I have for loop:
for mnt `cat $file.txt`
do
grep -h -i -A 3 -B 4 *log | grep -v "10001" >> extrafile.txt
done
What does -A 3 and -B 4 means?
After and Before followed by number of lines
After en Before. After and before what?
No wonder the grep is confusing: You don't mention the "${mnt}" you are searching for. When I improve your script (moving input and output to the end, outside the loop, and using ${mnt}), the script looks like
while read -r mnt; do
grep -h -i -A 3 -B 4 "${mnt}" *log | grep -v "10001"
done < "${file.txt}" >> extrafile.txt
You get the context of every hit from $file.txt and delete all lines with 10001.
Related
How can pipes and grep and wc be combined to just give a count of the phrase “syntax ok”
Something like the following…
cd /usr/IBMIHS/bin/ |
apachectl -t -f /usr/IBMIHS/conf/AAA/httpd.conf |
apachectl -t -f /usr/IBMIHS/conf/AAA/siteAA.conf |
grep "^Syntax OK" | wc
Simply via grouping commands with curly brackets, and use grep -c:
{
apachectl -t -f /usr/IBMIHS/conf/AAA/httpd.conf
apachectl -t -f /usr/IBMIHS/conf/AAA/siteAA.conf
} |& grep -c "Syntax OK"
From man grep
-c, --count
Suppress normal output; instead print a count of matching lines for each input file. With the -v, --invert-match option (see below), count non-matching lines.
I am having some difficulty finding the number of hex characters in a file. For example:
grep -o \x02 file | wc -l
0
There should be about 3M matches here, but it doesn't seem like the \x02 character is being recognized here. For example (in python):
>>> s=open('file').read()
>>> s.count('\x02')
2932267
The answer by Mark Setchell may be OK for MacOS but doesn't seem to work on debian using bash (tested with bash 4.4, grep 2.27).
I could get a match using the -P directive (for Perl regex)
user#host:~ $ printf '\x02\n3\n\x02' | grep -c -P '\x02'
2
user#host:~ $ printf '\x02\n3\n\x02' | grep -c -P '\xFF' #same input, different pattern
0
user#host:~ $ printf '\x02\n3\n\xff' | grep -c -P '\xFF' #match with unmatching case
2
Hope this helps
This seems to do what you want on macOS:
printf "\x02\n3\n\x02" | grep -c "\x02"
2
I have a directory that has one file with information (call it masterfile.inc) and several files that are empty (call them file1.inc-file20.inc)
I'm trying to formulate an xargs command that copies the contents of masterfile.inc into all of the empty files.
So far I have
ls -ltr | awk '{print $9}' | grep -v masterfile | xargs -I {} cat masterfile.inc > {}
Unfortunately, all this does is creates a file called {} and prints masterfile.inc into it N times.
Is there something I'm missing with the syntax here?
Thanks in advance
You can use this command to copy file 20 times:
$ tee <masterfile.inc >/dev/null file{1..20}.inc
Note: file{1..20}.inc will expand to file1, file2, ... , file20
If you disternation filenames are random:
$ shopt -s extglob
$ tee <masterfile.inc >/dev/null $(ls !(masterfile.inc))
Note: $(ls !(masterfile.inc)) will expand to all file in current directory except masterfile.inc (please don't use spaces in filename)
While the tee trick is really brilliant you might be interested in a solution that is easier to adapt for other situations. Here using GNU Parallel:
ls -ltr | awk '{print $9}' | grep -v masterfile | parallel "cat masterfile.inc > {}"
It takes literally 10 seconds to install GNU Parallel:
wget pi.dk/3 -qO - | sh -x
Watch the intro videos to learn more: https://www.youtube.com/playlist?list=PL284C9FF2488BC6D1
On unix, how could we know whether the system is multiprocessor or uniprocessor?
Some times we have to answer owr own question :)
On Solaris run the command
/usr/sbin/psrinfo -v|grep "Status of processor"|wc -l
On AIX run the command
lsdev -C|grep Process|wc -l
On HP-UX run the following commands (requires superuser privileges):
P=`echo processor_count/D | adb -k /stand/vmunix /dev/mem |tail -1|awk '{print $2}'` echo "The number of processors on `hostname` = $P"
On Tru64 run the command
/usr/sbin/psrinfo -v|grep "Status of processor"|wc -l
How about
cat /proc/cpuinfo | grep -i 'processor' | wc -l
Or even
dmesg | grep -i cpu
Look out for "Brought up x processors" in the last one
I don't know if it applies to Unix as well, but for Linux, from command line, see here: http://www.howtogeek.com/howto/ubuntu/display-number-of-processors-on-linux/
I'm using AWS CodeDeploy in which server running on pm2 dose not work due to explanation given here in troubleShoot documentation.
I followed the documentation and in AfterInstall script used node . > /dev/null 2> /dev/null < /dev/null & to run the node server in the background.
I've tried following ways to kill the server
fuser -k 3000/tcp
lsof -P | grep ':3000' | awk '{print $2}' | xargs kill -9
kill -9 $(lsof -t -i:3000)
but each time a new process respwans with a different PID.
How can I kill this background process and add it to the ApplicationStop script for CodeDeploy?
One of the problems with finding a pid with grep is that the grep pid will also show up as a result and can kill itself before the target, so try;
ps ax | grep node | grep -v grep
if it looks reasonable, review this;
ps ax | grep node | grep -v grep | awk '{print $1}'
then run the kill;
ps ax | grep node | grep -v grep | awk '{print $1}' | xargs kill -9
pkill is a less flexible option (no regex filtering) but if you use that be sure to use the -I flag so you don't kill anything you did not intend to.
I was able to kill using pkill node command.