strtol

Chris Torek chris at mimsy.UUCP
Tue Jun 20 21:50:16 AEST 1989


In article <13949 at dartvax.Dartmouth.EDU> pete at eleazar.dartmouth.edu
(Peter Robert Schmitt) writes:
>I am looking for any info on the function strtol().  I can't seem to
>find it in the man pages on my BSD4.3.  Any help appreciated.

You will find neither information nor source---4BSD does (or rather,
`did') not have strtol(), nor strtoul().

Here they are.  These have been tested, although I cannot recall
how strenuously.  (As you can see by the copyright date, I wrote them
last year.  Why Copyright Regents of UC, rather than UM?  Their
license agreement already exists.)

You will have to replace the `#include <limits.h>' line, e.g., with

	#define	LONG_MIN	(-2147483647L - 1)
	 /* cannot use `-2147483648' as the type of the result is unsigned */
	#define	LONG_MAX	2147483647L
	#define	ULONG_MAX	((unsigned long)4294967295)
	 /* old BSD compiler does not have UL suffix */

although I am no longer sure as to whether the types here are correct
(I seem to recall something about `removing suffixes from limits.h
definitions').  In any case, strto*.c below do not depend on the types
in limits.h, just the values.

: Run this shell script with "sh" not "csh"
PATH=/bin:/usr/bin:/usr/ucb:/etc:$PATH
export PATH
all=false
if [ x$1 = x-a ]; then
	all=true
fi
echo Extracting strtol.c
sed 's/^X//' <<'//go.sysin dd *' >strtol.c
X/*
X * Copyright (c) 1988 Regents of the University of California.
X * All rights reserved.  The Berkeley software License Agreement
X * specifies the terms and conditions for redistribution.
X */
X
X#if defined(LIBC_SCCS) && !defined(lint)
Xstatic char sccsid[] = "%W% (Berkeley) %G%";
X#endif /* LIBC_SCCS and not lint */
X
X#include <limits.h>
X#include <ctype.h>
X#include <errno.h>
X
Xint	errno;
X
X/*
X * Convert a string to a long integer.
X *
X * Ignores `locale' stuff.  Assumes that the upper and lower case
X * alphabets and digits are each contiguous.
X */
Xlong
Xstrtol(nptr, endptr, base)
X	char *nptr, **endptr;
X	register int base;
X{
X	register char *s = nptr;
X	register unsigned long acc;
X	register int c;
X	register unsigned long cutoff;
X	register int neg = 0, any, cutlim;
X
X	/*
X	 * Skip white space and pick up leading +/- sign if any.
X	 * If base is 0, allow 0x for hex and 0 for octal, else
X	 * assume decimal; if base is already 16, allow 0x.
X	 */
X	do {
X		c = *s++;
X	} while (isspace(c));
X	if (c == '-') {
X		neg = 1;
X		c = *s++;
X	} else if (c == '+')
X		c = *s++;
X	if ((base == 0 || base == 16) &&
X	    c == '0' && (*s == 'x' || *s == 'X')) {
X		c = s[1];
X		s += 2;
X		base = 16;
X	}
X	if (base == 0)
X		base = c == '0' ? 8 : 10;
X
X	/*
X	 * Compute the cutoff value between legal numbers and illegal
X	 * numbers.  That is the largest legal value, divided by the
X	 * base.  An input number that is greater than this value, if
X	 * followed by a legal input character, is too big.  One that
X	 * is equal to this value may be valid or not; the limit
X	 * between valid and invalid numbers is then based on the last
X	 * digit.  For instance, if the range for longs is
X	 * [-2147483648..2147483647] and the input base is 10,
X	 * cutoff will be set to 214748364 and cutlim to either
X	 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
X	 * a value > 214748364, or equal but the next digit is > 7 (or 8),
X	 * the number is too big, and we will return a range error.
X	 *
X	 * Set any if any `digits' consumed; make it negative to indicate
X	 * overflow.
X	 */
X	cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
X	cutlim = cutoff % (unsigned long)base;
X	cutoff /= (unsigned long)base;
X	for (acc = 0, any = 0;; c = *s++) {
X		if (isdigit(c))
X			c -= '0';
X		else if (isalpha(c))
X			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
X		else
X			break;
X		if (c >= base)
X			break;
X		if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
X			any = -1;
X		else {
X			any = 1;
X			acc *= base;
X			acc += c;
X		}
X	}
X	if (any < 0) {
X		acc = neg ? LONG_MIN : LONG_MAX;
X		errno = ERANGE;
X	} else if (neg)
X		acc = -acc;
X	if (endptr != 0)
X		*endptr = any ? s - 1 : nptr;
X	return (acc);
X}
//go.sysin dd *
if [ `wc -c < strtol.c` != 2648 ]; then
	made=false
	echo error transmitting strtol.c --
	echo length should be 2648, not `wc -c < strtol.c`
else
	made=true
fi
if $made; then
	chmod 644 strtol.c
	echo -n '	'; ls -ld strtol.c
fi
echo Extracting strtoul.c
sed 's/^X//' <<'//go.sysin dd *' >strtoul.c
X/*
X * Copyright (c) 1988 Regents of the University of California.
X * All rights reserved.  The Berkeley software License Agreement
X * specifies the terms and conditions for redistribution.
X */
X
X#if defined(LIBC_SCCS) && !defined(lint)
Xstatic char sccsid[] = "%W% (Berkeley) %G%";
X#endif /* LIBC_SCCS and not lint */
X
X#include <limits.h>
X#include <ctype.h>
X#include <errno.h>
X
Xint	errno;
X
X/*
X * Convert a string to an unsigned long integer.
X *
X * Ignores `locale' stuff.  Assumes that the upper and lower case
X * alphabets and digits are each contiguous.
X */
Xunsigned long
Xstrtoul(nptr, endptr, base)
X	char *nptr, **endptr;
X	register int base;
X{
X	register char *s = nptr;
X	register unsigned long acc;
X	register int c;
X	register unsigned long cutoff;
X	register int neg = 0, any, cutlim;
X
X	/*
X	 * See strtol for comments as to the logic used.
X	 */
X	do {
X		c = *s++;
X	} while (isspace(c));
X	if (c == '-') {
X		neg = 1;
X		c = *s++;
X	} else if (c == '+')
X		c = *s++;
X	if ((base == 0 || base == 16) &&
X	    c == '0' && (*s == 'x' || *s == 'X')) {
X		c = s[1];
X		s += 2;
X		base = 16;
X	}
X	if (base == 0)
X		base = c == '0' ? 8 : 10;
X	cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
X	cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
X	for (acc = 0, any = 0;; c = *s++) {
X		if (isdigit(c))
X			c -= '0';
X		else if (isalpha(c))
X			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
X		else
X			break;
X		if (c >= base)
X			break;
X		if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
X			any = -1;
X		else {
X			any = 1;
X			acc *= base;
X			acc += c;
X		}
X	}
X	if (any < 0) {
X		acc = ULONG_MAX;
X		errno = ERANGE;
X	} else if (neg)
X		acc = -acc;
X	if (endptr != 0)
X		*endptr = any ? s - 1 : nptr;
X	return (acc);
X}
//go.sysin dd *
if [ `wc -c < strtoul.c` != 1697 ]; then
	made=false
	echo error transmitting strtoul.c --
	echo length should be 1697, not `wc -c < strtoul.c`
else
	made=true
fi
if $made; then
	chmod 644 strtoul.c
	echo -n '	'; ls -ld strtoul.c
fi
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris at mimsy.umd.edu	Path:	uunet!mimsy!chris



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