text: #include<stdio.h>
  void main() {
    char s1[100] = "programming ", s2[] = "is awesome";
    int len, j;
    len = 0;
    while (s1[len] != '\0') {
      ++len;
    }
  
    // concatenate s2 to s1
    for (j = 0; s2[j] != '\0'; ++j, ++len) {
      s1[len] = s2[j];
    }
  
    // terminating the s1 string
    s1[len] = '\0';
    printf("After concatenation: ");
    puts(s1);
  
  }
  