strtol , strtoll , strtoimax , strtoq
- convert a string value to a
Vt long , long long , intmax_t
or
Vt quad_t
integer
LIBRARY
Lb libc
SYNOPSIS
#include <stdlib.h>
#include <limits.h> long
strtol (const char * restrict nptr char ** restrict endptr int base); long long
strtoll (const char * restrict nptr char ** restrict endptr int base);
#include <inttypes.h> intmax_t
strtoimax (const char * restrict nptr char ** restrict endptr int base);
#include <sys/types.h>
#include <stdlib.h>
#include <limits.h> quad_t
strtoq (const char *nptr char **endptr int base);
DESCRIPTION
The
strtol ();
function
converts the string in
Fa nptr
to a
Vt long
value.
The
strtoll ();
function
converts the string in
Fa nptr
to a
Vt long long
value.
The
strtoimax ();
function
converts the string in
Fa nptr
to an
Vt intmax_t
value.
The
strtoq ();
function
converts the string in
Fa nptr
to a
Vt quad_t
value.
The conversion is done according to the given
Fa 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(3))
followed by a single optional
`+'
or
`-'
sign.
If
Fa 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
Fa 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
Vt long , long long , intmax_t
or
Vt quad_t
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
Fa endptr
is not
NULL
strtol ();
stores the address of the first invalid character in
Fa *endptr .
If there were no digits at all, however,
strtol ();
stores the original value of
Fa nptr
in
Fa *endptr .
(Thus, if
Fa *nptr
is not
`\0'
but
Fa **endptr
is
`\0'
on return, the entire string was valid.)
RETURN VALUES
The
strtol (,);
strtoll (,);
strtoimax ();
and
strtoq ();
functions
return the result of the conversion,
unless the value would underflow or overflow.
If no conversion could be performed, 0 is returned and
the global variable
errno
is set to
Er EINVAL
(the last feature is not portable across all platforms).
If an overflow or underflow occurs,
errno
is set to
Er ERANGE
and the function return value is clamped according
to the following table.
Function Ta underflow Ta overflow
Fn strtol Ta LONG_MIN Ta LONG_MAX
Fn strtoll Ta LLONG_MIN Ta LLONG_MAX
Fn strtoimax Ta INTMAX_MIN Ta INTMAX_MAX
Fn strtoq Ta LLONG_MIN Ta LLONG_MAX
ERRORS
Bq Er EINVAL
The value of
Fa base
is not supported or
no conversion could be performed
(the last feature is not portable across all platforms).
Bq Er ERANGE
The given string was out of range; the value converted has been clamped.
The
strtol ();
function
conforms to
St -isoC .
The
strtoll ();
and
strtoimax ();
functions
conform to
St -isoC-99 .
The
BSD Fn strtoq
function is deprecated.
