I was looking for the best way to find the number of running processes with the same name via the command line in Linux. For example if I wanted to find the number of bash processes running and get "5". Currently I have a script that does a 'pidof ' and then does a count on the tokenized string. This works fine but I was wondering if there was a better way that can be done entirely via the command line. Thanks in advance for your help.
On systems that have pgrep available, the -c option returns a count of the number of processes that match the given name
pgrep -c command_name
Note that this is a grep-style match, not an exact match, so e.g. pgrep sh will also match bash processes. If you want an exact match, also use the -x option.
If pgrep is not available, you can use ps and wc.
ps -C command_name --no-headers | wc -l
The -C option to ps takes command_name as an argument, and the program prints a table of information about processes whose executable name matches the given command name. This is an exact match, not grep-style. The --no-headers option suppresses the headers of the table, which are normally printed as the first line. With --no-headers, you get one line per process matched. Then wc -l counts and prints the number of lines in its input.
result=`ps -Al | grep command-name | wc -l`
echo $result
ps -Al | grep -c bash
You can try :
ps -ef | grep -cw [p]rocess_name
OR
ps aux | grep -cw [p]rocess_name
For e.g.,:
ps -ef | grep -cw [i]nit
Some of the above didn't work for me, but they helped me on my way to this.
ps aux | grep [j]ava -c
For newbies to Linux:
ps aux prints all the currently running processes, grep searches for all processes that match the word java, the [] brackets remove the process you just ran so it wont include that as a running process and finally the -c option stands for count.
List all process names, sort and count
ps --no-headers -A -o comm | sort | uniq -c
You also can list process attached to a tty
ps --no-headers a -o comm | sort | uniq -c
You may filter with:
ps --no-headers -A -o comm | awk '{ list[$1] ++ } END { for (i in list) { if (list[i] > 10) printf ("%20s: %s\n", i, list[i]) } }'
Following bash script can be run as a cron job and you can possibly get email if any process forks itself too much.
for i in `ps -A -o comm= --sort=+comm | uniq`;
do
if (( `ps -C $i --no-headers | wc -l` > 10 )); then
echo `hostname` $i `ps -C $i --no-headers | wc -l` ;
fi
done
Replace 10 with your number of concern.
TODO: "10" could be passed as command line parameter as well. Also, few system processes can be put into exception list.
You can use ps(will show snapshot of processes) with wc(will count number of words, wc -l option will count lines i.e. newline characters).
Which is very easy and simple to remember.
ps -e | grep processName | wc -l
This simple command will print number of processes running on current server.
If you want to find the number of process running on current server for current user then use -U option of ps.
ps -U root | grep processName | wc -l
change root with username.
But as mentioned in lot of other answers you can also use ps -e | grep -c process_name which is more elegant way.
ps aux | wc -l
This command shows number of processes running on the system by all the users.
For a specific user you can use the following command:
ps -u <username> | wc -l
replace with the actual username before running :)
ps -awef | grep CAP | wc -l
Here "CAP" is the word which is in the my Process_Names.
This command output = Number of Processes + 1
This is why When we are running this command , our system read thats "ps -awef | grep CAP | wc -l " is also a process.
So yes our real answer is (Number of Processes) = Command Output - 1
Note : These processes are only those processes who include the name of "CAP"
Related
I want get the run times of some processes. Here is what I am doing
ps -ef | grep "python3 myTask.py" | awk '{print $2}' | xargs -n1 ps -p {} -o etime
I want to get the pids by
ps -ef | grep "python3 myTask.py" | awk '{print $2}'
then pass these along to the
ps -p {} -o etime
by using xargs, but its not working. I get
error: process ID list syntax error
Usage:
ps [options]
Try 'ps --help <simple|list|output|threads|misc|all>'
or 'ps --help <s|l|o|t|m|a>'
for additional help text.
For more details see ps(1).
error: process ID list syntax error
Usage:
ps [options]
Try 'ps --help <simple|list|output|threads|misc|all>'
or 'ps --help <s|l|o|t|m|a>'
for additional help text.
For more details see ps(1).
what am i doing wrong?
You can use the following command:
pgrep -f "python3 myTask.py" | xargs -i{} ps -p {} -o etime
pgrep - Look up or signal processes based on name and other attributes.
-f, --full -
The pattern is normally only matched against the process name. When -f is set, the full command line is
used.
For further reading, see man pgrep.
The missing part from the xargs segment was -i{}, which invokes the command for each argument, whilst {} will be replaced by it.
-i[replace-str], --replace[=replace-str] -
This option is a synonym for -Ireplace-str if replace-str is specified.
For further reading, see man xargs.
