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

PROLOG

       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

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  indi-
       cate 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

       Since  the  ulimit()  function  uses  type long rather than rlim_t, this function is not sufficient for file sizes on many current systems.
       Applications should use the getrlimit() or setrlimit() functions instead of the obsolescent ulimit() function.

RATIONALE

       None.

FUTURE DIRECTIONS

       The ulimit() function may be removed in a future version.

SEE ALSO

       exec, getrlimit(), write()

       The Base Definitions volume of POSIX.1-2008, <ulimit.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol-
       ogy  --	Portable  Operating  System  Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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 Stan-
       dard is the referee document. The original Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE
/The Open Group						       2013								ULIMIT(3P)