chrtoi.c revision 34f9b3eef6fdadbda0a846aa4d68691ac40eace5
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1985-2009 AT&T Intellectual Property *
* and is licensed under the *
* Common Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.opensource.org/licenses/cpl1.0.txt *
* (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* David Korn <dgk@research.att.com> *
* Phong Vo <kpv@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* Glenn Fowler
* AT&T Bell Laboratories
*
* convert a 0 terminated character constant string to an int
*/
#include <ast.h>
int
chrtoi(register const char* s)
{
register int c;
register int n;
register int x;
char* p;
c = 0;
for (n = 0; n < sizeof(int) * CHAR_BIT; n += CHAR_BIT)
{
switch (x = *((unsigned char*)s++))
{
case '\\':
x = chresc(s - 1, &p);
s = (const char*)p;
break;
case 0:
return(c);
}
c = (c << CHAR_BIT) | x;
}
return(c);
}