illumos-port-bash/lib/sh/uconvert.c

125 lines
2.8 KiB
C

/* uconvert - convert string representations of decimal numbers into whole
number/fractional value pairs. */
/* Copyright (C) 2008,2009,2020 Free Software Foundation, Inc.
This file is part of GNU Bash, the Bourne Again SHell.
Bash is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Bash is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Bash. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "bashtypes.h"
#include "posixtime.h"
#if defined (HAVE_UNISTD_H)
#include <unistd.h>
#endif
#include <stdio.h>
#include "chartypes.h"
#include "shell.h"
#include "builtins.h"
#define DECIMAL '.' /* XXX - should use locale */
#define RETURN(x) \
do { \
if (ip) *ip = ipart * mult; \
if (up) *up = upart; \
if (ep) *ep = p; \
return (x); \
} while (0)
/*
* An incredibly simplistic floating point converter.
*/
static int multiplier[7] = { 1, 100000, 10000, 1000, 100, 10, 1 };
/* Take a decimal number int-part[.[micro-part]] and convert it to the whole
and fractional portions. The fractional portion is returned in
millionths (micro); callers are responsible for multiplying appropriately.
EP, if non-null, gets the address of the character where conversion stops.
Return 1 if value converted; 0 if invalid integer for either whole or
fractional parts. */
int
uconvert(s, ip, up, ep)
char *s;
long *ip, *up;
char **ep;
{
int n, mult;
long ipart, upart;
char *p;
ipart = upart = 0;
mult = 1;
if (s && (*s == '-' || *s == '+'))
{
mult = (*s == '-') ? -1 : 1;
p = s + 1;
}
else
p = s;
for ( ; p && *p; p++)
{
if (*p == DECIMAL) /* decimal point */
break;
if (DIGIT(*p) == 0)
RETURN(0);
ipart = (ipart * 10) + (*p - '0');
}
if (p == 0 || *p == 0) /* callers ensure p can never be 0; this is to shut up clang */
RETURN(1);
if (*p == DECIMAL)
p++;
/* Look for up to six digits past a decimal point. */
for (n = 0; n < 6 && p[n]; n++)
{
if (DIGIT(p[n]) == 0)
{
if (ep)
{
upart *= multiplier[n];
p += n; /* To set EP */
}
RETURN(0);
}
upart = (upart * 10) + (p[n] - '0');
}
/* Now convert to millionths */
upart *= multiplier[n];
if (n == 6 && p[6] >= '5' && p[6] <= '9')
upart++; /* round up 1 */
if (ep)
{
p += n;
while (DIGIT(*p))
p++;
}
RETURN(1);
}