usage.c

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/*PAGE The Beginning */
/*
   usage.c
   Dwayne Phillips
   1 October 1994


USAGE
      usage file.c -e -p out-file-name
      usage file.cpp -e -p out-file-name
      usage file -e -p out-file-name
         given no extension to file look for .c 
         .cpp and .f
      -p means print it to the out-file-name
      -e means explain it to the programmer

      "man" like controls
      Q or q quits (of course ctrl-c does too)
      space advances a full screen
      Enter advances one line

      You can have more than one USAGE and EXPLAIN
      blocks in the source code.
ENDUSAGE


EXPLAIN
      This program pulls lines of information out of
      the source code text of a text file.  This is
      all basic text I/O using fgets, fputs, and
      printf (more EXPLAIN text to follow).
ENDEXPLAIN
*/
/**************************************************/
/*PAGE Includes and Defines */
#include <time.h>
#include <io.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <malloc.h>

#define BLANK      ' '
#define LENGTH      80
#define LPP         66
#define LPS         15
#define MAX_STRING 255
#define PAGE_TYPE   10
#define TAB_SPACE    5
#define FOOT_SPACE  10
#define FOOTER       4
#define DEBUG

char s_use[LENGTH] = "USAGE";
char e_use[LENGTH] = "ENDUSAGE";
char s_exp[LENGTH] = "EXPLAIN";
char e_exp[LENGTH] = "ENDEXPLAIN";
/**************************************************/
/*PAGE Function Prototypes */
int  has_dot_in_name();
void display_usage();
FILE *find_and_open_input_file();
void pad_string();
void write_3_line_header();
void blank_line();
void paginate_file();
void make_new_page();
/**************************************************/
/*PAGE main */
/*
   A. Quit if the wrong number of parameters.
   B. Loop through the parameters
      C. If only two parameters, then the second
         one is the input file name.
      D. Otherwise, go through each one and look
         for the -e and -p options. 
   E. Open the input file if it exists.
   F. If the user chose to show the usage information
      G. Print it to a file, or
      H. Show it to the screen.
   I. If the user chose to show the explain information
      J. Print it to a file, or
      K. Show it to the screen.
   L. Close the files and end the program.

*/

main(int argc, char *argv[])
{
   char  out_file_name[LENGTH],
         temp_string[LENGTH];

   FILE  *input_file, *out_file;

   int   i,
         print_output      = 0,
         show_explain      = 0,
         show_usage        = 0;


/* A. */
   if(argc < 2  || argc > 5){
      printf("\nusage: usage input-file [-p -e]");
      exit(1);
   } 

/* B. */
/* C. */
   if(argc == 2){
      strcpy(temp_string, argv[1]);
   }

/* D. */
   else{
      i=1;

      while(i < argc){
         if(argv[i][0] == '-'){

            if(strcmp(argv[i], "-p") == 0){
               print_output = 1;
               i++;
               strcpy(out_file_name, argv[i]);
            }  /* ends if -p */
            if(strcmp(argv[i], "-e") == 0){
               show_explain = 1;
               show_usage   = 0;
            }  /* ends if -e */

         }  /* ends if argv[i][0] == '-' */

         else{  /* argv[i] is the input file name */
            strcpy(temp_string, argv[i]);
         }  /* ends else argv[i][0] != '-' */
         i++;
      }  /* ends while i < argc */

   }  /* ends else loop through the arguments */

   if(show_explain == 0) show_usage = 1;

/* E. */   
   input_file = find_and_open_input_file(temp_string);
   if(input_file == NULL){
      printf("\nusage: cannot open input file");
      exit(10);
   }


/* F. */
   if(show_usage){
/* G. */
      if(print_output){
         if((out_file = 
             fopen(out_file_name, "wt")) == NULL)
            printf("\nusage: Cannot open out file %s",
               out_file_name);
         paginate_file(input_file, out_file, 
                       temp_string, s_use, e_use);
      }  /* ends if print_output */
/* H. */
      else{  /* show usage to the screen */
         display_usage(input_file, s_use, e_use);
      }  /* ends show usage to the screen */
   }  /* ends if show usage */

