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1500 questions
69
votes
10 answers
Linux: using find to locate files older than
find has good support for finding files the more modified less than X days ago, but how can I use find to locate all files modified before a certain date?
I can't find anything in the find man page to do this, only to compare against another files…
DrStalker
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69
votes
6 answers
Sending cron output to a file with a timestamp in its name
I have a crontab like this on a LAMP setup:
0 0 * * * /some/path/to/a/file.php > $HOME/cron.log 2>&1
This writes the output of the file to cron.log. However, when it runs again, it overwrites whatever was previously in the file.
How can I get cron…
Philip Morton
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69
votes
1 answer
NMAP: Check if port 80 and 8080 is open
In our company, I want to check if users are running web servers on port 80 and 8080.
I downloaded nmap and ran this command:
nmap -p 80,8080 192.168.1.0-255
I got a list of IPs and tried to access them in my browser (EG: 192.168.1.1:8080) but…
Ian
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69
votes
11 answers
How do I check if Log4j is installed on my server?
I have read about security vulnerabilities related to Log4j.
How do I check if Log4j is installed on my server?
My specific servers use Ubuntu 18.04.6 LTS.
I have installed many third-party packages and maybe some of them contain it.
Is there a…
Uri
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69
votes
7 answers
Should websites live in /var/ or /usr/ according to recommended usage?
According to a guide on the Linux directory structure, /usr/ is for application files, and /var/ is for files that change (I assume this means "files that belong to the applications"). Is this correct?
If this is the case then I'm a little torn…
Nick Bolton
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68
votes
2 answers
Why does AWS recommend against public S3 buckets?
"We highly recommend that you never grant any kind of public access to your S3 bucket."
I have set a very granular public policy (s3:GetObject) for one bucket that I use to host a website. Route53 explicitly supports aliasing a bucket for this…
Andrew Johnson
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68
votes
3 answers
Is the PHP option 'cgi.fix_pathinfo' really dangerous with Nginx + PHP-FPM?
There has been a lot of talking about a security issue relative to the cgi.fix_pathinfo PHP option used with Nginx (usually PHP-FPM, fast CGI).
As a result, the default nginx configuration file used to say:
# NOTE: You should have…
Totor
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68
votes
3 answers
Search ec2 instance by its name from aws command line tool
I have an instance named dev-server-03. Now how can I search all dev-server-* instances from command line?
I am using aws cli tool.
Shiplu Mokaddim
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- 2
- 9
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68
votes
4 answers
How can I get more info on open pipes show in /proc in Linux?
In Linux if you go digging in /proc//fd often you'll see output like:
lrwx------ 1 root root 64 Jul 30 15:14 0 -> /dev/null
lrwx------ 1 root root 64 Jul 30 15:14 1 -> /dev/null
l-wx------ 1 root root 64 Jul 30 15:14 10 ->…
Kamil Kisiel
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68
votes
9 answers
Convert from P7B to PEM via OpenSSL
On Ubuntu, I cannot convert certificate using openssl successfully.
vagrant@dev:/vagrant/keys$ openssl pkcs7 -print_certs -in a.p7b -out a.cer
unable to load PKCS7 object :PEM
routines:PEM_read_bio:no start line:pem_lib.c:696:Expecting:…
Kevin Meredith
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- 2
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68
votes
11 answers
Disable a service from starting at all runlevels?
I have a service foo which currently starts at runlevel 3 and above. How can I stop it from doing so, without using update-rc.d foo stop 3 ., which (if I understand it correctly) would turn off the service at each runlevel change.
(ie., if I was at…
lfaraone
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68
votes
8 answers
Is there a way to redirect output to a file without buffering on unix/linux?
I have a long running batch process that outputs some debug and process information to stdout.
If I just run from a terminal I can keep track of 'where it is' but then the data gets too much and scrolls off the screen.
If I redirect to output to a…
James Dean
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68
votes
3 answers
How do I enable non-free packages on Debian?
How can I enable non-free packages on Debian? I want to install Sun's Java JDK but it's not available to me.
Quiffner
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68
votes
2 answers
How to restart rsyslog daemon on ubuntu
how can i restart rsyslog or rsyslogd on ubuntu 10
root@terminator:/etc/init.d# service rsyslog status
rsyslog stop/waiting
root@terminator:/etc/init.d# service rsyslog stop
stop: Unknown instance:
root@terminator:/etc/init.d# service rsyslog…
John
68
votes
6 answers
How to check disk I/O utilization per process?
I'm having a problem with a Linux system and I have found sysstat and sar to report huge peaks of disk I/O, average service time as well as average wait time.
How could I determine which process is causing these peaks the next time it happen?
Is it…
Avada Kedavra
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