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 .