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


int main(int argc, char **argv) {
    FILE *file;
    file = fopen(argv[1], "r");
    char buf[600];
    char *pos;
    pid_t parent = fork();
    if(parent == 0) {
        while (fgets(buf, sizeof(buf), file)) {
            if ((pos=strchr(buf, 'n')))
                *pos = '';
            printf("%sn", buf);

        }
        return(0);
    }
    wait(NULL);
    return(0);

}

a
b
c

$ gcc -Wall above.c
$ ./a.out
b
a
c