Solved

Unseccessful Header file (.h) creation, what's wrong?

Posted on 1998-12-27
4
198 Views
Last Modified: 2010-04-02
I wrote a Program (pro87.c), it works fine.  Then I separated it into two files as a Header (pro86.h) and a Program (pro86.c).  It turned error during making.  Compiler  said "Linker Error: Undifined symbol _main in module c0.ASM.   What's wrong.  It's exactly the same except as two files.

Here is as a single file.  It's O.K.
/*PROGRAM pro87.c */
/* DataBase type determination */
#include<stdio.h>
#include<string.h>
#define UNKNOWN      1   //"Unknown"   /* Data format type */
#define GENBANK 2   //"GenBank"
#define EMBL      3   //"EMBL"
#define PIR            4   //"PIR"
#define PRF            5   //"PRF"
#define SEQDATA 6   //"SeqData"
#define BUFLEN  256   /* maximum length of buffer for string */

char linebuf[BUFLEN];

main(int argc, char *argv[])
{
   int dataType;
   FILE *fp;
   if(argc!=2)
        printf("Usage : pro86 filename\n");
   else
        fp=fopen(argv[1], "r");

   dataType=0;
   while(fgets(linebuf, BUFLEN, fp)!=NULL)
   {
       if (strncmp(linebuf, "LOCUS", 5)==0){
            dataType = GENBANK;      break;
       }else if (strncmp(linebuf, "ID ", 3)==0){
            dataType = EMBL; break;
       }else if (strncmp(linebuf, "ENTRY", 5)==0){
            dataType = PIR;      break;
       }else if (strncmp(linebuf, "CODE", 4)==0){
            dataType = PRF; break;
       }else if (linebuf[0] == '>'){
            dataType = SEQDATA; break;
       }else
            dataType = UNKNOWN;
   }

   if(dataType==1)
        printf("Unknown\n");
   if(dataType==2)
        printf("GenBank\n");
   if(dataType==3)
        printf("EMBL\n");
   if(dataType==4)
        printf("PIR\n");
   if(dataType==5)
        printf("PRF\n");
   if(dataType==6)
        printf("SeqData\n");
   fclose(fp);
   return 0;
}

_______________________________________________________
The above is OK, now separate it to two files.

/* pro86.H  ;   This is a header file. */
/* Data format type */
#define UNKNOWN      1   //"Unknown"
#define GENBANK 2   //"GenBank"
#define EMBL      3   //"EMBL"
#define PIR            4   //"PIR"
#define PRF            5   //"PRF"
#define SEQDATA 6   //"SeqData"
_______________________________________
AND
/* PROGRAM Pro86.c */
/* DataBase type determination */
#include<stdio.h>
#include<string.h>
#include<pro86.h>
#define BUFLEN  256   /* maximum length of buffer*/

char linebuf[BUFLEN];

main(int argc, char *argv[])
{
   int dataType;
   FILE *fp;
   if(argc!=2)
        printf("Usage : pro86 filename\n");
   else
        fp=fopen(argv[1], "r");

   dataType=0;
   while(fgets(linebuf, BUFLEN, fp)!=NULL)
   {
       if (strncmp(linebuf, "LOCUS", 5)==0){
            dataType = GENBANK;      break;
       }else if (strncmp(linebuf, "ID ", 3)==0){
            dataType = EMBL; break;
       }else if (strncmp(linebuf, "ENTRY", 5)==0){
            dataType = PIR;      break;
       }else if (strncmp(linebuf, "CODE", 4)==0){
            dataType = PRF; break;
       }else if (linebuf[0] == '>'){
            dataType = SEQDATA; break;
       }else
            dataType = UNKNOWN;
   }

   if(dataType==1)
        printf("Unknown\n");
   if(dataType==2)
        printf("GenBank\n");
   if(dataType==3)
        printf("EMBL\n");
   if(dataType==4)
        printf("PIR\n");
   if(dataType==5)
        printf("PRF\n");
   if(dataType==6)
        printf("SeqData\n");
   fclose(fp);
   return 0;
}
__________________________________________
These don't compile.  Linker Error!!  Help me.




0
Comment
Question by:mkido
  • 2
4 Comments
 
LVL 6

Expert Comment

by:thresher_shark
ID: 1181084
I betcha this:

#include<pro86.h>

should be

#include "pro86.h"
0
 
LVL 6

Expert Comment

by:thresher_shark
ID: 1181085
Other than that, it looks fine.  I am not sure why it would be saying main is undefined...
0
 
LVL 1

Accepted Solution

by:
issamwd earned 50 total points
ID: 1181086
your problem is Simple

I faced the same problem years ago & the same error was appearing & it drived me mad.

The solution is:

this technique you are using is called separating interface from implementation & this is done by including
the .c or .cpp file in a project that is a must.
then try to compile now.

try that with out adding the header file

thanks

0
 

Author Comment

by:mkido
ID: 1181087
Thank you, all.
I got compilation by deleting header file from the project.
Thanks.
0

Featured Post

What Is Threat Intelligence?

Threat intelligence is often discussed, but rarely understood. Starting with a precise definition, along with clear business goals, is essential.

Join & Write a Comment

Suggested Solutions

Introduction This article is the first in a series of articles about the C/C++ Visual Studio Express debugger.  It provides a quick start guide in using the debugger. Part 2 focuses on additional topics in breakpoints.  Lastly, Part 3 focuses on th…
Basic understanding on "OO- Object Orientation" is needed for designing a logical solution to solve a problem. Basic OOAD is a prerequisite for a coder to ensure that they follow the basic design of OO. This would help developers to understand the b…
The goal of the video will be to teach the user the concept of local variables and scope. An example of a locally defined variable will be given as well as an explanation of what scope is in C++. The local variable and concept of scope will be relat…
The viewer will be introduced to the member functions push_back and pop_back of the vector class. The video will teach the difference between the two as well as how to use each one along with its functionality.

708 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

17 Experts available now in Live!

Get 1:1 Help Now