_ERROR MESSAGE MANAGEMENT_
by Rohan Douglas

[LISTINÇ ONE]


  /* Include file for macros replacement of erroò function® */

  #define error(m)  _error(__FILE__, __LINE__)

  extern  void      _error(char *, int);


[LISTINÇ TWO]

/* Definition of error function®  */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "error.h"

static int get_err_msg(char *, char *, char *);

void
_error(char *fname, int lno)
{
    char *period;  /* Pointer for file extension */
    char lstr[6];  /* Temp string for file line */
    char key[15];  /* Message key (file:line) */
    char msg[75];  /* Error message from file */

    /* Strip out file extension from file name */
    if ((period = strchr(fname, '.')) != NULL)
        *period = '\0';

    /* Create file:linenumber key */
    sprintf(key, "%s:%s", fname, itoa(lno, lstr,
       10));

    /* Look up error message from file */
    if (!get_err_msg(fname, key, msg))
        /* Not found in file, just print out
         * file:lineno.
         */
        printf("Error [%s]", key);
    else 
        printf("%s [%s]", msg, key);
    return;
} /* error() */

static int
get_err_msg(char *fname, char *key, char *msg)
{
    FILE *fp;      /* Error message file pointer */
    char msg_key[14];/* Key for current line */

    /* Open error file */
    if (!(fp = fopen("error.dat", "r")))
        return FALSE;

    /* Scan file for message */
    while (!feof(fp)) {
        fscanf(fp, " %s ", msg_key);
        fgets(msg, 75, fp);
        if (!strcmpi(key, msg_key))
            break;
    }
Š    fclose(fp);

    /* Return false if message not found */
    if (feof(fp))
        return FALSE;

    /* Remove CR from message string */
    msg[strlen(msg)-1] = '\0';
    return TRUE;
} /* get_err_msg() */


[LISTINÇ THREE]


BEGIN {
    FS = "\"";
    printf("") > "error.txt";
    printf("") > "error.dat";
}
/ *error *\(/ {
    printf("%s :\n", $2) >> "error.txt";
    ind = substr(FILENAME, 0, index(FILENAME, ".")
      - 1);
    printf("%s:%d\t%s\n", ind, NR, $2) >>
      "error.dat";
    getline();
    i = index($0, "/* ");
    if (i) i++;
    while (i) {
        printf("\t%s\n", substr($0, i + 2)) >>
          "error.txt";
        getline();
        if (index($0, "*/")) break;
        i = index($0, "* ");
    }
}


Figure 1: Sample source file with embedded error message and
description. 


#include <stdio.h> 
#include "error.h" 
 
main(int argc, char *argv[]) 
{ 
    if (argc == 1) 
        error("Missing parameters"); 
        /*  No parameters have been passed 
         * to this test program. This error message 
         *  will be displayed as an example if no 
         *  parameters are passed to this test 
         *  program. 
         */
    exit(0);
}



Figure 2: The user manual list resulting from Figure 1.

Missing parameters : 
	 No parameters have been passed to 
	 this test program. This error message 
	 will be displayed as an example if no 
	 parameters are passed to this test 
	 program. 



Figure 3: The message database resulting from Figure 1.


test:8  Missing parameters


Figure 4: The results of the sample program.


Missing parameters [test:8]