#define INCL_DOS

#include <os2.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>

#pragma alloc_text(MISC8,stristr,strnstr,strnistr,findstring)


CHAR * stristr (register CHAR *t, CHAR *s) {

  /* case-insensitive strstr() */

  register CHAR *t1,*s1;

  while (*t) {
    t1 = t;
    s1 = s;
    while (*s1) {
      if (toupper (*s1) != toupper (*t))
        break;
      else {
        s1++;
        t++;
      }
    }
    if (!*s1)
      return t1;
    t = t1 + 1;
  }
  return NULL;
}



CHAR * strnistr (register CHAR *t, CHAR *s, LONG len) {

  /* case-insensitive strnstr() */

  register CHAR *s1;
  register LONG  len2;

  len2 = 0;
  while (len > len2) {
    s1 = s;
    while (len2 < len) {
      if (toupper (*s1) != toupper (t[len2]))
        break;
      else {
        len2++;
        s1++;
      }
    }
    if (!*s1)
      return t + (len2 - strlen(s));
    len2++;
  }
  return NULL;
}


CHAR * strnstr (register CHAR *t, CHAR *s, LONG len) {

  /* strnstr() */

  register CHAR *s1;
  register LONG  len2;

  len2 = 0;
  while (len > len2) {
    s1 = s;
    while (len2 < len) {
      if (*s1 != t[len2])
        break;
      else {
        len2++;
        s1++;
      }
    }
    if (!*s1)
      return t + (len2 - strlen(s));
    len2++;
  }
  return NULL;
}


CHAR * findstring (CHAR *findthis, ULONG lenthis, CHAR *findin,
                   ULONG lenin, BOOL sensitive) {

  register CHAR *this,*in;
  register ULONG lenthis2,lenin2;

  if(!findthis || !findin || !lenthis || !lenin)
    return NULL;
  do {
    this = findthis;
    lenthis2 = lenthis;
    in = findin;
    lenin2 = lenin;
    while(lenthis2 && lenin2) {
      if(!sensitive) {
        if(toupper(*this) != toupper(*in))
          break;
        else {
          this++;
          in++;
          lenthis2--;
          lenin2--;
        }
      }
      else {
        if(*this != *in)
          break;
        else {
          this++;
          in++;
          lenthis2--;
          lenin2--;
        }
      }
    }
    if(lenthis2) {
      lenin--;
      findin++;
    }
  } while(lenin && lenthis2);
  return (lenthis2) ? NULL : in - lenthis;
}