STRTOUL(L)          Linux Programmer's Manual          STRTOUL(L)



NAME
       strtoul,  strtoull  - convert a string to an unsigned long
       integer.

SYNOPSIS
       #include <stdlib.h>

       unsigned long int
       strtoul(const char *nptr, char **endptr, int base);

       unsigned long long int
       strtoull(const char *nptr, char **endptr, int base);

DESCRIPTION
       The strtoul() function converts the initial  part  of  the
       string in nptr to an unsigned long integer value according
       to the given base, which must be between 2 and  36  inclu-
       sive, or be the special value 0.

       The  string  must  begin with an arbitrary amount of white
       space (as determined by isspace(e)) 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 an unsigned
       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, strtoul() stores the address of the
       first invalid character in *endptr.  If there were no dig-
       its at all, strtoul() stores the original value of nptr in
       *endptr  (and  returns 0).  In particular, if *nptr is not
       `\0' but **endptr is `\0' on return, the entire string  is
       valid.

       The  strtoull()  function  works  just  like the strtoul()
       function but returns an unsigned long long integer  value.

RETURN VALUE
       The  strtoul()  function  returns either the result of the
       conversion or, if there was  a  leading  minus  sign,  the
       negation of the result of the conversion, unless the orig-
       inal (non-negated) value would  overflow;  in  the  latter
       case,  strtoul()  returns  ULONG_MAX  and  sets the global
       variable errno to ERANGE.  Precisely the  same  holds  for
       strtoull() (with ULLONG_MAX instead of ULONG_MAX).

ERRORS
       ERANGE The resulting value was out of range.

       EINVAL (not in C99) The given base contains an unsupported
              value.

       The implementation may also set errno to EINVAL in case no
       conversion was performed (no digits seen, and 0 returned).

NOTE
       In locales other than the "C" locale, also  other  strings
       may be accepted.

CONFORMING TO
       strtoul()  conforms to SVID 3, BSD 4.3, ISO 9899 (C99) and
       POSIX, and strtoull() to ISO 9899 (C99) and POSIX-2001.

SEE ALSO
       atof(f), atoi(i), atol(l), strtod(d), strtol(l)



GNU                         2002-02-22                 STRTOUL(L)