Commands by jbcurtis (2)

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Backup a file with a date-time stamp
1. you don't need to prepend the year with 20 - just use Y instead of y 2. you may want to make your function a bit more secure: buf () { cp ${1?filename not specified}{,$(date +%Y%m%d_%H%M%S)}; }

Check a server is up. If it isn't mail me.
Joker wants an email if the Brand X server is down. Set a cron job for every 5 mins with this line and he gets an email when/if a ping takes longer than 3 seconds.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Summarize Apache Extended server-status to show longest running requests
Ever need to know why Apache is bogging down *right now*? Hate scanning Apache's Extended server-status for the longest running requests? Me, too. That's why I use this one liner to quickly find suspect web scripts that might need review. Assuming the Extended server-status is reachable at the target URL desired, this one-liner parses the output through elinks (rendering the HTML) and shows a list of active requests sorted by longest running request at the bottom of the list. I include the following fields (as noted in the header line): Seconds: How long the request is alive PID: Process ID of the request handler State: State of the request, limited to what I think are the relevant ones (GCRK_.) IP: Remote Host IP making the request Domain: Virtual Host target (HTTP/1.1 Host: header). Important for Virtual Hosting servers TYPE: HTTP verb URL: requested URL being served. Putting this in a script that runs when triggered by high load average can be quite revealing. Can also capture "forgotten" scripts being exploited such as "formmail.pl", etc.

dstat - a mix of vmstat, iostat, netstat, ps, sar...
This is a very powerful command line tool to gather statistics for a Linux system. http://dag.wieers.com/home-made/dstat/

Create tar over SSH
Really useful when out of space in your current machine. You can ran this also with cat for example: $ tar zcvf - /folder/ | ssh [email protected] "cat > /dest/folder/file.tar.gz" Or even run other command's: $ tcpdump | ssh [email protected] "cat > /tmp/tcpdump.log"

Output sound when your computer is downloading something
Outputs pseudo-random sounds to speakers (stereo mode because of -c 2) when there are any kind of network activity.

Force wrap all text to 80 columns in Vim
This is assuming that you're editing some file that has not been wrapped at 80 columns, and you want it to be wrapped. While in Vim, enter ex mode, and set the textwidth to 80 columns: $ :set textwidth=80 Then, press: $ gg to get to the top of the file, and: $ gqG to wrap every line from the top to the bottom of the file at 80 characters. Of course, this will lose any indentation blocks you've setup if typing up some source code, or doing type setting. You can make modifications to this command as needed, as 'gq' is the formatting command you want, then you could send the formatting to a specific line in the file, rather than to the end of the file. $ gq49G Will apply the format from your current cursor location to the 49th row. And so on.

ls not pattern
Hides some entries from listing.

network usage per process
Nethogs groups bandwidth by process.


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