Questions tagged [grep]
grep is a command-line tool for searching text patterns in files.
298
questions
1
vote
1answer
24 views
Append to crontab only if entry does not exist
I am looking for a programmatic way to append to crontab only if the entry does not exist. Also, the exit code must be 0 for both cases where the entry does not exist, or the entry exists.
I tried:
(...
0
votes
1answer
24 views
netstat how to exclude localhost from the result when using grep
When I run this command in my terminal:
netstat -an | egrep ":80|:443" | sort
I got this following output:
tcp 0 0 172.104.10.125:48310 172.104.10.125:8081 TIME_WAIT
tcp ...
0
votes
0answers
17 views
Reverse grep with whitelist
I would like to parse the output of a command with a whitelist that, in case even one symbol is found in a line that is not in the white list it should be assigned to the variable, something like this:...
0
votes
1answer
27 views
How to grep lines only with matched words in Linux [closed]
I have a little question.
I have a list of processes.
After this command
ps aux | grep postgres
I see
postgres 1178 0.0 0.2 320064 27060 ? S Apr12 0:05 /usr/lib/postgresql/10/bin/...
0
votes
2answers
34 views
How to remove old kernel on Ubuntu operating system
I am wondering how can I do remove old kernel from Ubuntu operating system.
Please refer image screenshot taken. Please advice. Many thanks.
list of linux kernel
1
vote
1answer
26 views
How to quickly check if specific keywords exist in a lot of log files in shell?
I have run a program that writes a lot of log files in a lot of directories.
For example, there are hundreds directories, and every one includes thousands of log files.
I need to find out the files ...
0
votes
1answer
48 views
check ip is present and update iptables openvpn
I want to check that the ip is present within the ccd folder and push the ip route to the FORWARDING chain in the iptables. Im new to bash scripting and need a little help finishing this script.
...
0
votes
2answers
40 views
Extract string from column with grep
I have a column based .txt file and I want to grep output the Common Name, having a little trouble.
V 300223164711Z 01 unknown /C=UK/O=LMG/OU=server/CN=server/name=server/emailAddress=...
0
votes
1answer
38 views
Script to grep large file [closed]
I have a file that has about 63000 row I need to grep though
[root@server]# cat missinglinks.txt
69870 1.pdf.Published
125098 2.png.Published
125022 3.pdf.Published
69867 4.png.Published
I have a ...
0
votes
1answer
27 views
How to print only Users list and Access level from /etc/sudoers?
We have multiple servers and i would like to print users list and access level using bash.
I tried below command but could not get exact result what i wanted to:
awk '/Allow root/{p=5} p > 0 {...
0
votes
2answers
46 views
How to filler out iptable result base on certain fields and view it with tail command?
I have this log :
Jan 26 01:05:47 server54 kernel: [41s58.6w4335] INPUT:DROP: IN=eth4 OUT= MAC=d3:ss:43:23:23:43 SRC=1.1.1.1 DST=127.0.0.0 LEN=40 TOS=0x00 PREC=0x00 TTL=254 ID=65259 PROTO=TCP SPT=...
0
votes
0answers
37 views
View 503 errors in real time?
I know I can use tail -f /access.log to view my log file in real time.
Can I use tail or grep or some sort of combinations to only view 503 errors in real time within that log file?
0
votes
0answers
28 views
Creating a script for Kickstarting servers; issue with created softraid 1 server based on CentOS 7
First off; I am sorry if my title is incorrect, but I didn't want to "clutter" it too much.
I am creating a bash script which is used to install various servers based on CentOS 6 and CentOS 7 with ...
0
votes
1answer
250 views
From a string, formatted as a table with spaces, how to grep all values that are equal for all columns?
The question comes from the issue:
https://github.com/kubernetes/kubectl/issues/717
Kubectl returns information in a table like this:
$ kubectl get replicasets -n kube-system
NAMESPACE NAME ...
0
votes
1answer
30 views
Filter ss process output without using grep
ss -p can give the process name, process id (PID) and the file descriptor associated with the connection.
Example: ss -tuanp
[...]
tcp ESTAB 0 0 x.x.x.x:59594 x.x.x.x:993 users:(("...
0
votes
1answer
203 views
Not logic in docker filter
I have a named container that may or may not be up and if it is up I want to be able to kill all the containers but that one by name.
Basically what I want is:
docker kill $(docker ps -aq --filter="...
0
votes
2answers
121 views
Parse Date from Text String in a 3 column format
I am given an array of lines from a text file. They look similar to this, and will always be structured like this:
Full Tue Aug 27 10:59:43 2019 1
...
