pwtk.tcl

::pwtk::nice

::pwtk::nice

SYNOPSIS

proc ::pwtk::nice {args} {

PURPOSE

Set or query the niceness value for the execution of programs (aka "nice"). Here is an example of how the program is run in the terminal with the highest niceness (aka nice -19):

    
     nice -19 program.x

or for parallel execution:

     nice -19 mpirun -n 8 program.x

The effect of this command is that, for example, with the "::pwtk::nice -19" call, all subsequent calculations will be run with nice -19.

USAGE

   Set mode:
     ::pwtk::nice value

   Query mode:    
     ::pwtk::nice

ARGUMENTS

value -- value of the niceness; irrespective of whether negative or positive value is supplied, its magnitude is used and the 'nice' is run as: nice -[expr abs($value)]

RETURN VALUE

The current (absolute) value of the niceness or an empty string if niceness was not set.

SOURCE

    variable RUNopt

    if { [llength $args] == 0 } {
        return [expr { [info exists RUNopt(NICE)] ? $RUNopt(NICE) : {} }]
    } elseif { [llength $args] == 1 } {
        set args [lindex $args 0]
        if { $args != {} } {
            if { ! [string is integer $args] } {
                ::pwtk::error  "expecting an integer but got: $args" 1
            }
            set RUNopt(NICE) [expr abs($args)]
            set RUNopt(NICE_CMD) "nice -$RUNopt(NICE)"
        } else {
            set RUNopt(NICE) {}
            set RUNopt(NICE_CMD) {}
        }
    } else {
        ::pwtk::error "expecting zero or one argument, but got: $args" 1
    }
    return $RUNopt(NICE)
}

TABLE OF CONTENTS

::pwtk::nice