NAME

       ulimit - get and set process limits

SYNOPSIS

       #include <ulimit.h>

       long ulimit(int cmd, ...);

DESCRIPTION

       The  ulimit()  function  shall  control  process  limits.  The  process limits that can be
       controlled by this function include the maximum size of a single file that can be  written
       (this  is  equivalent  to using setrlimit() with RLIMIT_FSIZE). The cmd values, defined in
       <ulimit.h>, include:

       UL_GETFSIZE
              Return the file size limit (RLIMIT_FSIZE) of the process. The  limit  shall  be  in
              units  of  512-byte  blocks and shall be inherited by child processes. Files of any
              size can be read. The return value shall be the integer part of the soft file  size
              limit  divided by 512. If the result cannot be represented as a long, the result is
              unspecified.

       UL_SETFSIZE
              Set the file size limit for output operations of the process to the  value  of  the
              second  argument,  taken as a long, multiplied by 512. If the result would overflow
              an rlim_t, the actual value set is unspecified. Any process may  decrease  its  own
              limit,  but  only a process with appropriate privileges may increase the limit. The
              return value shall be the integer part of the new file size limit divided by 512.

       The ulimit() function shall not change the setting of errno if successful.

       As all return values are permissible in a successful situation, an application wishing  to
       check  for  error situations should set errno to 0, then call ulimit(), and, if it returns
       -1, check to see if errno is non-zero.

RETURN VALUE

       Upon successful completion, ulimit() shall  return  the  value  of  the  requested  limit.
       Otherwise, -1 shall be returned and errno set to indicate the error.

ERRORS

       The ulimit() function shall fail and the limit shall be unchanged if:

       EINVAL The cmd argument is not valid.

       EPERM  A  process  not  having  appropriate  privileges attempts to increase its file size
              limit.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       getrlimit() , setrlimit() , write() , the Base Definitions volume of IEEE Std 1003.1-2001,
       <ulimit.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 .