strtol

STRTOL(3)		  Linux Programmer’s Manual		    STRTOL(3)



NAME
       strtol, strtoll, strtoq - convert a string to a long integer

SYNOPSIS
       #include <stdlib.h>

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

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

DESCRIPTION
       The  strtol() function converts the initial part of the string in nptr
       to a long integer value according to the given  base,  which  must  be
       between 2 and 36 inclusive, or be the special value 0.

       The  string  must  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’ pre-
       fix, 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 a 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,  strtol()	 stores	 the  address  of  the	first
       invalid	character  in  *endptr.	 If there were no digits at all, str-
       tol() 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 strtoll() function works  just  like	 the  strtol()	function  but
       returns a long long integer value.

RETURN VALUE
       The strtol() function returns the result of the conversion, unless the
       value would underflow or overflow.  If an underflow  occurs,  strtol()
       returns	LONG_MIN.   If an overflow occurs, strtol() returns LONG_MAX.
       In both cases, errno is set to ERANGE.  Precisely the same  holds  for
       strtoll()  (with	 LLONG_MIN  and	 LLONG_MAX  instead  of	 LONG_MIN and
       LONG_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).

NOTES
       In  locales  other  than	 the  "C"  locale,  also other strings may be
       accepted.  (For example, the thousands separator of the current locale
       may be supported.)

       BSD also has

	   quad_t
	   strtoq(const char *nptr, char **endptr, int base);

       with  completely	 analogous  definition.	 Depending on the wordsize of
       the current architecture, this may be equivalent to  strtoll()  or  to
       strtol().

CONFORMING TO
       strtol()	 conforms  to  SVID 3, BSD 4.3, ISO 9899 (C99) and POSIX, and
       strtoll() to ISO 9899 (C99) and POSIX 1003.1-2001.

SEE ALSO
       atof(3), atoi(3), atol(3), strtod(3), strtoul(3)



GNU				  2002-05-30			    STRTOL(3)