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Check every URL redirect (HTTP status codes 301/302) with curl

Steve Reich - Piano Phase; interpreter: Bourne-Again Shell.
The Piano Phase piece, by Steve Reich is a minimalist composition which is played on two pianos played at slightly different tempos, a task that's very difficult to accomplish by human players. The auditive effects produced by the cell displacement produce beautiful patterns. See https://en.wikipedia.org/wiki/Piano_Phase . My rendered version: https://ydor.org/SteveReich/piano_phase.mp3 Requires sox to be installed on the system. There are multiple videos on youtube showing different approaches and experiences to this interpretation. There is also a synthesized version. Even if Bash can behave as a powerful pianist, a simple threaded version leaves full room to several time glitches and even negative displacements, the same issues that human pianists experience when playing the piece. The older the computer, the better the chaos added to the result due to the CPU load. Apparently that's the reason Steve Reich composes pieces such as this. Without further ado, please give a warm welcome to the Bash minimalist player on synthesized two-threaded pianos. Please turn off your cellphones.

Compute the average number of KB per file for each dir
Shorter version using --tag

connects to db2 database instance/alias "stgndv2" user "pmserver" using password "xxxxxxx"
db2 => ? connect CONNECT [USER username [{USING password [NEW new-password CONFIRM confirm-password] | CHANGE PASSWORD}]] CONNECT RESET CONNECT TO database-alias [IN {SHARE MODE | EXCLUSIVE MODE [ON SINGLE DBPARTITIONNUM]}] [USER username [{USING password [NEW new-password CONFIRM confirm-password] | CHANGE PASSWORD}]]

Network Proxy to dump the application level forward traffic in plain text in the console and in a file.
If you have a client that connects to a server via plain text protocol such as HTTP or FTP, with this command you can monitor the messages that the client sends to the server. Application level text stream will be dumped on the command line as well as saved in a file called proxy.txt. You have to change 8080 to the local port where you want your client to connect to. Change also 192.168.0.1 to the IP address of the destination server and 80 to the port of the destination server. Then simply point your client to localhost 8080 (or whatever you changed it to). The traffic will be redirected to host 192.168.0.1 on port 80 (or whatever you changed them to). Any requests from the client to the server will be dumped on the console as well as in the file "proxy.txt". Unfortunately the responses from the server will not be dumped.

Find last reboot time
Specific to OSX.

Url Encode
Converts reserved characters in a URI to their percent encoded counterparts. Alternate python version: $ echo "$url" | python -c 'import sys,urllib;print urllib.quote(sys.stdin.read().strip())'

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"

Runs previous command replacing foo by bar every time that foo appears
Very useful for rerunning a long command changing some arguments globally. As opposed to ^foo^bar, which only replaces the first occurrence of foo, this one changes every occurrence.

Get a stream feed from a Twitter user
*** CAREFULLY READ THE NOTES **** *** THIS DOES NOT WORK "OUT OF THE BOX" *** You'll need a few minutes of CAREFUL reading before making your own Twitter feed: In 2010 simple command line Twitter feed requests all stopped working because Twitter upgraded to SSL security. Https requests for a filtered Twitter stream feed now require a special header called "oauth_header". The benefit is that your stream feed and login info is securely encrypted. The bad news is that an "oauth_header" takes some work to build. Fortunately, four functions, imaginatively named step1, step2, step3 and step4 can be used to build a customized oauth_header for you in a few minutes. Now, go look at "step1" to start creating your own oauth_header!


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