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

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

       #include <stdlib.h>

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

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

       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, strtol() 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.

       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

       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).

       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

           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  str-

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

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

GNU                               2002-05-30                         STRTOL(3)