usage.c

This is code tutorial for image processing include:histogram,sketon....

   input_file = NULL;

/* A. */
   strcpy(input_file_name, input_name);
   if(has_dot_in_name(input_file_name)){
      printf("\nTry to open %s\n", input_file_name);
      if((input_file = 
             fopen(input_file_name, "rt")) == NULL){
         printf("\nusage: Cannot open input file %s\n",
                input_file_name);
      }  /* ends if input_file */
   }  /* ends if has_dot_in_name */

/* B. */
   else{

/* C. */
         /* Try .c */
      strcpy(temp_string, input_file_name);
      strcat(temp_string, ".c");
      printf("\nTry to open %s\n", temp_string);
      if((input_file = 
         fopen(temp_string, "rt")) == NULL){
         printf("\nusage: Could not open file %s",
            temp_string);
      }  /* ends if input_file .c */
      else
         havent_found_file = 0;

/* D. */
            /* Try .cpp */
      if(havent_found_file){
         strcpy(temp_string, input_file_name);
         strcat(temp_string, ".cpp");
         printf("\nTry to open %s\n", temp_string);
         if((input_file = 
            fopen(temp_string, "rt")) == NULL){
            printf("\nusage: Could not open file %s",
               temp_string);
         }  /* ends if input_file .cpp */
         else
            havent_found_file = 0;
      }  /* ends if havent_found_file */

/* E. */
            /* Try .f or anything other extension */
      if(havent_found_file){
         strcpy(temp_string, input_file_name);
         strcat(temp_string, ".f");
         printf("\nTry to open %s\n", temp_string);
         if((input_file = 
             fopen(temp_string, "rt")) == NULL){
             printf("\nusage: Could not open file %s",
                    temp_string);
         }  /* ends if input_file .f */
         else
            havent_found_file = 0;
      }  /* ends if havent_found_file */

   }  /* ends else does not have dot in name */

   return(input_file);

}  /* ends find_and_open_input_file */
/**************************************************/
/*PAGE paginate_file function

  paginate_file(...

  This function breaks the input file into pages 
  and inserts spaces at the left edge of the page.
  The output is sent to an output text file.

   A. Read the date and time and put them into 
      the time string.
   B. Print the header for the first page.
   C. Read all the lines in the input file.
   D. Look for the start marker.
      E. Once you find the start marker, read the
         information.
      F. Send the line to the output file as long 
         as it is not the end marker.
      G. If you send a full screen of text to the
         output file, make a new page in the output
         file.
      H. When you hit the end marker, quit 
         sending the text to the output file.
      I. At the end of the input file, fill the last
         page of the output file with blank lines.

*/
void paginate_file(FILE *input_file, 
                   FILE *output_file,
                   char *name_of_input_file,
                   char start[],
                   char end[])
{
   char   *f_result, 
          string[LENGTH], 
          time_string[LENGTH];
   int    i,
          first_page       = 1,
          line_counter     = 0,
          page_counter     = 1,
          reading_usage,
          toc_line_counter = 0;
   struct tm *time_of_day;
   time_t seconds;

/* A. */
   time(&seconds);
   time_of_day = localtime(&seconds);
   sprintf(time_string, "%d-%d-%d\0",
           time_of_day->tm_mon+1,
           time_of_day->tm_mday,
           time_of_day->tm_year);

/* B. */
   write_3_line_header(output_file, name_of_input_file,
                       time_string, &page_counter);
   line_counter = line_counter + 3;
   blank_line(output_file);
   ++line_counter;

/* C. */
   while(fgets(string, LENGTH+1, input_file)){
/* D. */
      if(strncmp(string, start, 3) == 0){
         reading_usage = 1;
/* E. */
         while(reading_usage){
            f_result = fgets(string, 
                             LENGTH+1, 
                             input_file);
            if(f_result == NULL) 
               reading_usage = 0;
/* F. */
            if((reading_usage == 1)   &&
               (strncmp(string, end, 6) != 0)){
               pad_string(string, TAB_SPACE);
               fputs(string, output_file);
               ++line_counter;
/* G. */
               if(line_counter >= LPP-FOOT_SPACE)
                  make_new_page(input_file, 
                                output_file,
                                name_of_input_file, 
                                time_string,
                                &page_counter, 
                                &line_counter);
                     }  /* ends if */
/* H. */             
            if(strncmp(string, end, 6) == 0)
               reading_usage = 0;
         }  /* ends while reading_usage */
         
      }  /* ends if found USAGE */

   }  /* end of while fgets */

/* I. */
   for(i=line_counter; i<=LPP; i++)
      blank_line(output_file);

} /* end of paginate_file function */
/**************************************************/
/*PAGE pad_string function

  pad_string(...

