Question

I’m trying to code a program that will print out a certain number of lines from a text file. I think I have the code to open the file and to scan it for how many lines it has. I’m just having trouble printing out the lines. (For example, printing lines 1 through 10 of a file.)

Should I make all the reading of the file into a separate method?

numLines is declared earlier from user input.
Also I wanted to make the src open from a command line argument. Unsure if that is implemented correctly.

EDIT COMPLETE CODE IM WORKING WITH

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAX 256


int numLines = 0;
int linecount = 0;
FILE *src = NULL;
char b[MAX];
char ch;

void GetArgs (int argc, char **argv){
if(argc != 4 || argc != 2) {
    printf("Error not enough arguments to continue \n", argv[0]);
    exit(-1);

}// end if argc doenst = 4 or 2

if(argc == 2){
    src = fopen( argv[1], "r:");
    numLines=10;

}// end argc = 2

if(argc == 4){
    if (strcmp (argv[1], "-n") !=0 ){
        numLines = atoi (argv[2]);
        src = fopen (argv[3], "r");
        if ( src == NULL){
            fputs ( "Can't open input file." , stdout);
            exit (-1);
        }
        while (NULL != fgets(ch,MAX, src)){
            linecount++;
            fputs(ch, stdout);
            if (linecount == numLines){
                break;
            }
        }

    }//end of nested if
    else (strcmp (argv[2], "-n") !=0 ){
        numLines = atoi (argv[3]);
        src = fopen (argv[1], "r");
        if ( src == NULL){
            fputs ( "Can't open input file." , stdout);
            exit (-1);
        }
        while (NULL != fgets(ch,MAX, src)){
            linecount++;
            fputs(ch, stdout);
            if (linecount == numLines){
                break;
            }
        }            


    }//end of else
}//end if argc == 4

}// end GetArgs


}// end GetArgs


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



GetArgs(argc, argv);

Answer 1

Try this

FILE * src = NULL;
int linecount = 0;
int numLines = 5;
char ch[MAX];

src = fopen( argv[1], "r" );
if ( src == NULL ) {
    fputs( "Can't open input file.", stdout );
    exit(-1);
}

while(NULL != fgets(ch,MAX,src)) {
    linecount++;
    fputs(ch, stdout);

    if (linecount == numLines) {
        break;
    }
}