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Show line numbers in a text file

Rename files in batch

Upgrading packages. Pacman can update all packages on the system with just one command. This could take quite a while depending on how up-to-date the system is. This command can synchronize the repository databases and update the system's packages.
Warning: Instead of immediately updating as soon as updates are available, users must recognize that due to the nature of Arch's rolling release approach, an update may have unforeseen consequences. This means that it is not wise to update if, for example, one is about to deliver an important presentation. Rather, update during free time and be prepared to deal with any problems that may arise. Pacman is a powerful package management tool, but it does not attempt to handle all corner cases. Read The Arch Way if this causes confusion. Users must be vigilant and take responsibility for maintaining their own system. When performing a system update, it is essential that users read all information output by pacman and use common sense. If a user-modified configuration file needs to be upgraded for a new version of a package, a .pacnew file will be created to avoid overwriting settings modified by the user. Pacman will prompt the user to merge them. These files require manual intervention from the user and it is good practice to handle them right after every package upgrade or removal. See Pacnew and Pacsave Files for more info. Tip: Remember that pacman's output is logged in /var/log/pacman.log.

Delete recursively only empty folders on present dir

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"

Find Duplicate Files (based on size first, then MD5 hash)
This dup finder saves time by comparing size first, then md5sum, it doesn't delete anything, just lists them.

Extract multiple tar files at once in zsh
tar doesn't support wildcard for unpacking (so you can't use tar -xf *.tar) and it's shorter and simpler than for i in *.tar;do tar -xf $i;done (or even 'for i in *.tar;tar -xf $i' in case of zsh) -i says tar not to stop after first file (EOF)

New Maintainer for CommandLineFu
Welcome to Jon H. (@fart), the new maintainer of CommandLineFu. . In the absence of a forum, I encourage people welcome him, here, in the comments. . Also... What would you like to improve/change about the site?

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

Sum columns from CSV column $COL
More of the same but with more elaborate perl-fu :-)


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