reading a text file printing line number

Hi guys i have done the following code and basically im trying to read a file and put line numbers to every line in the file. How would i read it in line by line then putting line numbers next to it. I have to use an Int for the lineNo's and int input_char variables i cant change them so im having difficulty finding a correct function to read them line by line which takes an int and not a char.

Code:

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv)
{

    int line_no = 1;
    int input_char;
    FILE *fp;

    if(argc !=2) /* check for 2 arguments*/
    {

      fprintf(stderr, "invalid usage :%s\n", argv[0]);
      return 1; /* stop processing if failes */

    }

    if((fp = fopen(argv[1], "r")) == NULL) 
    /* opens file for reading and checks if it exists */
    {
     
     fprintf(stderr, "invalid usage: %s\n", argv[0]);
     return 1; /* stop processing if fails*/

    }

          printf("dude\n");

    while(fgetc(fp)!=NULL)
    {


          fprintf(fp, "%s", input_char);
          line_no++;

    }

       
    

    fclose(fp);



    return EXIT_SUCCESS;

}

> while(fgetc(fp)!=NULL)
Read up on
- what fgetc() returns
- how to assign a value to say input_char

> fprintf(fp, "%s", input_char);
Read your printf manual page again.

Code:

while(fgetc(fp)!=NULL)

Look up the return value of fgetc. You might want to store the character returned in your input_char if you plan to write it.

Code:

fprintf(fp, "%s", input_char);

%s is used with a string, not an int. Use %c to print a character. Trying to write to the file you are reading from is not a good idea, though.

So what im basically tryin to do is read the file using an int variable input_char then listing line numbers on each then print it out to standard out.

eg
1 abc
2 abc
3 abc

The people that replied understand what you're trying to do. They're waiting for you to fix the issues they pointed out and for you to make a sincere attempt at doing it first.