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Check your bash shell for vulnerability to the ShellShock exploit
If this command prints 'x' then your shell is vulnerable. Null output confirms that you are protected. Further reading: http://allanmcrae.com/2014/09/shellshock-and-arch-linux/

Create a new file

concatenate compressed and uncompressed logs
I use zgrep because it also parses non gzip files. With ls -tr, we parse logs in time order. Greping the empty string just concatenates all logs, but you can also grep an IP, an URL...

Print all open regular files sorted by the number of file handles open to each.
List all open files of all processes. . $ find /proc/*/fd Look through the /proc file descriptors . $ -xtype f list only symlinks to file . $ -printf "%l\n" print the symlink target . $ grep -P '^/(?!dev|proc|sys)' ignore files from /dev /proc or /sys . $ sort | uniq -c | sort -n count the results . Many processes will create and immediately delete temporary files. These can the filtered out by adding: $ ... | grep -v " (deleted)$" | ...

Upgrade all expired homebrew packages
You probably want to run `brew update` before you run this command

Update a namecheap @ A record to point to your current internet-facing IP address
Sets the @ A record for your domain hosted by namecheap to your current internet-facing IP address, logs success or failure with syslog, and logs the data returned to /root/dnsupdate. Change the XXX's as appropriate. More info at: http://www.namecheap.com/support/knowledgebase/article.aspx/29/

Merge several pdf files into a single file

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"

Burn an ISO on commandline with wodim instead cdrecord

Make changes in .bashrc immediately available
Any changes to BASH shell made in .bashrc will be active in the current terminal window from the moment you execute this command, ie. aliases, prompt settings etc. No need to restart terminal. (In BASH 'source' simile to 'eval' lets you generally execute any bunch of commands stacked in a text file).


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