Question

after numerous attempts to make my program work I turn to you guys. I want to make a program that counts the numbers of times a specific word has been typed in. That specific word has been specified as an argument and I’m trying to recall it by using argc and argv. Then I want the program to count the number of times I type in a word and to finish I want to be able to type in #EOF so it stops and shows me the result. This is what I have been trying on so far.

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

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

int i=0;
char buf[1026]={'\0'};
char *p="#EOF\n";
fgets(buf, sizeof buf, stdin);

while((strcmp(buf, p) !=0) && (fgets(buf, sizeof buf, stdin) != NULL ))
{

   if(strncmp(buf, argv[1], strlen(argv[1])) == 0)
    {
        i++;
    }
}
printf("%d", i);

return 0;
}

I get no errors at all, but nothing really happens either. I did try to check where the fault lies, and I found out that when I try to display the value of I within the if statement it’s counting very very very fast!

Thanks in advance!

Answer 1

You have an infinite loop.

fgets(buf, 1025, stdin);

In the above line of code, fgets() will take from stdin a string of characters including the newline character and store it into buf.

A simple fix to that is to add the newline character into the string you check against:

char *p="#EOF\n";

---

Other issues:

1)

char buf[1026]; // This should be initialized to an empty string when you start
                // char buf[1026] = {'\0'}; would do it
char *p="#EOF";

while(strcmp(buf, p) !=0) 

2) Because you used a while() loop, and you’re checking before getting any input, you’ll always enter it at least once. This might not be what you wanted to do. A do/while loop, or grabbing the input as the first step would be better.

3) if(strncmp(buf, argv[0], this is checking against the name of your program, if you wanted to check against the first command line argument you wanted argv[1]

4) If you’re trying to check that the first command line argument is the same as what the user is typing you want this:

if(strncmp(buf, argv[1], strlen(argv[1])) == 0)

---

My version of your code that’s working:

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

    int i=0;
    char buf[1026]={'\0'};
    char *p="#EOF\n";
    do
    {
       fgets(buf, 1025, stdin);
       if(strncmp(buf, argv[1], strlen(argv[1])) == 0)
            i++;
    } while (strcmp(buf, p) != 0);
    printf("%d\n", i);
    return 0;
}