redhat man page for ulimit

ULIMIT(3)						     Linux Programmer's Manual							 ULIMIT(3)

NAME
       ulimit - get and set user limits

SYNOPSIS
       #include <ulimit.h>

       long ulimit(int cmd, long newlimit);

DESCRIPTION
       Warning: This routine is obsolete. The include file is no longer provided by glibc.  Use getrlimit(2), setrlimit(2) and sysconf(3) instead.
       For the shell command ulimit, see bash(1).

       The ulimit call will get or set some limit for the current process.  The cmd argument can have one of the following values.

       UL_GETFSIZE
	      Return the limit on the size of a file, in units of 512 bytes.

       UL_SETFSIZE
	      Set the limit on the size of a file.

       3      (Not implemented for Linux.)  Return the maximum possible address of the data segment.

       4      (Implemented but no symbolic constant provided.)	Return the maximum number of files that the calling process can open.

RETURN VALUE
       On success, ulimit returns a nonnegative value.	On error, -1 is returned, and errno is set appropriately.

ERRORS
       EPERM  A non-root process tried to increase a limit.

CONFORMING TO
       SVID.

SEE ALSO
       bash(1), getrlimit(2), setrlimit(2), sysconf(3)

Linux 2.0							    1998-06-12								 ULIMIT(3)