xref: /original-bsd/lib/libc/stdlib/strtol.3 (revision 972e85c3)
Copyright (c) 1990 The Regents of the University of California.
All rights reserved.

This code is derived from software contributed to Berkeley by
Chris Torek.

%sccs.include.redist.man%

@(#)strtol.3 5.1 (Berkeley) 05/15/90

STRTOL 3 ""
C 7
NAME
strtol - convert a string to a long integer
SYNOPSIS
#include <stdlib.h>

#include <limits.h>

"long strtol(char *nptr, char **endptr, int base);

DESCRIPTION
Strtol converts the string in nptr to a long value according to the given base , which must be between 2 and 36 inclusive, or be the special value 0.

The string may begin with an arbitrary amount of white space (as determined by isspace ; see ctype (3)), followed by a single optional `+' or `-' sign. If base is zero or 16, the string may then include a `0x' prefix, and the number will be read in base 16; otherwise, a zero base is taken as 10 (decimal) unless the next character is `0', in which case it is taken as 8 (octal).

The remainder of the string is converted to a long value in the obvious manner, stopping at the first character which is not a valid digit in the given base. (In bases above 10, the letter `A' in either upper or lower case represents 10, `B' represents 11, and so forth, with `Z' representing 35.)

If endptr is non nil, strtol stores the address of the first invalid character in *endptr . If there were no digits at all, however, strtol stores the original value of nptr in *endptr . (Thus, if *nptr is not '\e0' but **endptr is '\e0' on return, the entire string was valid.)

RETURN VALUE
Strtol returns the result of the conversion, unless the value would underflow or overflow. If an underflow occurs, strtol returns LONG_MIN . If an overflow occurs, strtol returns LONG_MAX . In both cases, errno is set to ERANGE .
ERRORS

[ERANGE] The given string was out of range; the value converted has been clamped.

SEE ALSO
atof(3), atoi(3), atol(3), strtod(3), strtoul(3)
STANDARDS
Strtol conforms to ANSI X3.159-1989 (``ANSI C'').
BUGS
Ignores the current locale.