nice

- invoke a command with an altered scheduling priority

Synopsis

/usr/bin/nice [-increment | -n increment] command 
     [argument]...

/usr/xpg4/bin/nice [-increment | -n increment] command 
     [argument]...

csh Builtin

nice [-increment | +increment] [command]

Description

The nice utility invokes command, requesting that it be run with a different system scheduling priority. The priocntl(1) command is a more general interface to scheduler functions.

The invoking process (generally the user's shell) must be in a scheduling class that supports nice.

If the C shell (see csh(1)) is used, the full path of the command must be specified. Otherwise, the csh built-in version of nice will be invoked. See csh Builtin below.

/usr/bin/nice

If nice executes commands with arguments, it uses the default shell /usr/bin/sh (see sh(1)).

/usr/xpg4/bin/nice

If nice executes commands with arguments, it uses /usr/xpg4/bin/sh (see ksh(1)).

csh Builtin

nice is also a csh built-in command with behavior different from the utility versions. See csh(1) for description.

Options

The following options are supported:

-increment | -n increment

increment is a positive or negative decimal integer that has the same effect on the execution of the utility as if the utility had called the nice() function with the numeric value of the increment option-argument. See nice(2). nice() errors, other than EINVAL, are ignored. If not specified, an increment of 10 is assumed.

The super-user may run commands with priority higher than normal by using a negative increment such as –10. A negative increment assigned by an unprivileged user is ignored.

Operands

The following operands are supported:

command

The name of a command that is to be invoked. If command names any of the special built-in utilities (see shell_builtins(1)), the results are undefined.

argument

Any string to be supplied as an argument when invoking command.

Environment Variables

See environ(5) for descriptions of the following environment variables that affect the execution of nice: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES, PATH, and NLSPATH.

Exit Status

If command is invoked, the exit status of nice will be the exit status of command. Otherwise, nice will exit with one of the following values:

1-125

An error occurred.

126

command was found but could not be invoked.

127

command could not be found.

Attributes

See attributes(5) for descriptions of the following attributes:

/usr/bin/nice

/usr/xpg4/bin/nice

See Also

csh(1), ksh(1), nohup(1), priocntl(1), sh(1), shell_builtins(1), nice(2), attributes(5), environ(5), standards(5)