when you put a path name to a function file immediately after the #!/bin/sh, what does it mean? it looks like this
#!/bin/sh /etc/rc.common

Thanks in advance! anyway, this is my first post!

this is the full text.

#!/bin/sh /etc/rc.common
# Copyright (C) 2008-2011 OpenWrt.org

START=60

smb_header() {
local interface
config_get interface $1 interface "loopback lan"

# resolve interfaces
local interfaces=$(
include /lib/network
scan_interfaces

local net
for net in $interface; do
local ifname
config_get ifname "$net" ifname
[ -n "$ifname" ] && {
local ipaddr netmask
config_get ipaddr "$net" ipaddr
config_get netmask "$net" netmask
[ -n "$ipaddr" ] && echo -n "$ipaddr/${netmask:-255.255.255.255} "

local ip6addr
config_get ip6addr "$net" ip6addr
[ -n "$ip6addr" ] && echo -n "$ip6addr "
}

echo -n "${ifname:-$net} "
done
)

local name workgroup description charset
local hostname="$(uci_get system.@system[0].hostname)"

config_get name $1 name "${hostname:-OpenWrt}"
config_get workgroup $1 workgroup "${hostname:-OpenWrt}"
config_get description $1 description "Samba on ${hostname:-OpenWrt}"
config_get charset $1 charset "UTF-8"

mkdir -p /var/etc
sed -e "s#|NAME|#$name#g" \
-e "s#|WORKGROUP|#$workgroup#g" \
-e "s#|DESCRIPTION|#$description#g" \
-e "s#|INTERFACES|#$interfaces#g" \
-e "s#|CHARSET|#$charset#g" \
/etc/samba/smb.conf.template > /var/etc/smb.conf

local homes
config_get_bool homes $1 homes 0
[ $homes -gt 0 ] && {
cat <<EOT >> /var/etc/smb.conf

[homes]
comment = Home Directories
browsable = no
read only = no
create mode = 0750
EOT
}

[ -L /etc/samba/smb.conf ] || ln -nsf /var/etc/smb.conf /etc/samba/smb.conf
}

smb_add_share() {
local name
local path
local users
local read_only
local guest_ok
local create_mask
local dir_mask

config_get name $1 name
config_get path $1 path
config_get users $1 users
config_get read_only $1 read_only
config_get guest_ok $1 guest_ok
config_get create_mask $1 create_mask
config_get dir_mask $1 dir_mask

[ -z "$name" -o -z "$path" ] && return

echo -e "\n[$name]\n\tpath = $path" >> /var/etc/smb.conf
[ -n "$users" ] && echo -e "\tvalid users = $users" >> /var/etc/smb.conf
[ -n "$read_only" ] && echo -e "\tread only = $read_only" >> /var/etc/smb.conf
[ -n "$guest_ok" ] && echo -e "\tguest ok = $guest_ok" >> /var/etc/smb.conf
[ -n "$create_mask" ] && echo -e "\tcreate mask = $create_mask" >> /var/etc/smb.conf
[ -n "$dir_mask" ] && echo -e "\tdirectory mask = $dir_mask" >> /var/etc/smb.conf
}

start() {
config_load samba
config_foreach smb_header samba
config_foreach smb_add_share sambashare
service_start /usr/sbin/smbd -D
service_start /usr/sbin/nmbd -D
}

stop() {
service_stop /usr/sbin/smbd
service_stop /usr/sbin/nmbd
}

Perhaps the second entry is an argument to "sh"--telling it where to find a key file.

thanks for replying! on closer look, i find the path name of this script seems to be used as a positional parameter to /etc/rc.common

cat /etc/rc.common
#!/bin/sh
# Copyright (C) 2006-2011 OpenWrt.org

. $IPKG_INSTROOT/lib/functions.sh
. $IPKG_INSTROOT/lib/functions/service.sh

initscript=$1
action=${2:-help}
shift 2

start() {
return 0
}

stop() {
return 0
}

reload() {
return 1
}

restart() {
trap '' TERM
stop "$@"
start "$@"
}

boot() {
start "$@"
}

shutdown() {
stop
}

disable() {
name="$(basename "${initscript}")"
rm -f "$IPKG_INSTROOT"/etc/rc.d/S??$name
rm -f "$IPKG_INSTROOT"/etc/rc.d/K??$name
}

enable() {
name="$(basename "${initscript}")"
disable
[ -n "$START" -o -n "$STOP" ] || {
echo "/etc/init.d/$name does not have a START or STOP value"
return 1
}
[ "$START" ] && ln -s "../init.d/$name" "$IPKG_INSTROOT/etc/rc.d/S${START}${name##S[0-9][0-9]}"
[ "$STOP" ] && ln -s "../init.d/$name" "$IPKG_INSTROOT/etc/rc.d/K${STOP}${name##K[0-9][0-9]}"
}

enabled() {
name="$(basename "${initscript}")"
[ -x "$IPKG_INSTROOT/etc/rc.d/S${START}${name##S[0-9][0-9]}" ]
}

depends() {
return 0
}

help() {
cat <<EOF
Syntax: $initscript [command]

Available commands:
start Start the service
stop Stop the service
restart Restart the service
reload Reload configuration files (or restart if that fails)
enable Enable service autostart
disable Disable service autostart
$EXTRA_HELP
EOF
}

. "$initscript"

ALL_COMMANDS="start stop reload restart boot shutdown enable disable enabled depends ${EXTRA_COMMANDS}"
list_contains ALL_COMMANDS "$action" || action=help
[ "$action" = "reload" ] && action='eval reload "$@" || restart "$@" && :'
$action "$@"