concatenating two strings

Hi,
I am new to c. I was trying to print out this message using pointers.

This is a test
No - it is not a test

This is my code.

Code:

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

int main(){
  char *p = "This is a test";
  printf("%s\n",p);
  strcat(p,"No - this is a test");
  printf("%s\n",p);
}

---

Your help will be appreciated.

not sure, but I think when you use char *p = "hi"; that you make a constant, you can't alter it because the compiler allocated space only for those character, I think...

Quote:

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Originally posted by chrismiceli
not sure, but I think when you use char *p = "hi"; that you make a constant, you can't alter it because the compiler allocated space only for those character, I think...

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Correct. They're using string literals, and as such, you cannot (read: shouldn't try to) modify them.

You'll probably want an array for the first sentence, long enough to hold them both. Either that or do it dynamicly. But an array should suffice for this.

However, if your code actually did work, you would end up with this output:

Quote:

---

This is a test
This is a testNo - this is a test

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strcat adds one string to the end of another. It doesn't replace the first string with the second.

If you really want the first string overwritten, you'd need to use strcpy (or strncpy) or something similar.

Quzah.