atoi(3p) - phpMan

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