#!/usr/bin/pagsh.openafs
# -*- Shell-Script -*-
#
# Usage:
#
#    run-in-pagsh [--fg] name command [argument ...]
#
# The argument `name' is a short description of the program to call,
# without any spaces.  It is used for making a PID file, which ensures
# that only one instance of your command is running.
#
# The arguments that come afterward specify the command to run and its
# arguments, if any.
#
# If the command will run in the foreground, then you should use the
# `--fg' argument, making sure that it is the very first argument to
# run-in-pagsh.
#
# Examples:
#
#    run-in-pagsh interchange ~/interchange/bin/interchange
#
#    run-in-pagsh --fg clean-mail ~/scripts/clean-mail
#
# Make sure that the ~/.run directory exists and is writable.
# See http://wiki2.hcoop.net/MemberManual/RunningUnattendedCommands
# for instructions on how to accomplish this.

# Allow user to specify "--fg" argument.
if test "$1" = "--fg"; then
    shift
    BGFLAG=
else
    BGFLAG=-b
fi

# Sanity checks.
if test -z "$2"; then
    echo "Error: not enough arguments."
    echo "Usage: run-in-pagsh name [--fg] command [argument ...]"
    exit 1
elif test ! -d "$HOME/.run"; then
    echo "Error: the ~/.run directory must exist before running this script."
    exit 1
fi

# Use a different PID file for each program.
K5PID=$HOME/.run/$1.pid

# The command to run.
shift
CMD="$*"

# Try to deduce the user we're running as.
if test -z "$USER"; then
    if test -n "$LOGNAME"; then
        USER=$LOGNAME
    elif test -n "$HOME"; then
        USER=$(basename "$HOME")
    else
        echo "Error: cannot deduce your username"
        exit 1
    fi
fi

# Your keytab file.
KTAB=/etc/keytabs/user.daemon/$USER

# Terminate current k5start process, if one is running.
if test -f "$K5PID"; then
    kill `cat -- "$K5PID"` 2>/dev/null
    /usr/bin/k5start -qtU -f "$KTAB" -- rm -f "$K5PID"
fi

if test -n "$BGFLAG"; then

    # Start fresh k5start daemon which will be refreshing tickets
    # every 540 min.
    /usr/bin/k5start -U -b -K 540 -t -p "$K5PID" -f "$KTAB"

    # Run actual service with arguments as provided on command line.
    $CMD

else

    # Run the command once, in the foreground, cleaning up its PID
    # file when done.
    /usr/bin/k5start -U -K 540 -t -p "$K5PID" -f "$KTAB" -- $CMD
    /usr/bin/k5start -qtU -f "$KTAB" -- rm -f "$K5PID"
fi