1
vote
0answers
36 views
Why is sudo password entering lost
When I use sudo command and pipe it to another command, e.g.
sudo dnf search foo | grep bar
there is a prompt requiring to enter the password. Following this answer, sudo directly accesses the ...
0
votes
1answer
100 views
grep for an array entry in a file
so I have a file step1 containing data like
field [T]:0.000
heatstart [s]: 1.50E+1
a[a],b[b],[c[c],d
1.02E-1,2.31E-1,...
1.50E+1,4.26E-1,...
...
and a file called var4 containing only the entry 1....
0
votes
1answer
43 views
How to create an alias that uses a value and grep on a remote server?
I need help, I can't create an alias with a variable to grep a file on a remote server.
I have tried:
alias searchword="ssh -t user@server "grep -i \"$1\" /root/file.txt\""
alias search="ssh -t ...
0
votes
2answers
147 views
grep exclude multiline pattern
Searching for multiline patterns in files with grep is trivial. Inverting that pattern not so much.
Background: I want to create clean variable files without passwords so I can commit them into a ...
0
votes
1answer
188 views
How do I grep last match in a range of files?
I have files named memOutput.X where X ranges from 0 to 47 in a directory. I want to see the line with the last occurrence of VmData in all these files. I can run
grep VmData memOutput.0 | tail -1
...
1
vote
3answers
45 views
text processing linux using grep awk or anything else
I want to replace in this string Wed Apr 10 06:44:10 UTC 2019 all whitespaces with comma and along with that trim off UTC part.
What I have tried :
var1="Wed Apr 10 06:44:10 UTC 2019"
echo ${var// /,...
0
votes
1answer
45 views
get a specific line from in linux using grep
Hello I am new to linux and grep and awk commands.
I am trying to get the number value from this string variable and then store it in another variable.
var1="Version must be incremented on update. ...
2
votes
1answer
55 views
Cygwin 2.9.0 cat/tac Commands Fail on Large Files when Piping to grep -q -m1
I am seeing some odd behavior using Cygwin x64 2.9.0 on Windows 10 Pro x64. The command I am attempting to run is the following:
tac <file> | grep -q -m1 -F "literal string"
The above command ...
1
vote
2answers
537 views
Send email if script outputs string
I found this line:
sh script.sh | grep 'NO' 2>&1 > grep.log && /usr/bin/mail -s "grep found something" m@mail.com < grep.log
which will write the output of script.sh to grep.log ...
0
votes
2answers
165 views
Any way to avoid using `grep -v`
When performing a grep filtering across pipes, as in the following example,
$ ps -ef | grep 24604
username 18660 24604 0 16:38 pts/3 00:00:00 ps -ef
username 18661 24604 0 16:38 pts/3 ...
0
votes
1answer
227 views
Grep returns nothing
This is the grep command I used
grep -ic address log*
The output is 0.
I know for a fact that there are more than 60 occurrences of the word address in the log file. But I still get 0.
Now, I ...
1
vote
1answer
1k views
How can I use an iperf output and only grep Interval and Bandwidth?
I am trying to get the output from the command
iperf -c 10.0.0.1 -t 3600 -i 2
And only need the Interval and bandwidth fields listed for the entire hour of logging.
I haven't used grep or awk in ...
-1
votes
1answer
35 views
Apache Logs - identify IP that made series of specific requests
Given the following apache access log:
127.0.0.1 - - [04/May/2018:11:19:03 +0300] "GET /file1 HTTP/1.1" 200 ...
127.0.0.1 - - [04/May/2018:11:19:03 +0300] "GET /file1 HTTP/1.1" 200 ...
127.1.1.1 - - ...
-2
votes
1answer
26 views
finding a string among several zipped files (webapps)
We have to find a string, let's say "foobar" among several webapps.
However, some webapps contain zipped files, eg log4j.jar.
Therefore, grep -IR "foobar" /pathto/tomcatroot/ won't work, because of ...
1
vote
3answers
905 views
Grep last match from file
I'm running the following command against a log file and only wanting to get the last/latest match. Sometimes there may only be one match, other times there may be multiple, which is causing an issue ...
0
votes
1answer
318 views
grep multiple occurrences with intervening lines
I'd like to do the following:
Given a file with many lines, several of which match a pattern, output the first matching line, the last matching line, and all the lines in between (I want them in ...
1
vote
1answer
597 views
Grep --only-match without new line
I want to use grep command to extract some strings from my data file.
data file format
a=1,b=2,c=3,
a=4,b=5,c=6,
I want the out format
a=1,c=3,
a=4,c=6,
I tried the below command
grep -Po 'a=.*?...
