ulimit(2)                  DG/UX 4.30                   ulimit(2)



     NAME
          ulimit - Get and set user limits.

     SYNOPSIS
          long  ulimit (cmd, newlimit)
             int        cmd;
             long       newlimit;

     PARAMETERS
          cmd            Specifies which of several user limit-related
                         operations to perform.

          newlimit       A argument to the user limit operation.  Its
                         specific meaning depends upon the cmd
                         argument.

     DESCRIPTION
          This system call controls various per-process limits.  The
          cmd argument specifies which of several operations to
          perform as described below:

          1    Get the calling process's file size limit.  The file
               size limit is the maximum logical offset within a file
               at which the process can perform a write operation.
               The limit is in units of 512-byte blocks.  The newlimit
               argument is ignored and need not be present.  This
               option is the same as the hard RLIMIT_FSIZE in
               getrlimit.

          2    Set the file size limit of the process to newlimit.  A
               process may not increase its file size limit unless it
               has an effective-user-id of 0 (that is, is super-user).
               Newlimit may be any positive or negative integer.  This
               option is the same as the hard RLIMIT_FSIZE in
               setrlimit with the soft RLIMIT_FSIZE set to
               RLIM_INFINITY.

          3    Get the maximum possible break value for the calling
               process.  The newlimit argument is ignored and need not
               be present.

          4    Get the maximum number of open files allowed per
               process.

     ACCESS CONTROL
          The following access restrictions apply, depending on the
          value of cmd:

          1    None.

          2    If newlimit is greater than the current value of the
               file size limit, the effective-user-id of the calling



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     ulimit(2)                  DG/UX 4.30                   ulimit(2)



               process must be 0 for the call to succeed.  Otherwise,
               the limit is unchanged and an EPERM error is returned.

          3    None.

          4    None.

     RETURN VALUE
          If cmd has the value 1, the return value is as follows:

          0..FILESIZE    The return value is always the current value
                         of the calling process's file size limit.

          If cmd has the value 2, the return value is as follows:

          0..FILESIZE    Successful completion.  The new file size
                         limit is returned.

          -1             An error occurred.  Error is set to indicate
                         the error.

          If cmd has the value 3, the return value is as follows:

          0..MAXBRK      The return value is always the calling
                         process's maximum possible break value.

          If cmd has the value 4, the return value is as follows:

          NOFILE         The return value is always NOFILE as defined
                         in param.h.

          If cmd is anything other than the above values, -1 is
          returned and errno is set to EINVAL.

     EXCEPTIONS
          Errno may be set to one of the following error codes:

          EPERM          The calling process is trying to increase its
                         file size limit and does not have an
                         effective-user-id of 0.

          EINVAL         The value of cmd was not 1, 2, 3, or 4.

     SEE ALSO
          getrlimit(2), setrlimit(2), brk(2), write(2).










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