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NetBSD 6.1.5 - man page for strtoull (netbsd section 3)

STRTOUL(3)			   BSD Library Functions Manual 		       STRTOUL(3)

     strtoul, strtoull, strtoumax, strtouq -- convert a string to an unsigned long, unsigned long
     long, uintmax_t or uquad_t integer

     Standard C Library (libc, -lc)

     #include <stdlib.h>
     #include <limits.h>

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

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

     #include <inttypes.h>

     strtoumax(const char * restrict nptr, char ** restrict endptr, int base);

     #include <sys/types.h>
     #include <stdlib.h>
     #include <limits.h>

     strtouq(const char * restrict nptr, char ** restrict endptr, int base);

     The strtoul() function converts the string in nptr to an unsigned long int value.	The
     strtoull() function converts the string in nptr to an unsigned long long int value.  The
     strtoumax() function converts the string in nptr to an uintmax_t value.  The strtouq() func-
     tion converts the string in nptr to a u_quad_t value.  The conversion is done 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(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

     The remainder of the string is converted to an 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 endptr is non-nil, strtoul() stores the address of the first invalid character in
     *endptr.  If there were no digits at all, however, strtoul() stores the original value of
     nptr in *endptr.  (Thus, if *nptr is not '\0' but **endptr is '\0' on return, the entire
     string was valid.)

     The strtoul() function returns either the result of the conversion or, if there was a lead-
     ing 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, strtouq() returns UQUAD_MAX, and the
     global variable errno is set to ERANGE.

     There is no way to determine if strtoul() has processed a negative number (and returned an
     unsigned value) short of examining the string in nptr directly.  If the base argument is not
     supported then errno is set to EINVAL and the functions return 0.

     If no error occurs, errno is left unchanged.  This behavior (which is unlike most library
     functions) is guaranteed by the pertinent standards.

     Because the return value of strtoul() cannot be used unambiguously to detect an error, errno
     is left unchanged after a successful call.  To ensure that a string is a valid number (i.e.,
     in range and containing no trailing characters), clear errno beforehand explicitly, then
     check it afterwards:

	   char *ep;
	   unsigned long ulval;


	   errno = 0;
	   ulval = strtoul(buf, &ep, 10);
	   if (buf[0] == '\0' || *ep != '\0')
		   goto not_a_number;
	   if (errno == ERANGE && ulval == ULONG_MAX)
		   goto out_of_range;

     This example will accept ``12'' but not ``12foo'' or ``12\n''.  If trailing whitespace is
     acceptable, further checks must be done on *ep; alternately, use sscanf(3).

     [EINVAL]		The base is not between 2 and 36 and does not contain the special value

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

     strtoimax(3), strtol(3), strtoll(3)

     The strtoul() function conforms to ANSI X3.159-1989 (``ANSI C89'').  The strtoull() and
     strtoumax() functions conform to ISO/IEC 9899:1999 (``ISO C99'').

     Ignores the current locale.

BSD					 December 2, 2009				      BSD

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