Running ps aux gives something along the lines of:
user 2222 0.0 0.0 24235 346323 ? s Apr08 0:00 /command value=4
In this case, I'm trying to capture the value of 'value'. I've tried
grep 'value' | ps aux | awk '{print $11}'
without success. Can anyone help out?
Assuming GNU grep
pgrep -fl 'command.*value' | grep -oP 'value=\K\S+'
run this command
ps aux |grep 'value' | awk '{print $12}'
remember when you pipe a command, the output goes from left to right.
I am using this command to get the process ID of another command:
ps aux | grep 7000.conf | awk '{print $2}'
This will return two PIDs:
7731
22125
I only want the first one. The second is the PID for grep in the above command. Thanks in advance to any one who knows how to alter the above command to return just the first pid.
p.s. open to a new command that does the same thing
In this particular case, escaping the . to what I assume it was meant to do should work:
ps aux | grep '7000\.conf' | awk '{print $2}'
Alternatively, exclude grep:
ps aux | grep 7000.conf | grep -v grep | awk '{print $2}'
ps aux | grep "[7]000.conf" will work as well.
Hi Can someone please let me know how I can calculate the output field from this command to MB ?
The command below shows the 20 largest file in directory and sub directories
but I need to convert the output to MB. In my script I use an array.. But If you guys show me how to use awk to divide the output for this by mega=1048576
I would really appreciate it .. Please explain the options !!!
ls -1Rs | sed -e "s/^ *//" | grep "^[0-9]" | sort -nr | head -n20 | awk {'print $1'}
Thanks
You don't show any sample input or expected output so this is a guess but this MAY be what you want (assuming you cant follow all the other good advice about not parsing ls output and you don't have GNU awk for internal sorting):
ls -1Rs | awk '/^ *[0-9]/' | sort -nr | awk 'NR<21{print $1/1024}'
Note that you don't need all those other commands and pipes when you're already using awk.
ls -1Rs | sed -e "s/^ *//" | grep "^[0-9]" | sort -nr | head -n20 | awk {'print $1 / 1024'} To turn it into MB - You have to divide it by 1024
I want to run pstree on a set of pid which I find using ps
ps -aux | grep ^username | awk '{pstree $2}'
Unfortunately, the output is empty, but if I run the pstree command manually with the same pids I get the desired output. What is wrong with the awk command? Or how do I achieve the desired result by other means?
Try
ps -aux | grep ^username | awk '{print $2}' | xargs pstree
(As is, pstree is an empty variable value )
This can can be boiled down to
ps -aux | awk '/^username/{print $2}' | xargs pstree
IHTH
use the system function in awk. Also you dont need grep here too
ps -aux | awk '$1=="username"{system("pstree $2")}'
Use system function in awk like this:
awk '{system("pstree " $2)}'
You can shorten your command to:
ps -aux | awk ' /^username/ { system("pstree " $2) }'
Is there any way to specify a field delimiter for more spaces with the cut command? (like " "+) ?
For example: In the following string, I like to reach value '3744', what field delimiter I should say?
$ps axu | grep jboss
jboss 2574 0.0 0.0 3744 1092 ? S Aug17 0:00 /bin/sh /usr/java/jboss/bin/run.sh -c example.com -b 0.0.0.0
cut -d' ' is not what I want, for it's only for one single space.
awk is not what I am looking for either, but how to do with 'cut'?
thanks.
Actually awk is exactly the tool you should be looking into:
ps axu | grep '[j]boss' | awk '{print $5}'
or you can ditch the grep altogether since awk knows about regular expressions:
ps axu | awk '/[j]boss/ {print $5}'
But if, for some bizarre reason, you really can't use awk, there are other simpler things you can do, like collapse all whitespace to a single space first:
ps axu | grep '[j]boss' | sed 's/\s\s*/ /g' | cut -d' ' -f5
That grep trick, by the way, is a neat way to only get the jboss processes and not the grep jboss one (ditto for the awk variant as well).
The grep process will have a literal grep [j]boss in its process command so will not be caught by the grep itself, which is looking for the character class [j] followed by boss.
