Ubuntu-fr

#! /usr/bin/env bash

######################################################################

## Program usage
usage() {
    cat <<EOF
NAME
    supernice - execute a program with the lowest available priority
    superstrong - execute a program with the highest available priority

SYNOPSIS
    $prog COMMAND ...
    $prog PID ...

DESCRIPTION
    supernice will execute a program with the lowest available priority.
    superstrong will execute a program with the highest available priority.

    It can start a new command or alter running processes, if given
    their pids.

AUTHOR
    Yannick Le Saint (kyncani) <y.lesaint@gmail.com>

VERSION
    $version
EOF
}

######################################################################

## Give a message if some binary is missing, like which package to
## install. Only give a warning once per tool.
missing_tool() {
    local t
    local p
    for t in "$@"; do
        echo " $SUPERNICE_WARN_MISSING " | grep -q " $t " && continue
        if type apt-file &>/dev/null; then
            p=`
                apt-file search "bin/$t" \
                | grep "bin/$t\$" \
                | sed "s/:.*//" \
                | sort \
                | uniq \
                | tr '\n' ':' \
                | sed 's/:::*/:/g; s/^://; s/:$//; s/:/ or /g' \
                `
        else
            p=
        fi
        if test "$p" = ""; then
            echo "$prog: $t is missing." >&2
        else
            echo "$prog: $t is missing, you may need to install $p." >&2
        fi
        if test "$SUPERNICE_WARN_MISSING" = ""; then
            export SUPERNICE_WARN_MISSING=" $t "
        else
            export SUPERNICE_WARN_MISSING="$SUPERNICE_WARN_MISSING$t "
        fi
    done
}

## Supernice a running process, given its pid
supernice_this() {
    local ret=true
    local foundtool=false
    if ! echo "$1" | grep -q '^[[:digit:]][[:digit:]]*$'; then
        echo "$prog: not a pid: $1" >&2
        return 1
    fi
    if type renice &>/dev/null; then
        foundtool=true
        if $supernicemode; then
            renice 20 "$1" >/dev/null
        else
            renice -20 "$1" >/dev/null
        fi || ret=false
    else
        missing_tool renice
    fi
    if type ionice &>/dev/null; then
        foundtool=true
        if $supernicemode; then
            ionice -c3 -p"$1"
        else
            ionice -c1 -p"$1"
        fi || ret=false
    else
        missing_tool ionice
    fi
    if type schedtool &>/dev/null; then
        foundtool=true
        if $supernicemode; then
            schedtool -D "$1"
        else
            schedtool -F -p 20 "$1"
        fi || ret=false
    else
        missing_tool schedtool
    fi
    if ! $foundtool; then
        echo "$prog: cannot find neither renice, schedtool nor ionice." >&1
        ret=false
    fi
    $ret
}

######################################################################

## Program name
prog=`basename "$0"`

## Program version
version="1.0.3"

## Supernice mode, false means we're in superstrong mode
supernicemode=

######################################################################

if test $# -lt 1; then
    usage >&2
    exit 1
fi

if test "$1" = "-h" || test "$1" = "--help"; then
    usage && exit || exit 1
fi

case "$prog" in
    supernice) supernicemode=true;;
    superstrong) supernicemode=false;;
    *)
        echo "$prog: should be named supernice or superstrong." >&2
        supernicemode=
        ;;
esac

if echo "$1" | grep -q '^[[:digit:]][[:digit:]]*$'; then
    test "$supernicemode" = "" && exit 1
    ret=true
    for pid in "$@"; do
        supernice_this "$pid" || ret=false
    done
    $ret
else
    test "$supernicemode" = "" || supernice_this $$
    exec "$@"
fi

######################################################################
##
## CHANGELOG
##
## - 02/02/2009,21:59 (version 1.0.3)
##   - Added superstrong mode.
## - 31/01/2009,21:10 (version 1.0.2)
##   - Debian: Nicely tell which packages to install using apt-file.
##   - Change cpu priority before io priority.
## - 26/01/2009,21:28 (version 1.0.1)
##   - Added --help option.
##   - Can now supernice running processes.
##   - Added some documentation.
##   - Added some error message in case no basic tools are found.
## - 26/01/2009,21:11 (version 1.0.0)
##   - Added version and changelog.
##
######################################################################