Shell script get the right PID - linux

Question

I wrote a little program that I want to start as a service on Opensuse 11.3
This is from the init.d script, it starts my processes as I want but I don't get the right PID.
What am I missing?
echo "Starting DHCPALERT"
for (( i = 1; i <= $DHCP_AL_DAEMONS; i++ ))
do
var="DHCP_AL_$i"
START_CMD="exec /sbin/startproc -p "$DHCP_AL_PID_DIR"p_"$i".pid -l "$DHCP_AL_LOG_DIR"log_"$i".log "$DHCPALERT_BIN" "${!var}" &"
eval $START_CMD
echo "PID: "$!
echo "Command: "$START_CMD
done
results in
PID: 47347
Command: (/sbin/startproc -p /var/log/sthserver/dhcpalert/p_2.pid -l /var/log/sthserver/dhcpalert/log_2.log /usr/sbin/dhcpalert -i eth1 -c ./test.sh -a 00:15:5D:0A:16:07 -v )&
but pidof returns some othe pid.
If I try to execute it directly:
exec /sbin/startproc -p "$DHCP_AL_PID_DIR"p_"$i".pid -l "$DHCP_AL_LOG_DIR"log_"$i".log "$DHCPALERT_BIN" "${!var}" &
Then I get errors:
startproc: exit status of parent of /usr/sbin/dhcpalert: 1
I suppose because I don't escape the variables the right way?
This is the whole script:
#!/bin/sh
# Check for missing binaries (stale symlinks should not happen)
# Note: Special treatment of stop for LSB conformance
DHCPALERT_BIN=/usr/sbin/dhcpalert
#-x FILE exists and is executable
test -x $DHCPALERT_BIN || { echo "$DHCPALERT_BIN not installed";
if [ "$1" = "stop" ]; then exit 0;
else exit 5; fi; }
# Check for existence of needed config file and read it
DHCPALERT_CONFIG=/etc/sysconfig/dhcpalert
#-r FILE exists and is readable
test -r $DHCPALERT_CONFIG || { echo "$DHCPALERT_CONFIG not existing";
if [ "$1" = "stop" ]; then exit 0;
else exit 6; fi; }
# Read config to system VARs for this shell session only same as "source FILE"
. $DHCPALERT_CONFIG
#check for exitstence of the log dir
if [ -d "$DHCP_AL_LOG_DIR" ]; then
echo "exists 1"
echo "exists 2"
echo "exists 3"
if [ "$1" = "start" ]; then
echo "Deleting all old log files from: "
echo "Dir:... "$DHCP_AL_LOG_DIR
rm -R $DHCP_AL_LOG_DIR
mkdir $DHCP_AL_LOG_DIR
fi
else
echo "does not exist 1"
echo "does not exist 2"
echo "does not exist 3"
echo "Directory for Logfiles does not exist."
echo "Dir:... "$DHCP_AL_LOG_DIR
echo "Createing dir..."
mkdir $DHCP_AL_LOG_DIR
fi
. /etc/rc.status
# Reset status of this service
rc_reset
case "$1" in
start)
echo "Starting DHCPALERT"
for (( i = 1; i <= $DHCP_AL_DAEMONS; i++ ))
do
var="DHCP_AL_$i"
exec /sbin/startproc -p "$DHCP_AL_PID_DIR"p_"$i".pid -l "$DHCP_AL_LOG_DIR"log_"$i".log "$DHCPALERT_BIN" "${!var}" &
# START_CMD="exec /sbin/startproc -p "$DHCP_AL_PID_DIR"p_"$i".pid -l "$DHCP_AL_LOG_DIR"log_"$i".log "$DHCPALERT_BIN" "${!var}" &"
# eval $START_CMD
echo "PID: "$!
# echo "Command: "$START_CMD
done
rc_status -v
;;
stop)
echo -n "Shutting down DHCPALERT "
/sbin/killproc -TERM $DHCPALERT_BIN
rc_status -v
;;
try-restart|condrestart)
if test "$1" = "condrestart"; then
echo "${attn} Use try-restart ${done}(LSB)${attn} rather than condrestart ${warn}(RH)${norm}"
fi
$0 status
if test $? = 0; then
$0 restart
else
rc_reset # Not running is not a failure.
fi
rc_status
;;
restart)
$0 stop
$0 start
rc_status
;;
force-reload)
echo -n "Reload service DHCPALERT "
/sbin/killproc -HUP $DHCPALERT_BIN
rc_status -v
;;
reload)
echo -n "Reload service DHCPALERT "
/sbin/killproc -HUP $DHCPALERT_BIN
rc_status -v
;;
status)
echo -n "Checking for service DHCPALERT "
/sbin/checkproc $DHCPALERT_BIN
rc_status -v
;;
probe)
test /etc/DHCPALERT/DHCPALERT.conf -nt /var/run/DHCPALERT.pid && echo reload
;;
*)
echo "Usage: $0 {start|stop|status|try-restart|restart|force-reload|reload|probe}"
exit 1
;;
esac
rc_exit
The configfile:
## Specifiy where to store the Pid files
DHCP_AL_PID_DIR="/var/log/sthserver/dhcpalert/"
##
## Specifiy where to store the Log file
DHCP_AL_LOG_DIR="/var/log/sthserver/dhcpalert/"
##
## is needed to determine how many vars should be read and started!
DHCP_AL_DAEMONS="2"
##
## Then DHCP_AL_<number> to specify the command that one instance of
## dhcpalert should be started
DHCP_AL_1="-i eth0 -c ./test.sh -a 00:15:5D:0A:16:06 -v"
DHCP_AL_2="-i eth1 -c ./test.sh -a 00:15:5D:0A:16:07 -v"