/* I. */
   if(show_explain){
/* J. */
      if(print_output){
         if((out_file = 
             fopen(out_file_name, "wt")) == NULL)
            printf("\nusage: Cannot open out file %s",
               out_file_name);
         paginate_file(input_file, out_file, 
                       temp_string, s_exp, e_exp);
      }  /* ends if print_output */
/* K. */
      else{  /* show explain to the screen */
         display_usage(input_file, s_exp, e_exp);
      }  /* ends show explain to the screen */
   }  /* ends if show explain */

/* L. */
   fclose(input_file);
   fclose(out_file);
   return(1);
}  /* end of main */
/*************************************************/
/*PAGE has_dot_in_name function */
/*
   This function returns a 1 if the input string
   has a dot "." in it.  Else, it returns zero.
*/

int has_dot_in_name(char string[])
{
   int result = 1;
   if(strchr(string, '.') == NULL)
      result = 0;
   return(result);
}  /* ends has_dot_in_name */
/*************************************************/
/*PAGE display_usage function
/*
   display_usage(...

   This function displays the usage or explain 
   information to the screen.

   A. Read all the lines in the input file.
   B. Look for the start marker.
      C. Once you find the start marker, read the
         information.
      D. Display the line as long as it is not 
         the end marker.
      E. If you display a full screen of text, stop
         and wait for a response
      F. If the response is:
         space - show another full screen of text
         return - show one line of text
         Q or q - quit
      G. When you hit the end marker, quit 
         displaying the text you read.
*/

void display_usage(FILE *input_file, 
                   char start[], 
                   char end[])
{
   char *f_result, line[LENGTH];
   int  lines_displayed,
        reading_usage,
        response;

   lines_displayed = 0;

/* A. */
   while(fgets(line, LENGTH+1, input_file)){
/* B. */
      if(strncmp(line, start, 3) == 0){
         reading_usage = 1;
/* C. */
         while(reading_usage){
            f_result = fgets(line, 
                             LENGTH+1, 
                             input_file);
            if(f_result == NULL) 
               reading_usage = 0;

/* D. */
            if((reading_usage == 1)   &&
               (strncmp(line, end, 6) != 0)){
               printf("%s", line);
               lines_displayed++;
/* E. */
               if(lines_displayed >= LPS){
                  response = getchar();
/* F. */
                  if(response == ' ')
                     lines_displayed = 0;
                  if(response == '/n')
                     lines_displayed = LPS-1;
                  if(response == 'Q' ||
                     response == 'q'){
                      exit(20);
                  }  /* ends if response == quit */
               }  /* ends if lines_displayed >= LPS */
            }  /* ends if */
       
/* G. */      
            if(strncmp(line, end, 6) == 0)
               reading_usage = 0;
         }  /* ends while reading_usage */
         
      }  /* ends if found USAGE */

   }  /* ends while fgets */

}  /* ends display_usage */
/*************************************************/
/*PAGE find_and_open_input_file function  */
/*
   find_and_open_input_file(...

   This function attempts to find and open the
   source code file we are examining.  The user
   can enter the source code file name directly
   i.e. file.c file.cpp, etc. or without the 
   extension, i.e. file.  The case where the user
   does not enter the extension is nice because
   the user does not need to know if the source
   code is C, C++, FORTRAN, etc.

   This routine looks to see if the file name has
   a dot (.) in it.  If it does it tries to open
   that file.  If it does not have a dot in it,
   the routine tries several common extenions
   (.c .cpp .f).

   A. If the file name has a dot (.) in it, 
      try to open it.
   B. If no dot in the name, try some common
      file extensions.
      C. Try .c
      D. Try .cpp
      E. Try .f

         You can copy the section of code shown
         and insert the file extension you would
         try.

*/
FILE  *find_and_open_input_file(char input_name[])
{
   char input_file_name[LENGTH],
        temp_string[LENGTH];
   FILE *input_file;
   int  havent_found_file = 1;