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STRTOL(3P)                 POSIX Programmer's Manual                STRTOL(3P)

PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       strtol, strtoll - convert a string to a long integer
SYNOPSIS
       #include <stdlib.h>
       long strtol(const char  *restrict  str,  char  **restrict  endptr,  int
       base);
       long long strtoll(const char *restrict str, char **restrict endptr,
              int base)

DESCRIPTION
       These functions shall convert the initial portion of the string pointed
       to by str to a type long and long  long  representation,  respectively.
       First, they decompose the input string into three parts:
        1. An  initial, possibly empty, sequence of white-space characters (as
           specified by isspace())
        2. A subject sequence interpreted as an integer  represented  in  some
           radix determined by the value of base
        3. A  final  string  of one or more unrecognized characters, including
           the terminating null byte of the input string.
       Then they shall attempt to convert the subject sequence to an  integer,
       and return the result.
       If the value of base is 0, the expected form of the subject sequence is
       that of a decimal constant, octal constant,  or  hexadecimal  constant,
       any  of  which may be preceded by a '+' or '-' sign. A decimal constant
       begins with a non-zero digit, and consists of  a  sequence  of  decimal
       digits.  An  octal  constant consists of the prefix '0' optionally fol-
       lowed by a sequence of the digits '0' to '7' only.  A hexadecimal  con-
       stant  consists  of  the  prefix 0x or 0X followed by a sequence of the
       decimal digits and letters 'a' (or 'A' ) to 'f' (or 'F' )  with  values
       10 to 15 respectively.
       If the value of base is between 2 and 36, the expected form of the sub-
       ject sequence is a sequence of letters and digits representing an inte-
       ger  with  the radix specified by base, optionally preceded by a '+' or
       '-' sign. The letters from 'a' (or 'A' ) to 'z' (or 'Z' ) inclusive are
       ascribed  the  values  10 to 35; only letters whose ascribed values are
       less than that of base are permitted. If the value of base is  16,  the
       characters  0x or 0X may optionally precede the sequence of letters and
       digits, following the sign if present.
       The subject sequence is defined as the longest initial  subsequence  of
       the  input  string,  starting  with the first non-white-space character
       that is of the expected form. The subject  sequence  shall  contain  no
       characters  if the input string is empty or consists entirely of white-
       space characters, or if the first non-white-space  character  is  other
       than a sign or a permissible letter or digit.
       If  the subject sequence has the expected form and the value of base is
       0, the sequence of characters starting with the first  digit  shall  be
       interpreted  as  an  integer  constant. If the subject sequence has the
       expected form and the value of base is between 2 and 36,  it  shall  be
       used  as the base for conversion, ascribing to each letter its value as
       given above. If the subject sequence begins  with  a  minus  sign,  the
       value  resulting from the conversion shall be negated. A pointer to the
       final string shall be stored in the object pointed to by  endptr,  pro-
       vided that endptr is not a null pointer.
       In  other  than  the C  or POSIX  locales, other implementation-defined
       subject sequences may be accepted.
       If the subject sequence is empty or does not have the expected form, no
       conversion  is  performed;  the  value  of  str is stored in the object
       pointed to by endptr, provided that endptr is not a null pointer.
       The strtol() function shall not change the setting of errno if success-
       ful.
       Since  0,  {LONG_MIN} or {LLONG_MIN}, and {LONG_MAX} or {LLONG_MAX} are
       returned on error and are also valid returns on success, an application
       wishing  to check for error situations should set errno to 0, then call
       strtol() or strtoll(), then check errno.
RETURN VALUE
       Upon successful completion, these functions shall return the  converted
       value, if any. If no conversion could be performed, 0 shall be returned
       and errno may be set to [EINVAL].
       If the correct value is outside  the  range  of  representable  values,
       {LONG_MIN},  {LONG_MAX},  {LLONG_MIN}, or {LLONG_MAX} shall be returned
       (according to the sign of the value), and errno set to [ERANGE].
ERRORS
       These functions shall fail if:
       ERANGE The value to be returned is not representable.

       These functions may fail if:
       EINVAL The value of base is not supported.

       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       None.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       isalpha(),  scanf(),  strtod(),  the   Base   Definitions   volume   of
       IEEE Std 1003.1-2001, <stdlib.h>
COPYRIGHT
       Portions  of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE and
       The  Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be  obtained  online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003                           STRTOL(3P)