Ultrix-3.1/src/libPW/substr.c

/**********************************************************************
 *   Copyright (c) Digital Equipment Corporation 1984, 1985, 1986.    *
 *   All Rights Reserved. 					      *
 *   Reference "/usr/src/COPYRIGHT" for applicable restrictions.      *
 **********************************************************************/

static char Sccsid[]="@(#)substr.c 3.0 4/22/86";
/*
	Place the `len' length substring of `as' starting at `as[origin]'
	in `aresult'.
	Return `aresult'.
 
  Note: The copying of as to aresult stops if either the
	specified number (len) characters have been copied,
	or if the end of as is found.
	A negative len generally guarantees that everything gets copied.
*/

char *substr(as, aresult, origin, len)
char *as, *aresult;
int origin;
register unsigned len;
{
	register char *s, *result;

	s = as + origin;
	result = aresult;
	++len;
	while (--len && (*result++ = *s++)) ;
	if (len == 0)
		*result = 0;
	return(aresult);
}