strtoul , strtoull , strtoumax , strtouq
- convert a string to an
Vt unsigned long , unsigned long long , uintmax_t ,
or
Vt u_quad_t
integer
LIBRARY
Lb libc
SYNOPSIS
#include <stdlib.h>
#include <limits.h> unsigned long
strtoul (const char * restrict nptr char ** restrict endptr int base); unsigned long long
strtoull (const char * restrict nptr char ** restrict endptr int base);
#include <inttypes.h> uintmax_t
strtoumax (const char * restrict nptr char ** restrict endptr int base);
#include <sys/types.h>
#include <stdlib.h>
#include <limits.h> u_quad_t
strtouq (const char *nptr char **endptr int base);
DESCRIPTION
The
strtoul ();
function
converts the string in
Fa nptr
to an
Vt unsigned long
value.
The
strtoull ();
function
converts the string in
Fa nptr
to an
Vt unsigned long long
value.
The
strtoumax ();
function
converts the string in
Fa nptr
to an
Vt uintmax_t
value.
The
strtouq ();
function
converts the string in
Fa nptr
to a
Vt u_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 an
Vt unsigned long
value in the obvious manner,
stopping at the end of the string
or at the first character that does not produce 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
strtoul ();
stores the address of the first invalid character in
Fa *endptr .
If there were no digits at all, however,
strtoul ();
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
strtoul (,);
strtoull (,);
strtoumax ();
and
strtouq ();
functions
return either the result of the conversion
or, if there was a leading minus sign,
the negation of the result of the conversion,
unless the original (non-negated) value would overflow;
in the latter case,
strtoul ();
returns
ULONG_MAX
strtoull ();
returns
ULLONG_MAX
strtoumax ();
returns
UINTMAX_MAX
and
strtouq ();
returns
ULLONG_MAX
In all cases,
errno
is set to
Er ERANGE .
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).
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
strtoul ();
function
conforms to
St -isoC .
The
strtoull ();
and
strtoumax ();
functions
conform to
St -isoC-99 .
The
BSD Fn strtouq
function is deprecated.
