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unlimit


NAME
     limit, ulimit, unlimit - set or get limitations on the  sys-
     tem resources available to the current shell and its descen-
     dents

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  speci-
     fies  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.

     -h       Use hard limits instead of the current limits. Hard
              limits  impose  a  ceiling  on  the  values  of the
              current limits. Only the privileged 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 filesystem (see df(1M)).


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



     stacksize       Maximum stack  size  for  the  process.  The
                     default stack size is 2**64.



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



     descriptors     Maximum number of file descriptors. 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.



     memorysize      Maximum size of virtual memory.



     limit is a number, with an optional scaling factor, as  fol-
     lows:

     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 lim-
     its. 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 can-
     not 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.

  Per-Shell Memory Parameters
     The heapsize, datasize, and  stacksize  parameters  are  not
     system  tunables.  The only controls for these are hard lim-
     its, set in a shell startup file, or system-wide  soft  lim-
     its,  which, for the current version of the Solaris OS, is 2
    **64bytes.

OPTIONS
     The following option is supported by ulimit:

     -f       Sets (or reports, 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

     The following example limits the stack  size  to  512  kilo-
     bytes:

     example% ulimit -s 512
     example% 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

     The following command limits the number of file  descriptors
     to 12:
     example$ ulimit -n 12
     example$ 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

     The following command limits the size of a  core  dump  file
     size to 0 kilobytes:

     example% limit coredumpsize 0
     example% 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

     The following command removes the above limitation  for  the
     core file size:

     example% unlimit coredumpsize
     example% 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: LANG, LC_ALL,
     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  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcsu                     |
    |_____________________________|_____________________________|
    | Interface Stability         | Standard                    |
    |_____________________________|_____________________________|


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










Man pages from Solaris 10 Update 8. See docs.sun.com and www.oracle.com for further documentation and Solaris information.
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