xoverflowing-strncmp.c

#include <string.h> //declares strcpy and strlength and strcmp

#include <stdio.h>
int CodeBook_check(char[], int, char[][6], int); /*function declaration*/

int main (int argc, char *argv[])
{
    FILE * myfile;//make a file name variable
    if (argv==0) //choosing between stdin and file
    {
        myfile = stdin;//if stdin has input
    }
    else
    {
        myfile=fopen("text.txt", "r"); //if no stdin, open file
    }

    char st[361]; //declare the character string
    int i = 0, j=1; //declare variables
    char z='!';
    z--;

    int count = 0;  // create a count, count will tell me how many codebook
    int end_count = 0, u=0;//declare variable end_count
    int codebook =0;//declare variable codebook
    char CodeBook[90][6]; //declare array codebook

    while (fgets(st, 6, myfile)!=0) //this while loop gets the characters 5 at a time/
    {
        u=j;// setting up a variable for comparison
        j = CodeBook_check(st, z, CodeBook, j); //this sub routine checks the string to see if there is a previous entry
        if (j!=u) //if the code has incremented
        {
            //printf("%d", j);// this is just checking that j is incrementing
            z++;
            codebook +=1;
        }
        count +=1;
        if (count>=90)
        {
            while (fgets(st, 6, myfile)!=0)//this while loop gets the characters 5 at a time/
            {
                printf("%s", st);
                end_count+=strlen(st);
                codebook+=strlen(st);
            }
        }
        end_count+=strlen(st);
    }

    if (!(st[i] == '\n')) //this is a statement added to check for an empty file.
    {
        printf("\n"); //if there is one, it prints a null
    }
    fclose(myfile);
    printf("%d %d %d", end_count, count, codebook);

    return 0;
}

/*This codebook subroutine checks the letters of the string against all existing
strings in the codebook to see if there is a match. if so, it inserts the exhisting code. if not, it
creates a new code*/

int CodeBook_check(char st[], int z, char CodeBook[][6], int j)
{
    int i=0;//declare a counter for the for loop
    int f=strlen(st); // find string length for the strncpy and for loop
    int p; // declare variable p for the for loop counter
    for (i=0; i<j; i++)
    {
        if (strncmp(CodeBook[i], st, f)==0) //if string compare is the same
        {
            z-=i;//adjust the z value to output the appropiate symbol
            printf("%c", z);
            return j; //return the new z value
        }
    }
    printf("%c", z);
    strncpy(CodeBook[j], st, f); //add word to code book
    j++; //increment codebook pointer
    return j;
}