This is a nifty way to avoid the | grep xyz | grep -v grep paradigm that some people use.
awk version is probably the best way to go, but you can also use cut if you firstly squeeze the repeats with tr:
ps axu | grep jbos[s] | tr -s ' ' | cut -d' ' -f5
# ^^^^^^^^^^^^ ^^^^^^^^^ ^^^^^^^^^^^^^
# | | |
# | | get 5th field
# | |
# | squeeze spaces
# |
# avoid grep itself to appear in the list
I like to use the tr -s command for this
ps aux | tr -s [:blank:] | cut -d' ' -f3
This squeezes all white spaces down to 1 space. This way telling cut to use a space as a delimiter is honored as expected.
I am going to nominate tr -s [:blank:] as the best answer.
Why do we want to use cut? It has the magic command that says "we want the third field and every field after it, omitting the first two fields"
cat log | tr -s [:blank:] |cut -d' ' -f 3-
I do not believe there is an equivalent command for awk or perl split where we do not know how many fields there will be, ie out put the 3rd field through field X.
Shorter/simpler solution: use cuts (cut on steroids I wrote)
ps axu | grep '[j]boss' | cuts 4
Note that cuts field indexes are zero-based so 5th field is specified as 4
http://arielf.github.io/cuts/
And even shorter (not using cut at all) is:
pgrep jboss
One way around this is to go:
$ps axu | grep jboss | sed 's/\s\+/ /g' | cut -d' ' -f3
to replace multiple consecutive spaces with a single one.
Personally, I tend to use awk for jobs like this. For example:
ps axu| grep jboss | grep -v grep | awk '{print $5}'
As an alternative, there is always perl:
ps aux | perl -lane 'print $F[3]'
Or, if you want to get all fields starting at field #3 (as stated in one of the answers above):
ps aux | perl -lane 'print #F[3 .. scalar #F]'
If you want to pick columns from a ps output, any reason to not use -o?
e.g.
ps ax -o pid,vsz
ps ax -o pid,cmd
Minimum column width allocated, no padding, only single space field separator.
ps ax --no-headers -o pid:1,vsz:1,cmd
3443 24600 -bash
8419 0 [xfsalloc]
8420 0 [xfs_mru_cache]
8602 489316 /usr/sbin/apache2 -k start
12821 497240 /usr/sbin/apache2 -k start
12824 497132 /usr/sbin/apache2 -k start
Pid and vsz given 10 char width, 1 space field separator.
ps ax --no-headers -o pid:10,vsz:10,cmd
3443 24600 -bash
8419 0 [xfsalloc]
8420 0 [xfs_mru_cache]
8602 489316 /usr/sbin/apache2 -k start
12821 497240 /usr/sbin/apache2 -k start
12824 497132 /usr/sbin/apache2 -k start
Used in a script:-
oldpid=12824
echo "PID: ${oldpid}"
echo "Command: $(ps -ho cmd ${oldpid})"
Another way if you must use cut command
ps axu | grep [j]boss |awk '$1=$1'|cut -d' ' -f5
In Solaris, replace awk with nawk or /usr/xpg4/bin/awk
I still like the way Perl handles fields with white space.
First field is $F[0].
$ ps axu | grep dbus | perl -lane 'print $F[4]'
My approach is to store the PID to a file in /tmp, and to find the right process using the -S option for ssh. That might be a misuse but works for me.
#!/bin/bash
TARGET_REDIS=${1:-redis.someserver.com}
PROXY="proxy.somewhere.com"
LOCAL_PORT=${2:-6379}
if [ "$1" == "stop" ] ; then
kill `cat /tmp/sshTunel${LOCAL_PORT}-pid`
exit
fi
set -x
ssh -f -i ~/.ssh/aws.pem centos#$PROXY -L $LOCAL_PORT:$TARGET_REDIS:6379 -N -S /tmp/sshTunel$LOCAL_PORT ## AWS DocService dev, DNS alias
# SSH_PID=$! ## Only works with &
SSH_PID=`ps aux | grep sshTunel${LOCAL_PORT} | grep -v grep | awk '{print $2}'`
echo $SSH_PID > /tmp/sshTunel${LOCAL_PORT}-pid
Better approach might be to query for the SSH_PID right before killing it, since the file might be stale and it would kill a wrong process.