In some cases, you may want to know the number of processes working in the system. You can know it by grep -ef | grep <process name> | wc -l

Following is the example to check the total number of process for "postgres":

ps -ef | grep postgres | wc -l


Following is the example to check the total number of process for "ffmpeg":

ps -ef | grep ffmpeg | wc -l

If you want to check the processes with full path,

ps -aux | grep bot 

Then, you will see:

root     17364  0.0  0.0 436760 19536 ?        S    09:00   0:00 php /pub/production/_bot/bot_main.php
root     17402  0.0  0.0 113284  1596 ?        Ss   09:00   0:00 bash -c cd "/lib/production/_bot" && php import_db.php
root     17933  0.0  0.0 436760 19532 ?        S    09:05   0:00 php /pub/production/_bot/bot_main.php
root     18038  0.0  0.0 113284  1596 ?        Ss   09:05   0:00 bash -c cd "/lib/production/_bot" && php channels.php
kurapa   21211  0.0  0.0 112816   972 pts/2    S+   09:28   0:00 grep --color=auto bot

To count its list,

ps -aux | grep bot | wc -l