'ensure' -- process assurance for the rest of us

#!/usr/bin/env zsh
#
# ensure -- a simple process starter
#
# Usage: ensure  [arg1, ...]
#
# For example:
#               $ ensure urxvtd -q -f -o
#               -- Ran 'urxvtd -q -f -o'
#               $ ensure urxvtd -q -f -o
#               -- Already running
#
#       But we don't care about arguments, so a further
#               $ ensure urxvtd -q
#               -- Already running
#
# This script is most useful for running daemons like:
#       urxvtd, mpd, synergys, ... and I use it for this purpose
#       in my .xsession/.xinitrc file.

cmd="${1}"

if [[ -z "${cmd}" ]]; then
        echo "Usage: $(basename $0) "
        return 1
else
        if [[ -x $(which pidof) ]]; then
                pidof "${cmd}" > /dev/null && \
                                echo "-- Already running" || \
                                ( $(${*} >/dev/null 2>&1 &) && echo "-- Ran '${*}'" )
        else
                ps xc | tail +2 | awk '{print $5}' | grep "${cmd}" > /dev/null && \
                                echo "-- Already running" || \
                                ( $(${*} >/dev/null 2>&1 &) && echo "-- Ran '${*}'" )
        fi
fi

# vim:et:ts=2:sts=2:sw=2:

P.S.
Untested: this should work in most decent shells (bash, zsh, ksh)