ACC SHELL

ulimit [ [ -SHacdfilmnpqstvx | -N resource [ limit ] ... ]
       Set  or  display  resource limits of the shell and the processes
       started by the shell.  The value of limit can be a number in the
       unit specified below or the value `unlimited'.  By default, only
       soft limits are manipulated. If the -H flag is  given  use  hard
       limits instead of soft limits.  If the -S flag is given together
       with the -H flag set both hard and soft limits.  If  no  options
       are  used,  the  file  size  limit (-f) is assumed.  If limit is
       omitted  the  current  value  of  the  specified  resources  are
       printed.   When  more  than  one resource values are printed the
       limit name and unit is printed before each value.

       When looping over multiple resources, the shell will abort imme-
       diately  if  it detects a badly formed argument.  However, if it
       fails to set a limit for some other reason it will continue try-
       ing to set the remaining limits.

       -a     Lists all of the current resource limits.
       -c     512-byte blocks on the size of core dumps.
       -d     K-bytes on the size of the data segment.
       -f     512-byte blocks on the size of files written.
       -i     The number of pending signals.
       -l     K-bytes on the size of locked-in memory.
       -m     K-bytes on the size of physical memory.
       -n     open file descriptors.
       -q     Bytes in POSIX message queues.
       -s     K-bytes on the size of the stack.
       -t     CPU seconds to be used.
       -u     processes available to the user.
       -v     K-bytes  on  the size of virtual memory.  On some systems
              this refers to the limit called `address space'.
       -x     The number of locks on files.

       A resource may also be specified by  integer  in  the  form  `-N
       resource', where resource corresponds to the integer defined for
       the resource by the operating system.  This may be used  to  set
       the  limits for resources known to the shell which do not corre-
       spond to option letters.  Such limits will be shown by number in
       the output of `ulimit -a'.

       The  number may alternatively be out of the range of limits com-
       piled into the shell.  The shell will try to read or  write  the
       limit anyway, and will report an error if this fails.