ulimit.3

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3 代码 · 共 59 行

.\" SCCSID: @(#)ulimit.3	2.5	8/18/87
.TH ulimit 3
.SH Name
ulimit \- get and set user limits
.SH Syntax
.nf
.ft B
long ulimit (\fIcmd, newlimit\fP)
int \fIcmd\fP;
long \fInewlimit\fP;
.fi
.SH Description
.NXR "ulimit system call"
.NXR "process" "setting limits"
.NXR "process" "getting limits"
This function provides control over process limits.
An explanation of the 
.I cmd
values follow.
.IP "\fBValue\fP" 8
.B Explanation
.IP "\fB1\fP" 
Get the process's file size limit.
The limit is in units of 512-byte blocks
and is inherited by child processes.
Files of any size can be read.
.IP "\fB2\fP"
Set the process's file size limit to the value of
.I newlimit.
Any process can decrease this limit,
but only a process with an effective user ID
of superuser can increase the limit.
The
.PN ulimit
system call
fails and the limit remains unchanged,
if a process with an effective user ID
other than superuser attempts
to increase its file size limit.
.IP "\fB3\fP"
Get the maximum possible break value.  For further information, see
.MS brk 2 .
.PP
.SH Return Values
Upon successful completion, a nonnegative value is returned.
Otherwise, a value of \-1 is returned, and 
.I errno
is set to indicate the error.
.SH Diagnostics
.TP 15
[EINVAL]
Bad value for \fIcmd\fP.
.TP 15
[EPERM]
The effective user ID
of the calling process is not superuser.
.SH See Also
brk(2), write(2)