# -*-Shell-script-*-
#
# Common functions for PLC startup/shutdown scripts
#
# Mark Huang <mlhuang@cs.princeton.edu>
# Copyright (C) 2006 The Trustees of Princeton University
#
# $Id$
#

export PATH=/sbin:/bin:/usr/bin:/usr/sbin

# Source function library
. /etc/init.d/functions

# Total number of errors
ERRORS=0

# Count the exit status of the last command
check ()
{
    ERRORS=$(($ERRORS+$?))
}

# Print status header
dialog ()
{
    echo -n "PLC: $*: " >&3
}

# Print result
result ()
{
    if [ $ERRORS -eq 0 ] ; then
	success "$*" >&3
    else
	failure "$*" >&3
    fi
    echo >&3
}

# Start up a program with a plc_ prefix
plc_daemon ()
{
    base=${1##*/}

    # See if it's already running. Look *only* at the pid file.
    if [ -f /var/run/plc_${base}.pid ]; then
	local line p
	read line < /var/run/plc_${base}.pid
	for p in $line ; do
		[ -z "${p//[0-9]/}" -a -d "/proc/$p" ] && pid="$pid $p"
	done
    fi

    [ -n "${pid:-}" -a -z "${force:-}" ] && return

    # And start it up.
    # Thierry -- June 18 2007
    # when invoking, e.g. service plc start httpd from an ssh connection
    # ssh stupidly hangs when everything is done
    # it turns out the forked ssh daemon exhibits the following stack at that point
    # (gdb) where
    # #0  0x001d6402 in __kernel_vsyscall ()
    # #1  0x003c2e7d in ___newselect_nocancel () from /lib/libc.so.6
    # #2  0x004387b4 in main () from /usr/sbin/sshd
    # So I figured the various file descriptors used were not properly closed
    (exec 3>&- 4>&- ; exec -a plc_${base} $*)
    ret=$?

    if [ -f /var/run/${base}.pid ] ; then
	mv /var/run/${base}.pid /var/run/plc_${base}.pid
    fi

    return $ret
}

# Print IP address of hostname if resolvable
gethostbyname ()
{
    python -c 'import socket; import sys; print socket.gethostbyname(sys.argv[1])' $1 2>/dev/null
}

# Forcefully make a symlink
symlink ()
{
    mkdir -p $(dirname $2)
    rm -f $2
    ln -s $1 $2
}

# Argument(s) or stdin to lowercase stdout
lower ()
{
    if [ ${#*} -ge 1 ] ; then
	tr A-Z a-z <<<$*
    else
	tr A-Z a-z
    fi
}

# Argument(s) or stdin to uppercase stdout
upper ()
{
    if [ ${#*} -ge 1 ] ; then
	tr a-z A-Z <<<$*
    else
	tr a-z A-Z
    fi
}

# Make copies of stdout and stderr. The plc initscript redirects
# stdout and stderr to a logfile if -v is not specified.
[ ! -e /proc/self/fd/3 ] && exec 3>&1
[ ! -e /proc/self/fd/4 ] && exec 4>&2