## table of contents

STRTOL(3) | Linux Programmer's Manual | STRTOL(3) |

# NAME¶

strtol - convert a string to a long integer.

# SYNOPSIS¶

#include <stdlib.h>long int strtol(const char *nptr, char **endptr, intbase);

# DESCRIPTION¶

The **strtol()** function converts the string in *nptr* to
a long integer value according to the given *base*, which must be
between 2 and 36 inclusive, or be the special value 0.

The string must begin with an arbitrary amount of white space (as
determined by isspace(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 int 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 not NULL, **strtol()** stores the address
of the first invalid character in **endptr*. If there were no digits at
all, **strtol()** stores the original value of *nptr* in
**endptr*. (Thus, if **nptr* is not `\0' but ***endptr* is
`\0' on return, the entire string is valid.)

# RETURN VALUE¶

The **strtol()** function 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.

# CONFORMING TO¶

SVID 3, BSD 4.3, ISO 9899

# SEE ALSO¶

# BUGS¶

Ignores the current locale.

10 June 1995 | GNU |