Remove trailing blanks,tabs,newlines.

/*remove  trailing blanks, tabs, newlines */
int trim(char s[]){
   int n;

   for (n =strlen(s) -1; n >= 0; n--)
       if(s[n] != ' ' && s[n] != '\t' && s[n] != '\n')
          break;
       s[n + 1] ='\0';
       return n;
}