You must provide -I{} to xargs to set the placeholder; otherwise it cannot be used.
Nevertheless, your command is too complicated and involves too many intermediate steps (and a race-condition). Simply get your processes including elapsed time and filter the lines you need:
ps -eo etime,cmd | awk '/python3 myTask.py/{print $1}'
(no xargs anymore)
does anyone know how I can pipe the results of ps -ef | grep ^$USER to wc -1
I already used ps -ef | grep ^$USER but know i want to pipe the command
As per my understanding of your question
you want all the running process from a particular user and pipe it to wc ( note its wc -l not -1)
so i used this
ps aux | grep ^$USER|wc -l
-a : Information for all processes associated with terminals.
-u : Information for processes in userlist.
-x : username (user running this command)
or this can also work
ps -u $USER|wc -l
for any commands if you want to know the details try man command in terminal for example man ps
I want to monitor the number of file descriptors opened by a process running on my centos box. the below command works for me
watch -n 1 "ls /proc/pid/fd | wc -l"
The problem comes when I need to monitor the same when the above process is restarted. The pid changes and I cant get the stats.
The good thing is that the pname is constant. So I can extract the pid using pgrep pname.
So how can I use the command in the below way:
watch -n 1 "ls /proc/"pgrep <pname>"/fd | wc -l"
I want the pgrep pname value to be dynamically picked up.
Is there any way I can define a variable which continuously gets the latest value of pgrep pname and I can insert the variable here.
watch evaluates its command as shell command each time, so we first have to find a shell command that produces the output. Since there may be multiple matching processes, we can use a loop:
for pid in $(pgrep myprocess); do ls "/proc/$pid/fd"; done | wc -l
Now we can quote that to pass it literally to watch:
watch -n 1 'for pid in $(pgrep myprocess); do ls "/proc/$pid/fd"; done | wc -l'
watch -n 1 "pgrep memcached | xargs -I{} ls /proc/{}/fd | wc -l"
Another one way.
I'm looking at a way to automate the following:
Run ps -ef to list all processes.
Filter out those rows containing java in the CMD column.
Filter out those rows containing root in the UID column.
For each of the filtered rows, get the PID column and run pargs <PID>.
If the output of pargs <PID> contains a particular string XYZ, the issue a kill -9 <PID> command.
To filter out rows based on specific column values, is there a better way than grep? I can use
ps -ef | awk '{print $1}' | grep <UID>
but then I lose info from all other columns. The closest thing I have right now is:
ps -ef | grep java | grep root | grep -v grep | xargs pargs | ?????
EDIT
I was able to solve the problem by using a using the following script:
ps -ef | awk '/[j]ava/ && /root/ {print $2}' | while read PID; do
pargs "$PID" | grep "Args" > /dev/null && kill -9 $PID && echo "$PID : Java process killed!"
done
both anubhava's and kojiro's answers helped me reach there. But since I can only accept one answer, I tagged kojiro's answer as the correct one since it helped me a bit more.
Consider pgrep:
pgrep -U 0 java | while read pid; do
pargs "$pid" | grep -qF XYZ && kill "$pid"
done
pgrep and pkill are available on many Linux systems and as part of the "proctools" packages for *BSDs and OS X.
You can reduce all grep by using awk:
ps -ef | awk '/[j]ava/ && /root/ {print $1}' | xargs pargs
Searching for pattern /[j]ava/ will skip this awk process from output of ps.
You can also use pkill if it is available on your system.
I want to use ps -ef | grep "keyword" to determine the pid of a daemon process (there is a unique string in output of ps -ef in it).
I can kill the process with pkill keyword is there any command that returns the pid instead of killing it? (pidof or pgrep doesnt work)
You can use pgrep as long as you include the -f options. That makes pgrep match keywords in the whole command (including arguments) instead of just the process name.
pgrep -f keyword
From the man page:
-f The pattern is normally only matched against the process name. When -f is set, the full command line is used.
If you really want to avoid pgrep, try:
ps -ef | awk '/[k]eyword/{print $2}'
Note the [] around the first letter of the keyword. That's a useful trick to avoid matching the awk command itself.
Try
ps -ef | grep "KEYWORD" | awk '{print $2}'
That command should give you the PID of the processes with KEYWORD in them. In this instance, awk is returning what is in the 2nd column from the output.
ps -ef | grep KEYWORD | grep -v grep | awk '{print $2}'
This is available on linux: pidof keyword
I use
ps -C "keyword" -o pid=
This command should give you a PID number.
To kill a process by a specific keyword you could create an alias in ~/.bashrc (linux) or ~/.bash_profile (mac).
alias killps="kill -9 `ps -ef | grep '[k]eyword' | awk '{print $2}'`"