NAME

       atoi - convert a string to an integer

SYNOPSIS

       #include <stdlib.h>

       int atoi(const char *str);

DESCRIPTION

       The call atoi(str) shall be equivalent to:

              (int) strtol(str, (char **)NULL, 10)

       except  that  the  handling  of  errors  may  differ. If the value cannot be represented, the behavior is
       undefined.

RETURN VALUE

       The atoi() function shall return the converted value if the value can be represented.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

   Converting an Argument
       The following example checks for proper usage of the program. If there is an  argument  and  the  decimal
       conversion  of  this  argument  (obtained  using  atoi()) is greater than 0, then the program has a valid
       number of minutes to wait for an event.

              #include <stdlib.h>
              #include <stdio.h>
              ...
              int minutes_to_event;
              ...
              if (argc < 2 || ((minutes_to_event = atoi (argv[1]))) <= 0) {
                 fprintf(stderr, "Usage: %s minutes\n", argv[0]); exit(1);
              }
              ...

APPLICATION USAGE

       The atoi() function is subsumed by strtol() but is retained because it is used  extensively  in  existing
       code.  If  the number is not known to be in range, strtol() should be used because atoi() is not required
       to perform any error checking.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       strtol() , 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                                               ATOI(P)