diff options
author | rgrimes <rgrimes@FreeBSD.org> | 1994-05-27 05:00:24 +0000 |
---|---|---|
committer | rgrimes <rgrimes@FreeBSD.org> | 1994-05-27 05:00:24 +0000 |
commit | be22b15ae2ff8d7fe06b6e14fddf0c5b444a95da (patch) | |
tree | a18a706dffa5baf86a3b12bbfb4f81caa097f349 /lib/libc/sys/getpriority.2 | |
parent | 2a27bd86e6002c871e3b5561a5334653bb222a77 (diff) | |
download | FreeBSD-src-be22b15ae2ff8d7fe06b6e14fddf0c5b444a95da.zip FreeBSD-src-be22b15ae2ff8d7fe06b6e14fddf0c5b444a95da.tar.gz |
BSD 4.4 Lite Lib Sources
Diffstat (limited to 'lib/libc/sys/getpriority.2')
-rw-r--r-- | lib/libc/sys/getpriority.2 | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/lib/libc/sys/getpriority.2 b/lib/libc/sys/getpriority.2 new file mode 100644 index 0000000..aa151a0 --- /dev/null +++ b/lib/libc/sys/getpriority.2 @@ -0,0 +1,142 @@ +.\" Copyright (c) 1980, 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)getpriority.2 8.1 (Berkeley) 6/4/93 +.\" +.Dd June 4, 1993 +.Dt GETPRIORITY 2 +.Os BSD 4 +.Sh NAME +.Nm getpriority , +.Nm setpriority +.Nd get/set program scheduling priority +.Sh SYNOPSIS +.Fd #include <sys/time.h> +.Fd #include <sys/resource.h> +.Ft int +.Fn getpriority "int which" "int who" +.Ft int +.Fn setpriority "int which" "int who" "int prio" +.Sh DESCRIPTION +The scheduling +priority of the process, process group, or user, as indicated by +.Fa which +and +.Fa who +is obtained with the +.Fn getpriority +call and set with the +.Fn setpriority +call. +.Fa Which +is one of +.Dv PRIO_PROCESS , +.Dv PRIO_PGRP , +or +.Dv PRIO_USER , +and +.Fa who +is interpreted relative to +.Fa which +(a process identifier for +.Dv PRIO_PROCESS , +process group +identifier for +.Dv PRIO_PGRP , +and a user ID for +.Dv PRIO_USER ) . +A zero value of +.Fa who +denotes the current process, process group, or user. +.Fa Prio +is a value in the range -20 to 20. The default priority is 0; +lower priorities cause more favorable scheduling. +.Pp +The +.Fn getpriority +call returns the highest priority (lowest numerical value) +enjoyed by any of the specified processes. The +.Fn setpriority +call sets the priorities of all of the specified processes +to the specified value. Only the super-user may lower priorities. +.Sh RETURN VALUES +Since +.Fn getpriority +can legitimately return the value -1, it is necessary +to clear the external variable +.Va errno +prior to the +call, then check it afterward to determine +if a -1 is an error or a legitimate value. +The +.Fn setpriority +call returns 0 if there is no error, or +-1 if there is. +.Sh ERRORS +.Fn Getpriority +and +.Fn setpriority +will fail if: +.Bl -tag -width Er +.It Bq Er ESRCH +No process was located using the +.Fa which +and +.Fa who +values specified. +.It Bq Er EINVAL +.Fa Which +was not one of +.Dv PRIO_PROCESS , +.Dv PRIO_PGRP , +or +.Dv PRIO_USER . +.El +.Pp +.Bl -tag -width Er +In addition to the errors indicated above, +.Fn setpriority +will fail if: +.It Bq Er EPERM +A process was located, but neither its effective nor real user +ID matched the effective user ID of the caller. +.It Bq Er EACCES +A non super-user attempted to lower a process priority. +.El +.Sh SEE ALSO +.Xr nice 1 , +.Xr fork 2 , +.Xr renice 8 +.Sh HISTORY +The +.Nm +function call appeared in +.Bx 4.2 . |