Commands using grep (1,935)

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Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Read all the S.M.A.R.T. data from a hard disk drive
This is to pull all the saved S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) information from a hard drive. This can give you an idea of the nature and extent of an issue on a failing hard drive.

sort lines by length

journalctl -f
a tail -f variant of systemd journal. Follow the most recent updates or if events are appended to the journal

Take a screenshot every 2 seconds
Take a screenshot every 2 seconds and save it as a png file

Export a subset of a database
Limits the number of rows per table to X

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Get information about memory modules
To take information about the characteristics of the installed memory modules.

Do command when logged in from certain ips using ssh
Place in ~/.bashrc If you login to a ssh server from different ips, sometimes you want to do something specific for each. e.g., quickly go into screen -x session from a phone, but not your desktop.

Apply substitution only on the line following a marker
I've been auto-generating some complex GnuPlots; with multiplots the first plot of each group needs to be a 'plot' whereas the others need to be 'replots' to allow overplotting/autoscaling/etc to work properly. This is used to replace only the first instance of 'replot'.


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