New to shell scripting and just writing a little script to check if a process is running, if I use
PROCESS_NUM="ps -ef | grep '$1' | grep -v 'grep' | wc -l"
I get a "ps: illegal argument: |" error although if I echo out PROCESS_NUM and ctrl paste in the line it works just fine manually. Not sure why the | pipe is being troublesome here. Any help is much appreciated!
If you are trying to assig the output of ps -ef | grep '$1' | grep -v 'grep' | wc -l command to PROCESS_NUM variable, you need to use below:
PROCESS_NUM=`ps -ef | grep '$1' | grep -v 'grep' | wc -l`
or
PROCESS_NUM=$(ps -ef | grep '$1' | grep -v 'grep' | wc -l)
Using "", will treat the value inside of it as a string, except for some special character
Related
When I run the following command in my terminal I get the expected value :
delayedjobs="$(ps aux | grep delayed_job | grep -v grep | awk '{print $11}' | awk 'END{print}' | cut -d "." -f2)" && echo $delayedjobs
However, when I run the following script, the variable returns as "/bin/bash"
#!/bin/bash
delayedjobs="$(ps aux | grep delayed_job | grep -v grep | awk '{print $11}' | awk 'END{print}' | cut -d "." -f2)"
echo ${delayedjobs}
root#central:/home/tblake# ./myscript.sh
/bin/bash
Can anyone explain this? Im having a heck of a time figuring this out.
Has you named your skript delayed_job ? Your script detect his own process.
I'm trying to kill process by name. It's supposed to kill children processes first then the parent later but I only get parent killed. Help needed please. EDIT: SOLVED
Please try it this way:
PID=$(ps -aef | grep `whoami` | grep $argument | grep -v grep | grep -v $$ | awk '{print $2}'
for x in ${PID[#]}; do
CPID=$(ps -aef | grep `whoami` | grep $PID | grep -v grep | grep -v $$ | awk '{print $3}'
for y in ${CPID[#]}; do
kill $y
done
kill $x
done
Following is my script, every time I run this it goes into else part. when I run the TEST2EVAL command it gives me 1
#!/bin/sh
TEST2EVAL='ps auxf | grep some.jar | grep -v grep | wc -l'
if [ "$TEST2EVAL" = 1 ]
then
java -jar /path/to/jar &
else
echo "Running"
fi
Assuming you are trying to find out if any processes are running with some.jar on their command lines you probably want:
if pgrep -f some.jar; then
echo running;
else
echo not running;
fi
In in order save the output of a command in a variable, you have to enclose the command in backticks (`), not single quotes ('). Thus, change the second line of your script to:
TEST2EVAL=`ps auxf | grep some.jar | grep -v grep | wc -l`
You are using the wrong quotes for command substitution: not single quotes:
TEST2EVAL='ps auxf | grep some.jar | grep -v grep | wc -l'
but backquotes:
TEST2EVAL=`ps auxf | grep some.jar | grep -v grep | wc -l`
Better yet, use TEST2EVAL=$(ps auxf | grep some.jar | grep -v grep | wc -l) instead. It's much clearer, supported by all POSIX-compatible shells, and can be nested more easily when necessary.
I have a very basic script that keeps spitting back that the commands are not found. Ive looked all over this site and can not find an answer that works for me. The path to bash is correct. Ive checked the script with od. Ive run dos2unix. None of this helps me.
SCRIPT:
#!/bin/bash
HYBRISPROC=`ps -eo pid,command | grep [h]ybris | grep -v grep | awk '{print $1}'`
echo "Looking for Hybris..."
echo $HYBRISPROC
RESULTS:
./HybrisStopStart.sh: line 5: ps: command not found
./HybrisStopStart.sh: line 5: grep: command not found
./HybrisStopStart.sh: line 5: awk: command not found
./HybrisStopStart.sh: line 5: grep: command not found
Looking for Hybris...
Any ideas? If I run the command just on its own it works fine. Ive tried it as sudo as well and et the same results.
TIA
How about it?
#!/bin/bash
HYBRISPROC=`ps -eo pid,command | grep [h]ybris | grep -v grep | awk '{print $1}'`
echo "Looking for Hybris..."
echo "$HYBRISPROC"
(OR)
#!/bin/bash
HYBRISPROC="ps -eo pid,command | grep [h]ybris | grep -v grep | awk '{print $1}'"
echo "Looking for Hybris..."
bash -c "$HYBRISPROC"
(OR)
#!/bin/bash
HYBRISPROC="ps -eo pid,command | grep [h]ybris | grep -v grep | awk '{print $1}'"
echo "Looking for Hybris..."
eval "$HYBRISPROC"
TOTALY:
you can see the difference:
#!/bin/bash
LS=`ls -l`
echo $LS #nasty way
echo
echo "$LS" #good way
Try to add
PATH="$PATH:/usr/bin:/bin"
before code. Looks like bin directory is not on your path. So the commands are not found.
I am writing a script to kill all instances of the same process. As it is going to be used on Linux, AIX, HP-UX and Solaris, I need to use only built-in bash (sh) functions. That's why killall, pkill, etc. don't work for me.
Once there is only one instance of a process it should be just killed in traditional way:
kill -TERM `ps -ef | grep -v grep | grep $process | awk '{print $2}'`
However sometimes the program has extra instances running and that's why ps -ef | … returns more than one PID. That needs to be reported.
example:
bash-3.2$ ps -ef | grep -v grep | grep perl | awk '{print $2}'
5267
5268
5269
5270
5271
My thought was to store those values in a temporary variable and then send kill signal to each in a for loop.
bash-3.2$ tmp=`ps -ef | grep -v grep | grep perl | awk '{print $2}'`
bash-3.2$ echo $tmp
5267 5268 5269 5270 5271
However I still need the information if such a case occurred (how many instances were present).
It seems I need to check the whole string stored in the tmp variable and maybe count spaces?
Anyway the questions reduces to how to check how many values the $tmp variable stores?
For maximum portability and reliability, use -A (POSIX synonym of -e) and a custom format with -o rather than -f.
Your filtering of the output of ps is brittle: it may match other processes. You've had to exclude the grep process, and you may need to exclude your script as well, and there may be other completely innocent processes caught in the fray (such as your script itself) because their command line happens to contain $process as a substring. Make your filtering as strict as possible. With ps -o pid= -o comm=, you get just two columns (PID and command without arguments) with no header.
You don't need to use a loop to do the killing, kill accepts multiple arguments. For the counting, let the shell do it: you have a whitespace-separated list of numbers, to let the shell do the word splitting (with $(…) outside quotes) and count the number of resulting words ($#).
count_and_kill_processes () {
set -- $(ps -A -o pid= -o comm= |
awk -v "name=$process" '$2 == name {print $1}')
count=$#
if [ $# -ne 0 ]; then kill "$#"; fi
}
count_and_kill_processes foo
# now the number of killed processes is in $count
If your shell is bash or ksh on all machines, you can use an array.
pids=($(ps -A -o pid= -o comm= |
awk -v "name=$process" '$2 == name {print $1}') )
if [[ $# -ne 0 ]]; then kill "$#"; fi
# the number of killed processes is ${#pids}
use xargs:
ps aux | grep -ie perl | awk '{print $2}' | xargs kill -9
You can use a loop which should work in both cases:
for pid in $(ps -ef | grep -v grep | grep $process | awk '{print $2}'); do
echo $pid
done
Or count the number of matches:
if [ $(ps -ef | grep -v grep | grep $process | awk '{print $2}' | wc -l) -gt 1 ]
then
# more than one
fi