7
votes
5answers
5k views
Calculate sum of several sizes of files in Bash
I have list of files in a file, cache_temp.
In file cache_temp:
/home/maildir/mydomain.com/een/new/1491397868.M395935P76076.nm1.mydomain.com,S=1740,W=1777
/home/maildir/mydomain.com/een/new/...
1
vote
1answer
552 views
grep does not work in particular folder on centos?
It's a bit strange with the grep command. When I am in the mail folder, it always produces help text. At first, I thought I had wrong synxtax but it is working on its parent folder.
What could be the ...
4
votes
2answers
504 views
How to show specific luns from lsscsi command?
I need to grep specific luns from the lsscsi command.
For example:
[root@e15l1 ~]# lsscsi 4 0 1 | awk '{print $1,$6}' | head
[4:0:1:0] -
[4:0:1:1] /dev/sdab
[4:0:1:2] /dev/sdj
[4:0:1:3] /dev/sdz
[4:...
3
votes
2answers
4k views
Ansible yum update then email me the results
Writing a playbook to perform yum updates and then get an email from each server. I'd like the email to contain the changed contents of yum.log.
IOW, I want the results of:
grep [today's date] /var/...
0
votes
1answer
488 views
Grepping a single line from iftop
iftop -t -L1 -s1
Output:
iftop -t -L1 -s1 | grep "Total send and receive rate:"
Output:
How can I grep just the "Total send and receive state:" line?
0
votes
1answer
487 views
Argument list too long with grep
Normally to search and replace a string in a selection of files, I would find with:
grep -rl 'pattern' .
This works fine unless you have a LOT of matches.
Anyway, I was looking around and found a ...
1
vote
0answers
330 views
Legal Discovery - how to search .eml files for keywords and copy the results to another folder on macOS/Unix?
I've got a Kerio Connect mail server that saves all of it's emails in a relatively standard mail spool folder structure as raw .eml files. I've been tasked with performing a keyword search against ...
0
votes
1answer
990 views
Trying to do grep and sed from a file and push the output into a variable
Can we do grep and sed from a file and push the output into a variable
grep "^/dev/disk/by-id/scsi-*" /tmp/disks.txt | sed '{'s/=.*//'}'
Output would be like this:
/dev/disk/by-id/scsi-...
-1
votes
1answer
686 views
Why grep doesn't work in the /usr/lib/systemd/system directory?
The other day I was on a RHEL7.1 system and I wanted to search for a specific word in the /usr/lib/systemd/system directory where all the systemd unit files are located.
I used the grep command as ...
-1
votes
1answer
83 views
how do i remove local ip from list of ip addresses?
I have a variable that contains list of ips and i will like to remove the ip of the instance where the variable is set
Please see below
[root@ip-10-10-2-100 ~]# INSTANCE_IP=$(curl -s http://169.254....
-2
votes
1answer
93 views
Listing all packages, but without addional text
In this time I am working of project, what tell you, what software you have installer and what you can install. In this time I have problem with this command: grep -hn Package: /var/lib/apt/lists/* . ...
2
votes
1answer
38 views
How to signal the presence of a pattern via exit code, without altering STDOUT
I need to run cmd1. If and only if PATTERN is missing from its STDOUT, i need to run cmd2 too:
cmd1 | grep "$PATTERN" || cmd2
But I'd like to see all output from cmd1, not just the lines that ...
0
votes
1answer
292 views
More elegant ps aux | grep [g]rep do not work
I am running the command: ps -ef | grep [p]ts/1
The result is:
root 13820 1733 0 14:19 ? 00:00:00 sshd: root@pts/1
root 13822 13820 0 14:19 pts/1 00:00:00 -bash
root 15847 ...
1
vote
0answers
513 views
Grep - Looking for non printable or higher range ascii characters
We faced an issue when someone copied a string from somewhere in one of the metadata xml files that contained ascii characters 239 (0xef), 191 (0xbf), 189 (0xbd)
We fixed the problem in known file, ...
2
votes
3answers
4k views
Cron: only send mail if output contains string
Can I make cause cron to only send the email if the output (stderr) contains a certain string?
I'm aware of this answer but the command I run doesn't distinguish between stdout/stderr, it always just ...
2
votes
1answer
10k views
Escaping special characters in grep regex
I am trying to run a grep regular expression on a file, where I have to exclude lines where "00" and "0" appear. I came up with this expression:
grep -a -E \"stored\"\:\ \"\*123\*(?!00)[0-9]{2,5}\#\" ...
