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limit(1)			 User Commands			      limit(1)

NAME
       limit, ulimit, unlimit -	set or get limitations on the system resources
       available to the	current	shell and its descendents

SYNOPSIS
       /usr/bin/ulimit [-f] [blocks]

   sh
       ulimit [	- [HS] [ a | cdfnstv]]

       ulimit [	- [HS] [ c | d | f | n | s | t | v]] limit

   csh
       limit [-h] [ resource [limit]]

       unlimit [-h] [resource]

   ksh
       ulimit [-HSacdfnstv] [limit]

DESCRIPTION
   /usr/bin/ulimit
       The ulimit utility sets or reports the file-size	writing	limit  imposed
       on  files  written  by  the shell and its child processes (files	of any
       size may	be read). Only	a  process  with  appropriate  privileges  can
       increase	the limit.

   sh
       The Bourne shell	built-in function, ulimit, prints or sets hard or soft
       resource	limits.	These limits are described in getrlimit(2).

       If limit	is not present,	ulimit prints the specified limits. Any	number
       of  limits may be printed at one	time. The -a option prints all limits.

       If limit	is present, ulimit sets	the  specified	limit  to  limit.  The
       string  unlimited  requests  the	largest	valid limit. Limits may	be set
       for only	one resource at	a time.	Any user may set a soft	limit  to  any
       value  below  the  hard	limit. Any user	may lower a hard limit.	Only a
       super-user may raise a hard limit; see su(1M).

       The -H option specifies a hard limit. The -S option  specifies  a  soft
       limit.  If neither option is specified, ulimit will set both limits and
       print the soft limit.

       The following options specify the  resource  whose  limits  are	to  be
       printed	or  set.  If  no  option  is specified,	the file size limit is
       printed or set.

       -c    maximum core file size (in	512-byte blocks)

       -d    maximum size of data segment or heap (in kbytes)

       -f    maximum file size (in 512-byte blocks)

       -n    maximum file descriptor plus 1

       -s    maximum size of stack segment (in kbytes)

       -t    maximum CPU time (in seconds)

       -v    maximum size of virtual memory (in	kbytes)

   csh
       The C-shell built-in function, limit, limits  the  consumption  by  the
       current	process	 or any	process	it spawns, each	not to exceed limit on
       the specified resource. If limit	is omitted, print the  current	limit;
       if resource is omitted, display all limits. (Run	the sysdef(1M) command
       to obtain the maximum possible limits  for  your	 system.   The	values
       reported	are in hexadecimal, but	can be translated into decimal numbers
       using the bc(1) command).

       -h    Use hard limits instead of	the current limits. Hard limits	impose
	     a	ceiling	 on  the values	of the current limits. Only the	privi-
	     leged user	may raise the hard limits.

       resource	is one of:

       cputime
	     Maximum CPU seconds per process.

       filesize
	     Largest single file allowed; limited to the size of the  filesys-
	     tem (see df(1M)).

       datasize
	     The maximum size of a process's heap in kilobytes.

       stacksize
	     Maximum stack size	for the	process	(see swap(1M)).

       coredumpsize
	     Maximum  size  of a core dump (file). This	is limited to the size
	     of	the filesystem.

       descriptors
	     Maximum number of file descriptors	(run sysdef()).

       memorysize
	     Maximum size of virtual memory.

       limit is	a number, with an optional scaling factor, as follows:

       nh    Hours (for	cputime).

       nk    n kilobytes. This is the default for all but cputime.

       nm    n megabytes or minutes (for cputime).

       mm:ss Minutes and seconds (for cputime).

       unlimit removes a limitation on resource. If no resource	is  specified,
       then  all  resource limitations are removed. See	the description	of the
       limit command for the list of resource names.

