Like a Multi thread in Linux shell script

Multi thread in shell script code

your initial code

your loop

{

    {

        do something

    }&

}

end loop

wait

SQLite db lock

sqlite3 -cmd ".timeout 1000" data_base "SQL string"

Example

#!/bin/sh

cd /www/pages/system/

ConfigPath="/www/pages/_config/"

LOGFILE="${ConfigPath}test.log"

echo ${ConfigPath}

echo ${LOGFILE}

##  Get camera list from database

array=($(sqlite3 -cmd ".timeout 1000" ../bootstrap/db_camera "SELECT active, status, record, id, address, camera_port, camera_login_id, camera_login_pw, camera_protocol, camera_link FROM db_camera WHERE active=1;"))

for i in "${array[@]}"; do

    {

        echo ""

        echo "*** START"

    

        ##  Get camera information

        c_active=$(echo $i |awk -F '|' '{printf "%s" , $1}')

        echo "Data: $i"

        if [ $c_active == 1 ];then

            c_status=$(echo $i |awk -F '|' '{printf "%s" , $2}')

            c_record=$(echo $i |awk -F '|' '{printf "%s" , $3}')

            c_id=$(echo $i |awk -F '|' '{printf "%s" , $4}')

            c_address=$(echo $i |awk -F '|' '{printf "%s" , $5}')

            c_ip=$(traceroute ${c_address} |head -1 |cut -d '(' -f 2 |cut -d ')' -f 1)

            c_port=$(echo $i |awk -F '|' '{printf "%s" , $6}')

            c_login_id=$(echo $i |awk -F '|' '{printf "%s" , $7}')

            c_login_pw=$(echo $i |awk -F '|' '{printf "%s" , $8}')

            c_protocol=$(echo $i |awk -F '|' '{printf "%s" , $9}')

            c_link=$(echo $i |awk -F '|' '{printf "%s" , $10}')

        

            ##  Get the status of camera and update to database

            camera_live=$(timeout --preserve-status 10s echo >/dev/tcp/${c_address}/${c_port} && echo '1' || echo '0')

            sqlite3 -cmd ".timeout 1000" ../bootstrap/db_camera "UPDATE db_camera SET status=${camera_live} WHERE id=${c_id};"

            echo "Update db: status = $camera_live"

            

            ##  Start record process if exists and not in record process

            if [ $camera_live == 1 ];then

                if [ $c_record == 1 ];then

                    if [ $c_protocol == "rtsp" ];then

                        echo "Start record process"

                        

                        sqlite3 -cmd ".timeout 1000" ../bootstrap/db_camera "UPDATE db_camera SET record=2 WHERE id=${c_id};"

                        echo "Update db: record = 2"

                        

                        echo "Get video link"

                        if [ ${#c_login_id} -ne 0 ];then

                            camera_login_link="${c_protocol}://${c_login_id}:${c_login_pw}@${c_ip}:${c_port}/${c_link}"

                        else

                            camera_login_link="${c_protocol}://${c_ip}:${c_port}/${c_link}"

                        fi

                        echo $camera_login_link

                        /www/pages/raid/ffmpeg -rtsp_transport tcp -i "${camera_login_link}" -c copy -f segment -segment_time 180 -reset_timestamps 1  -strftime 1 /www/pages/raid/Record/camera_${c_id}_%Y%m%d_%H%M%S.mp4 -y &

                    fi

                fi

                

                if [ $c_record == 3 ];then

                    echo "Stop record process"

                    pkill -2 -f "camera_${c_id}"

                    sqlite3 -cmd ".timeout 1000" ../bootstrap/db_camera "UPDATE db_camera SET record=0 WHERE id=${c_id};"

                    echo "Update db: record = 0"

                fi

            fi

        fi

        echo "*** END"

        echo ""

    }&

done 

wait