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UbixOS / Dump / hybos / lib / string / strrev.c
@cwolsen cwolsen on 31 Oct 2018 1014 bytes Big Dump
/***
*strrev.c - reverse a string in place
*
*       Copyright (c) 1985-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       defines _strrev() - reverse a string in place (not including
*       '\0' character)
*
*******************************************************************************/

/***
*char *_strrev(string) - reverse a string in place
*
*Purpose:
*       Reverses the order of characters in the string.  The terminating
*       null character remains in place.
*
*Entry:
*       char *string - string to reverse
*
*Exit:
*       returns string - now with reversed characters
*
*Exceptions:
*
*******************************************************************************/

char *_strrev(char *string)
{
	char *start = string;
	char *left = string;
	char ch;

	while(*string++);                 /* find end of string */

	string -= 2;

	while(left < string)
	{
		ch = *left;
		*left++ = *string;
		*string-- = ch;
	}

	return start;
}