while (buf[i] != NULL)

// includes
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

// defines
#define max             50

int main(int argc, char *argv[])
{
        char    *buf[max];
        char    *temp[max];
        char    *ptr;
        int     *infile;
        int     n;
        int     i = 0;
        //int     j = 0;
        int     count = 0;              // track line number
        int     occurences = 0;         // track # of occurences
        int     offsetSum = 0;          // track file offset position

        if (argc != 3)
        {
                printf("usage: ./mygrep pattern filename\n");
                exit(1);
        }

        if ((infile = open(argv[2], O_RDONLY)) == -1)
        {
                printf("Unable to open file: %s\n", argv[2]);
                exit(1);
        }

        memset(temp, '\0', max);                // set for first use

        while ((n = read(infile, buf, max)) > 0 /*&& j < 10*/)  // while !EOF
        {
                count++;        // keep up with line number
                while (buf[i] != NULL)                                  // while in buf & not end of line
                {
                        temp[i] = buf[i];                               // copy one char at time into temp
                        i++;
                        offsetSum++;
                }
                if ((ptr = strstr(temp, argv[1])) != NULL);             // if pattern found
                {
                        printf("%s: %d %s\n", argv[2], count, temp);
                        occurences++;
                }

                if (lseek(infile, offsetSum, SEEK_SET) < 0)             // reset file position for
                        error("Error while reading file: ", infile);    // next read
                i = 0;                          // reset for next use
                memset(temp, '\0', max);        // reset for next use
                //j++;
        }
        printf("Number of occurences of %s : %d\n", argv[1], occurences);
        close(infile);
        return 0;
}