strtoul(3) - NetBSD Manual Pages

STRTOUL(3)                NetBSD Programmer's Manual                STRTOUL(3)


NAME

     strtoul, strtoull, strtouq - convert a string to an unsigned long, un-
     signed long long or uquad_t integer


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

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

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

     unsigned long long int
     strtoull(const char *nptr, char **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 nptr to an unsigned long
     int value.  The strtoull() function converts the string in nptr to an
     unsigned long long int value.  The strtouq() function 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 deter-
     mined 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 an unsigned long value in the
     obvious manner, stopping at the end of the string or at the first charac-
     ter 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.)


RETURN VALUES

     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 conver-
     sion, unless the original (non-negated) value would overflow; in the lat-
     ter case, strtoul() returns ULONG_MAX and sets the global variable errno
     to ERANGE.


ERRORS

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


SEE ALSO

     strtol(3) strtoll(3)


STANDARDS

     The strtoul() function conforms to ANSI X3.159-1989 (``ANSI C'').  The
     strtoull() function conforms to ISO/IEC 9899:1999 (``ISO C99'').


BUGS

     Ignores the current locale.

NetBSD 1.5                       March 6, 2000                               2