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ulimit(3)
NAME
  ulimit - Sets and gets process limits

LIBRARY
  Standard C Library (libc.so, libc.a)

SYNOPSIS
  #include <ulimit.h>

  long int ulimit (
	  int command,
	  ... );

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  ulimit():  XSH4.2

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  command   Specifies the form of control. The command parameter can have the
	    following values:

	    UL_GETFSIZE
		      Returns the soft file size limit of the process. The
		      limit is reported in 512-byte blocks (see the
		      sys/param.h file) and is inherited by child processes.
		      The function can read files of any size.

		      The return value is the integer part of the soft file
		      size limit divided by 512.  If the result cannot be
		      represented as a long int, the result is unspecified.

	    UL_SETFSIZE
		      Sets the hard and soft process file size limit for
		      output operations to the value of the second parameter,
		      taken as a long int value, and returns the new file
		      size limit.  Any process can decrease its own hard
		      limit, but only a process with superuser privileges can
		      increase the limit.

		      The hard and soft file size limits are set to the
		      specified value multiplied by 512. If the result would
		      overflow an rlim_t, the actual value set is
		      unspecified.

	    UL_GETBREAK
		      [Tru64 UNIX]  Returns the maximum possible break value
		      as described in the brk(2) reference page.



DESCRIPTION
  The ulimit() function controls process limits.

  During access to remote files, the process limits of the local node are
  used.

NOTES
  The ulimit() function is implemented with calls to setrlimit(). The two
  interfaces should not be used in the same program. The result of doing so
  is undefined.

RETURN VALUES
  Upon successful completion, ulimit() returns the value of the requested
  limit and does not change the setting of errno.  Otherwise, a value of -1
  is returned, and errno is set to indicate the error.

ERRORS
  If the ulimit() function fails, the limit remains unchanged and errno is
  set to one of the following values:

  [EINVAL]  The command parameter is invalid.

  [EPERM]   A process without appropriate system privileges attempted to
	    increase its file size limit.

  As all return values are permissable 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
  nonzero.

RELATED INFORMATION
  Commands: ulimit(1)

  Functions: brk(2), getrlimit(2), write(2)

  Routines: pathconf(2)

  Standards: standards(5)

Index for Section 3

Alphabetical listing for U

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