C - String Manipulation

C strings are null-terminated arrays of char. Use string.h functions carefully to avoid overflows.

Learning Objectives

• Use strlen, strcpy/strncpy, strcat/strncat, strcmp.
• Allocate enough space and include the terminating null.

Examples

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

int main(void) {
  char dst[16] = "Hello";
  const char *src = "World";
  strcat(dst, " ");      // dst = "Hello "
  strncat(dst, src, 5);   // dst = "Hello World"
  printf("%s (%zu)\n", dst, strlen(dst));
}

Common Pitfalls

• Buffer overflows when destination is too small.
• Using strcpy/strcat unsafely; prefer length-bounded variants when possible.