 'h':
		 case 'i':
		 case 'j':
		 case 'k':
		 {
		  /* between 'b' and 'k' */
		  c2[0] = SPACE_CHAR;
		  c2++;
		  c2[0] = NULL_CHAR;
		  break;
		 }
		}
	   }
   default: {
		if (strcmp(pSubstr, "eop") == 0)
		{
		 if (strlen(s2) > 0)
		  output_line(s2);
		 c2 = s2;
		 s2[0] = NULL_CHAR;
		 s2[1] = NULL_CHAR;
		 output_page_break();
		 break;
		}
		/* a displayable word entered */
		if ((pSubstr[0] == L_BRACKET) && (pSubstr[strlen(pSubstr)-1] == R_BRACKET))
		{
		 if (strchr(pSubstr, SPACE_CHAR) != NULL)
		 {
		  if (strstr(pSubstr, "(Error: )") != NULL) break;
		  if (strstr(pSubstr, "(converted error name will end") != NULL) break;
		  if (strstr(pSubstr, "(converted stack will end") != NULL) break;
		  if (strstr(pSubstr, "(Stack: )") != NULL) break;
		  if (strstr(pSubstr, "(Incompatable color bitimage") != NULL) break;
		  if (strstr(pSubstr, "(Offending Command:") != NULL) break;
		 }
		 c4 = pSubstr + 1;
		 while (!c4[0])
		 {
		  switch (c4[0])
		  {
		   case R_BRACKET:
			   c2[0] = 0;
			   c2--;
			   break;
		   case BACK_SLASH:
			   c4++;
			   if (!isdigit(c4[0]))
			    c2[0] = c4[0];
			   else
			   /* handle number */
			   {
			    c5 = c4;
			    n_ptr = 0;
			    while ((isdigit(c5[0])) && (n_ptr < 3)) {
				 numero[n_ptr++] = c5[0];
				 c5++;
			    }
			    numero[n_ptr] = 0;
			    switch (atoi(numero))
			    {
				 case 13:
				  (c2++)[0] = 'f';
				  c2[0] = 'f';
				  break;
				 case 14:
				 case 336:
				  (c2++)[0] = 'f';
				  c2[0] = 'i';
				  break;
				 case 322:
				 case 323:
				  c2[0] = D_QUOTE;
				  break;
				 case 324:
				 case 325:
				  c2[0] = S_QUOTE;
				  break;
				 case 134:
				  c2[0] = BACK_SLASH;
				  break;
				 case 50:
				  c2[0] = L_BRACKET;
				  break;
				 case 51:
				  c2[0] = R_BRACKET;
				  break;
				 case 245:
				  (c2++)[0] = '+';
				  c2[0] = SPACE_CHAR;
				  break;
				 default:c2[0] = (char) atoi(numero);
			    }
			    c4 = c5 - 1;
			   }
			   break;
		   default:
			   c2[0] = c4[0];
			   break;
		   }
		  }
		  c2++;
		  c4++;
		  c2[0] = NULL_CHAR;
		 break;
		}
		break;
	   }
  }   /* the biggest switch statement in this program */
 }
 /* flush line buffer if it is not empty */
 if (strlen(s2) > 0)
  output_line_without_line_break(s2);
 s2[0] = NULL_CHAR;
 s2[1] = NULL_CHAR;
 return RC;
}
/* to check the first line of the file to tell */
/* if it is a Postscript formatted file */
void verifyPostscript(void)
{
 /* read one non-blank line */
 do {
  fggets(pLinebuff, 1024, &done, inf);
 } while (!strlen(pLinebuff));
 /* check the Postscript indicator */
 if (strstr(pLinebuff, "%!PS") != pLinebuff)
  msgNonPS();
 else
  return;
}
/* to display usage on the stdio */
/* argument name is the program name */
void displayUsage(char * name)
{
 char * ptr;
 char * nameptr;
 char nname[100];
 strcpy(nname, name);
 /* find the last back slash character */
 ptr = strrchr(nname, BACK_SLASH);
 if (ptr)
  nameptr = ++ptr;
 else
  nameptr = name;
#ifdef __BORLANDC__
 /* find the dot, then put a NULL-CHARACTER at that place */
 ptr = strrchr(nname, '.');
 if (ptr) ptr[0] = NULL;
#endif
#ifdef MSDOS
 /* find the dot, then put a NULL-CHARACTER at that place */
 if (ptr = strrchr(nname, '.')) ptr[0] = NULL_CHAR;
#endif
