#include <stdio.h>

/*
The strdup() function returns a pointer to a new string which is a duplicate of the string s.
Memory for the new string is obtained with malloc(3), and can be freed with free(3).
*/
char *strdup(s)
char *s;
{
    char *p = malloc(strlen(s) + 1);
    if (p) {
      strcpy(p, s);
    }
    return p;
}

/*
Returns a pointer to the first occurrence of str2 in str1, or a null pointer if str2 is not part of str1.
*/
char *strstr(searchee, lookfor)
char *searchee;
char *lookfor;
{
  /* Less code size, but quadratic performance in the worst case.  */
  if (*searchee == 0) {
    if (*lookfor) {
        return (char *) NULL;
    }
    return (char *) searchee;
  }

  while (*searchee) {
    int i;
    i = 0;

    while (1) {
      if (lookfor[i] == 0) {
        return (char *) searchee;
      }

      if (lookfor[i] != searchee[i]) {
        break;
      }
      i++;
    }
    searchee++;
  }
  return (char *) NULL;
}

/*
Replace substr in string with replacement
*/
char *str_replace (string, substr, replacement)
char *string;
char *substr;
char *replacement;
{
  char *tok = NULL;
  char *newstr = NULL;
  char *oldstr = NULL;
  /* if either substr or replacement is NULL, duplicate string a let caller handle it */
  if ( substr == NULL || replacement == NULL ) return strdup (string);
  newstr = strdup(string);
  while ( (tok = strstr(newstr, substr))){
    oldstr = newstr;
    newstr = malloc(strlen(oldstr) - strlen(substr) + strlen(replacement) + 1);
    /*failed to alloc mem, free old string and return NULL */
    if (newstr == NULL ){
      free (oldstr);
      return NULL;
    }
    memcpy(newstr, oldstr, tok - oldstr);
    memcpy(newstr + (tok - oldstr), replacement, strlen(replacement));
    memcpy(newstr + (tok - oldstr) + strlen(replacement), tok + strlen(substr), strlen(oldstr) - strlen(substr) - (tok - oldstr));
    memset(newstr + strlen(oldstr) - strlen(substr) + strlen(replacement) , 0, 1);
    free(oldstr);
  }
  return newstr;
}

/*
Wrap a string at x columns
*/
VOID wrap(out, str, columns)
char *out;
char *str;
int columns;
{
    int len, n, w;
    int wordlen=0;
    int linepos=0;
    int outlen=0;
    char *word;

    len = strlen(str);
    for( n=0; n<=len; n++ )
    {
        if( str[n] == ' ' || str[n] == '\n' || n == len )
        {
            if( linepos > columns )
            {
                out[outlen++] = '\n';
                linepos = wordlen;
            }

            for( w=0; w<wordlen; w++ )
            {
                out[outlen++] = word[w];
                word[w] = '\0';
            }

            if( n == len ) {
                out[outlen] = '\0';
            } else if(str[n] == '\n') {
                out[outlen] = str[n];
                linepos=0;
            } else {
                out[outlen] = ' ';
                linepos++;
            }
            outlen++;
            wordlen=0;
        } else {
            word[wordlen++] = str[n];
            linepos++;
        }
    }
}

main()
{
  char *testStr;
  char *outStr;

  testStr = "Let's see if we can create some new UU functions";
  printf("%s\n", str_replace(testStr, "UU", "string"));
  /*
  testStr = "Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse blandit fermentum";
  wrap(outStr, testStr, 10);
  printf("%s", outStr);
  */

}