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Backup with versioning
Apart from an exact copy of your recent contents, also keep all earlier versions of files and folders that were modified or deleted. Inspired by EVACopy http://evacopy.sourceforge.net

Create subversion undo point
Allows you to save progress without committing. To revert to an undo point, svn revert then apply the undo point with patch. $ svn revert -R . && patch -p0 < .undo/2009-03-27_08:08:11rev57 Similar: http://www.commandlinefu.com/commands/view/373/archive-all-files-containing-local-changes-svn

Convert every eps in a directory to pdf
Converts every *.eps file to a *.pdf file

Show this month's calendar, with today's date highlighted
Explanation: * The date command evaluated to today's date with blank padded on the left if single digit * The grep command search and highlight today's date * The --before-context and --after-context flags displays up to 6 lines before and after the line containing today's date; thus completes the calendar. I have tested this command on Mac OS X Leopard and Xubuntu 8.10

Rename files in batch

convert png into jpg using imagemagick

Move all images in a directory into a directory hierarchy based on year, month and day based on exif information
This command would move the file "dir/image.jpg" with a "DateTimeOriginal" of "2005:10:12 16:05:56" to "2005/10/12/image.jpg". This is a literal example from the exiftool man page, very useful for classifying photo's. The possibilities are endless.

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.

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"

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }


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