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strtol(3) - strtol, strtoll, strtoq, strtol, strtoll, strtoq - convert a string to a long integer - man 3 strtol

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



NAME
       strtol, strtoll, strtoq - convert a string(3,n) 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(3,n) in(1,8) 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(3,n)  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(3,n) may then include a `0x' pre-
       fix, and the number will be read(2,n,1 builtins) in(1,8) base 16; otherwise, a zero base  is
       taken  as  10 (decimal) unless the next character is `0', in(1,8) which case
       it is taken as 8 (octal).

       The remainder of the string(3,n) is converted to a long  int  value  in(1,8)  the
       obvious  manner,  stopping  at the first character which is not a valid
       digit in(1,8) the given base.  (In bases above 10, the letter `A' in(1,8)  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(1,8) *endptr.  If there were no digits at all, strtol() stores
       the original value of nptr in(1,8) *endptr (and returns 0).  In  particular,
       if(3,n)  *nptr is not `\0' but **endptr is `\0' on return, the entire string(3,n)
       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(7,n,1 builtins) to ERANGE.  Precisely the  same  holds  for
       strtoll()  (with  LLONG_MIN  and  LLONG_MAX  instead  of  LONG_MIN  and
       LONG_MAX).

ERRORS
       EINVAL (not in(1,8) C99) The given base contains an unsupported value.

       ERANGE The resulting value was out of range.

       The implementation may also set(7,n,1 builtins) errno to EINVAL in(1,8) case  no  conversion
       was performed (no digits seen, and 0 returned).

NOTES
       In  locales  other  than  the  "C"  locale(3,5,7),  also  other strings may be
       accepted.  (For example, the thousands separator of the current  locale(3,5,7)
       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  str-
       tol().

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)

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