  This function inserts spaces into the beginning 
  (left side) of a string.

  A. Declare variables.
  B. Fill a temporary string with num_blanks spaces.
  C. Concatenate input string onto temporary string.
  D. Copy temporary string back to input string.

*/

void pad_string(char string[], 
               int   num_blanks)
{
/* A. */
   int   count;
   char  temp[LENGTH];

/* B. */
   for(count = 0; count < num_blanks; count++)
      temp[count] = ' ';
   temp[count] = '\0';
/* C. */
   strcat(temp, string);
/* D. */
   strcpy(string, temp);

}  /* end of pad_string function */
/**************************************************/
/*PAGE write_3_line_header function

  write_3_line_header(...

  This function writes a three line header to the 
  top of a new page.  The header contains the file 
  name, date, and page number.

  A. Declare variables.
  B. Fill strings with blanks.
  C. Fill strings with information and send to
        the output file.

*/
void write_3_line_header(FILE *file, 
                         char *file_name,
                         char *time_string, 
                         int  *page_number)
{
/* A. */
   char b1[LENGTH], 
        b2[LENGTH], 
        b3[LENGTH], 
        string[LENGTH];
   int  i;

/* B. */
   for(i=0; i<LENGTH; i++){
      b1[i]     = ' ';
      b2[i]     = ' ';
      b3[i]     = ' ';
      string[i] = ' ';
   } /* end of loop over i */

   b1[LENGTH-15] = '\0';
   b2[LENGTH-15] = '\0';
   b3[LENGTH-15] = '\0';

/* C. */
   sprintf(string, "%s\n", file_name);
   strcat(b1, string);
   fputs(b1, file);

   sprintf(string, "%s\n", time_string);
   strcat(b2, string);
   fputs(b2, file);

   sprintf(string, "Page %d\n", *page_number);
   strcat(b3, string);
   fputs(b3, file);

}  /* end of write_3_line_header function */
/**************************************************/
/*PAGE blank_line function
 
  blank_line(...
  
  This function sends a blank line to a file.
*/

void blank_line(FILE *file)
{
   fputs("          \n", file);
} /* end of blank_line function */
/**************************************************/
/*PAGE make_new_page function

  make_new_page(...

  This function fills the remainder of a page with 
  blank lines and prints a header at the top of the 
  next page.

  A. Declare variables.
  B. Loop until the page runs out of lines.
  C. If you reach the end of a page, then
        D. Print FOOTER blank lines, jump to the 
           next page, and print a page header.

*/
void make_new_page(FILE *input_file, 
                   FILE *output_file,
                   char *name_of_input_file, 
                   char *time_string,
                   int  *page_counter, 
                   int  *line_counter)
{
/* A. */
   int  i, not_finished = 1;

/* B. */
   while(not_finished){

/* C. */
      if(*line_counter >= LPP - FOOT_SPACE){

/* D. */
         not_finished = 0;
         for(i=0; i<FOOTER; i++) 
            blank_line(output_file);
         *line_counter = 0;
         *page_counter = *page_counter + 1;
         blank_line(output_file);
         *line_counter = *line_counter + 1;
         write_3_line_header(output_file, 
                             name_of_input_file,
                             time_string, 
                             page_counter);
         *line_counter = *line_counter + 3;
         blank_line(output_file);
         *line_counter = *line_counter + 1;
      }  /* end of if line counter >= LPP - 10 */
      fputs("     \n", output_file);
      *line_counter = *line_counter + 1;
   }  /* end of while not_finished */
}  /* end of make_new_page function */
/**************************************************/