Упрощение кода

#include <stdio.h>
#include <string.h>
int main() {
    FILE * fp; //open exists file
    FILE * fn; //open empty file
    char c[1000]; // buffer
    char trigger[] = "o'clock"; // the word before which the characters should be added
    char name [] = "startFile.txt"; // name of source file
    char secondName[] = "newFile.txt"; // name of output file
    fp = fopen (name, "r"); // open only for reading
    if (fp == NULL) { // testing on exists
        printf ( "Error");
        getchar ();
        return 0;
    }
    fn = fopen(secondName, "w"); // open empty file for writing
    if (fn == NULL) { // testing on create
        printf ( "Error");
        getchar ();
        return 0;
    }
    while (fgets(c, 1000, fp)) { // scanning all string in the source
        char *p = strstr(c, trigger);
        if (p) {
            // ok we found the trigger - now we need to search backwards
            // to find the end and then the start of the word before
            while (p>c && p[-1]==' ') p--; // find the end of the word
            memmove(p+1, p, c+999 - p); // make a space for the ]
            *p = ']';
            while (p>c && p[-1]!=' ') p--; // find the start of the word
            memmove(p+1, p, c+999 - p); // make a space for the [
            *p = '[';
        }
        fputs(c, fn); // writing charter from buffer "c" to empty file
    }
    fclose(fp); // closing file
    fclose(fn);
    return 0;
}