 printf("\nUsage: %s PS-file-name [ -b ]", nameptr);
 printf("\n    (dump content of PS file onto the screen.)");
 printf("\n\noptional -b: suppress page-break within output");
 printf("\n\nother usage: %s PS-file-name [ -b ] > Text-file-name", nameptr);
 printf("\n\n       %s PS-file-name [ -b ] | more", nameptr);
 printf("\n\nCopyright: David Yuan (C), Deakin University, May, 1996.\n\n");
 fprintf(errf, "\nError-->No argument is supplied.\n\n");
 fclose(errf);
}
/* Main body of the program */
void main(int argCount, char **argument)
{
 /* to reserve space for both input and output file buffers */
#ifdef __BORLANDC__
 char inbufr[MAX_BUFR_SIZE];
 char outbufr[MAX_BUFR_SIZE];
#endif
 /* To set up pointers to the text buffers, */
 /* such arrangement make sure the program to be simple and fast */
 /* no malloc() or free() function call is necessary */
 /* set every bytes in these strings to be NULL char as precaution */
 pLinebuff = (char *) (&Linebuff);
 memset(pLinebuff, NULL_CHAR, MAX_STR_LEN - 1);
 pOutbuff = (char *) (&Outbuff);
 memset(pOutbuff, NULL_CHAR, MAX_STR_LEN - 1);
 pIndcbuff = (char *) (&Indcbuff);
 memset(pIndcbuff, NULL_CHAR, MAX_STR_LEN - 1);
 pSubstr = (char *) (&Sub_string);
 memset(pSubstr, NULL_CHAR, MAX_STR_LEN - 1);
 /* pre-open the error log file */
 errf = fopen("DPVIEW.ERROR", TEXT_WRITE);
 /* handles arguments of the program */
 /* display usage information if wrong number of arguments given */
 if ((argCount < 2) || (argCount > 4))
 {
  displayUsage(argument[0]);
  exit(0);
 }
 /* supress string */
 if ((strcmp(argument[2], "-b") == 0)) supress_page_break = TRUE;
 /* check the existance of the input file */
 if (argCount >= 2)
 {
  if ((inf = fopen(argument[1], TEXT_READ)) == NULL)
  {
   printf("\nError-->File: %s can not be opened.\n\n", argument[1]);
   fprintf(errf, "\nError-->File: %s can not be opened.\n\n", argument[1]);
   fclose(inf);
   fclose(errf);
   exit(-1);
  }
  else
  {
  /* attempt to set up input file buffer */
   if ((setvbuf(inf, (char *)(&inbufr), _IOLBF, MAX_BUFR_SIZE)) != 0)
   {
	printf("\nError-->System memory too low to execute program.\n\n");
	fprintf(errf, "\nError-->System memory too low to execute program.\n\n");
	fclose(inf);
	fclose(errf);
	exit(-5);
   }
   else
	verifyPostscript();
  }
 }
 /* dump output to screen */
 outf = (FILE *) (stdout);
 /* read in input file line by line */
 /* until the first indicator string is found */
 strcpy(pIndcbuff, INDICATOR_STR1);
 while (!done)
 {
  fggets(pLinebuff, 1024, &done, inf);
  if (strstr(pLinebuff, pIndcbuff) != NULL)
  {
   if ((feof(inf))) done = 1;
   break;
  }
 }
 /* read in input file line by line */
 /* until the second indicator string is found */
 /* The real PS text content begins from the next line */
 strcpy(pIndcbuff, INDICATOR_STR2);
 while (!done)
 {
  fggets(pLinebuff, 1024, &done, inf);
  if (strstr(pLinebuff, pIndcbuff) != NULL)
  {
   if ((feof(inf))) done = 1;
   break;
  }
 }
 /* read in input file line by line */
 /* analyze it and output plain text into output file */
 do {
  fggets(pLinebuff, 1024, &done, inf);
  analyze_line(pLinebuff, pOutbuff);
  if ((feof(inf))) done = 1;
 } while (!done);
 /* close input, output and error log files */
 closefiles();
 return;
}
/* End of main body of the program */