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validate json
I have this saved as jsonlint chmodded +x and file.js is instead $1, but YMMV

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" }

Calculate days on which Friday the 13th occurs (inspired from the work of the user justsomeguy)
Friday is the 5th day of the week, monday is the 1st. Output may be affected by locale.

encode HTML entities
Encodes HTML entities from input (file or stdin) so it's possible to directly past the result to a blog or HTML source file.

LDAP search to query an ActiveDirectory server
These are the parameters to ldapsearch (from ldap-utils in Ubuntu), for searching for the record for Joe Blogg's user. sAMAccountName is the LDAP field that ActiveDirectory uses to store the user name. 'DOMAIN\Joe.Bloggs' where "DOMAIN" is the the active directory domain. Othewise you could use "CN=Joe.Bloggs,DC=example,DC=com" instead of "DOMAIN\Joe.Bloggs"

recurisvely md5 all files in a tree
Found this little gem here: http://info.michael-simons.eu/2008/10/25/recursively-md5sum-all-files-in-a-directory-tree/

copy working directory and compress it on-the-fly while showing progress
What happens here is we tell tar to create "-c" an archive of all files in current dir "." (recursively) and output the data to stdout "-f -". Next we specify the size "-s" to pv of all files in current dir. The "du -sb . | awk ?{print $1}?" returns number of bytes in current dir, and it gets fed as "-s" parameter to pv. Next we gzip the whole content and output the result to out.tgz file. This way "pv" knows how much data is still left to be processed and shows us that it will take yet another 4 mins 49 secs to finish. Credit: Peteris Krumins http://www.catonmat.net/blog/unix-utilities-pipe-viewer/

Create an ISO Image from a folder and burn it to CD
Create an ISO Image from a folder and burn it to CD (Os X)

Take screenshot through SSH
When connected to a box via ssh you can do a quick screenshot of that box using this command. After that you can rscp it over to your box and look at it.

Backup all MySQL Databases to individual files
No need to loop when we have `xargs`. The sed command filters out the first line of `show databases` output, which is always "Database".


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