       -h    Remove corresponding hard limits. Only the	privileged user	may do
	     this.

   ksh
       The  Korn shell built-in	function, ulimit, sets or displays  a resource
       limit. The available resources limits are listed	below. Many systems do
       not  contain  one  or  more of these limits.  The limit for a specified
       resource	is set when limit is specified.	The value of limit  can	 be  a
       number  in  the	unit  specified	below with each	resource, or the value
       unlimited. The -H and -S	flags specify whether the hard	limit  or  the
       soft  limit  for	 the  given  resource  is  set.	A hard limit cannot be
       increased once it is set. A soft	limit can be increased up to the value
       of  the	hard limit.  If	neither	the -H or -S options is	specified, the
       limit applies to	both. The current resource limit is printed when limit
       is omitted. In this case, the soft limit	is printed unless -H is	speci-
       fied. When more than one	resource is specified, then the	limit name and
       unit is printed before the value.

       -a    Lists all of the current resource limits.

       -c    The number	of 512-byte blocks on the size of core dumps.

       -d    The number	of K-bytes on the size of the data area.

       -f    The number	of 512-byte blocks on files written by child processes
	     (files of any size	may be read).

       -n    The number	of file	descriptors plus 1.

       -s    The number	of K-bytes on the size of the stack area.

       -t    The number	of seconds (CPU	time) to be used by each process.

       -v    The number	of K-bytes for virtual memory.

       If no option is given, -f is assumed.

OPTIONS
       The following option is supported by ulimit:

       -f    Set (or report, if	no blocks operand is present), the  file  size
	     limit in blocks. The -f option is also the	default	case.

OPERANDS
       The following operand is	supported by ulimit:

       blocks
	     The  number of 512-byte blocks to use as the new file size	limit.

EXAMPLES
   /usr/bin/ulimit
       Example 1:  Limiting the	stack size

       To limit	the stack size to 512 kilobytes:

       % ulimit	-s 512
       % ulimit	-a
       % time(seconds)	       unlimited
       file(blocks)	       100
       data(kbytes)	       523256
       stack(kbytes)	       512
       coredump(blocks)	       200
       nofiles(descriptors)    64
       memory(kbytes)	       unlimited

   sh/ksh
       Example 2:  Limiting the	number of file descriptors

       To limit	the number of file descriptors to 12:

       $ ulimit	-n 12
       $ ulimit	-a
       time(seconds)		unlimited
       file(blocks)		41943
       data(kbytes)		523256
       stack(kbytes)		8192
       coredump(blocks)		200
       nofiles(descriptors)	12
       vmemory(kbytes)		unlimited

   csh
       Example 3: Limiting the core dump file size

       To limit	the size of a core dump	file size to 0 kilobytes:

       % limit coredumpsize 0
       % limit
       cputime		       unlimited
       filesize		       unlimited
       datasize		       523256 kbytes
       stacksize	       8192 kbytes
       coredumpsize	       0 kbytes
       descriptors	       64
       memorysize	       unlimited

       Example 4: Removing the limitation for core file	size

       To remove the above limitation for the core file	size:

       % unlimit coredumpsize
       % limit
       cputime		       unlimited
       filesize		       unlimited
       datasize		       523256 kbytes
       stacksize	       8192 kbytes
       coredumpsize	       unlimited
       descriptors	       64
       memorysize	       unlimited

ENVIRONMENT VARIABLES
       See environ(5) for descriptions of the following	environment  variables
       that  affect  the  execution  of	 ulimit:  LC_CTYPE,  LC_MESSAGES,  and
       NLSPATH.

EXIT STATUS
       The following exit values are returned by ulimit:

       0     Successful	completion.

       >0    A request for a higher limit was rejected or an error occurred.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       bc(1), csh(1), ksh(1), sh(1),  df(1M),  su(1M),	swap(1M),  sysdef(1M),
       getrlimit(2), attributes(5), environ(5)

SunOS 5.9			  26 Jun 1998			      limit(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | EXAMPLES | ENVIRONMENT VARIABLES | EXIT STATUS | ATTRIBUTES | SEE ALSO

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