Answer 1

Add exec to it to prevent forking:
START_CMD="(exec /sbin/startproc -p "$DHCP_AL_PID_DIR"p_"$i".pid -l "$DHCP_AL_LOG_DIR"log_"$i".log "$DHCPALERT_BIN" "${!var}") &"
Update. Please try this script:
#!/bin/bash
# Check for missing binaries (stale symlinks should not happen)
# Note: Special treatment of stop for LSB conformance
DHCPALERT_BIN=/usr/sbin/dhcpalert
#-x FILE exists and is executable
[[ -x $DHCPALERT_BIN ]] || {
echo "$DHCPALERT_BIN not installed"
if [ "$1" = "stop" ]; then
exit 0
else
exit 5
fi
}
# Check for existence of needed config file and read it
DHCPALERT_CONFIG=/etc/sysconfig/dhcpalert
#-r FILE exists and is readable
[[ -r $DHCPALERT_CONFIG ]] || {
echo "$DHCPALERT_CONFIG not existing"
if [[ $1 == stop ]]; then
exit 0
else
exit 6
fi
}
# Read config to system VARs for this shell session only same as "source FILE"
. "$DHCPALERT_CONFIG"
#check for exitstence of the log dir
CREATE_DIR=false
if [[ -d $DHCP_AL_LOG_DIR ]]; then
echo "exists 1"
echo "exists 2"
echo "exists 3"
if [[ $1 == start ]]; then
echo "Deleting all old log files from: "
echo "Dir:... $DHCP_AL_LOG_DIR"
rm -R "$DHCP_AL_LOG_DIR"
CREATE_DIR=true
fi
else
echo "does not exist 1"
echo "does not exist 2"
echo "does not exist 3"
echo "Directory for Logfiles does not exist."
CREATE_DIR=true
fi
if [[ $CREATE_DIR == true ]]; then
echo "Dir:... $DHCP_AL_LOG_DIR"
echo "Createing dir..."
mkdir "$DHCP_AL_LOG_DIR" || {
echo "Failed to create directory $DHCP_AL_LOG_DIR"
exit 1
}
fi
. /etc/rc.status
# Reset status of this service
rc_reset
case "$1" in
start)
echo "Starting DHCPALERT"
for (( I = 1; I <= DHCP_AL_DAEMONS; ++I )); do
REF="DHCP_AL_${I}[#]"
COMMAND=(/sbin/startproc -p "${DHCP_AL_PID_DIR}p_${I}.pid" -l "${DHCP_AL_LOG_DIR}log_${I}.log" "$DHCPALERT_BIN" "${!REF}")
echo "COMMAND: ${COMMAND[*]}"
"${COMMAND[#]}" &
PID=$!
echo "PID: $PID"
done
rc_status -v
;;
stop)
echo -n "Shutting down DHCPALERT "
/sbin/killproc -TERM "$DHCPALERT_BIN"
rc_status -v
;;
try-restart|condrestart)
[[ $1 == condrestart ]] && echo "${attn} Use try-restart ${done}(LSB)${attn} rather than condrestart ${warn}(RH)${norm}"
"$0" status ## ??
if [[ $? -eq 0 ]]; then
"$0" restart
else
rc_reset # Not running is not a failure.
fi
rc_status
;;
restart)
"$0" stop
"$0" start
rc_status
;;
force-reload)
echo -n "Reload service DHCPALERT "
/sbin/killproc -HUP "$DHCPALERT_BIN"
rc_status -v
;;
reload)
echo -n "Reload service DHCPALERT "
/sbin/killproc -HUP "$DHCPALERT_BIN"
rc_status -v
;;
status)
echo -n "Checking for service DHCPALERT "
/sbin/checkproc "$DHCPALERT_BIN"
rc_status -v
;;
probe)
[[ /etc/DHCPALERT/DHCPALERT.conf -nt /var/run/DHCPALERT.pid ]] & echo reload
;;
*)
echo "Usage: $0 {start|stop|status|try-restart|restart|force-reload|reload|probe}"
exit 1
;;
esac
rc_exit
Config file:
## Specifiy where to store the Pid files
DHCP_AL_PID_DIR="/var/log/sthserver/dhcpalert/"
##
## Specifiy where to store the Log file
DHCP_AL_LOG_DIR="/var/log/sthserver/dhcpalert/"
##
## is needed to determine how many vars should be read and started!
DHCP_AL_DAEMONS="2"
##
## Then DHCP_AL_<number> to specify the command that one instance of
## dhcpalert should be started
DHCP_AL_1=(-i eth0 -c ./test.sh -a 00:15:5D:0A:16:06 -v)
DHCP_AL_2=(-i eth1 -c ./test.sh -a 00:15:5D:0A:16:07 -v)

Answer 2

When you have a shell-command inside parentheses you start a new sub-shell. You run this sub-shell in the background and it's that sub-shells process id you get with $!.
There are two solutions: The first is to not run the /sbin/startproc command in a subshell, but directly and put that in the background. The secomd solution is to monitor the pid file created by /sbin/startproc.