Commands by Coderjoe (1)

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

Bash scripts encryption and passphrase-protection
This function will encrypt a bash script and will only execute it after providing the passphrase. Requires mcrypt to be installed on the system. $ cat hello #!/bin/bash case "$1" in ""|-h) echo "This is the fantastic Hello World. Try this:" $(basename $0) "[entity]" ;; moon) echo Good night. ;; sun) echo Good morning. ;; world) echo "Hello, world!" ;; *) echo Hi, $@. ;; esac $ scrypt hello Enter the passphrase (maximum of 512 characters) Please use a combination of upper and lower case letters and numbers. Enter passphrase: Enter passphrase: Stdin was encrypted. $ cat hello.scrypt . <(echo "$(/usr/bin/tail -n+2 $0|base64 -d|mcrypt -dq)");exit; AG0DQHJpam5kYWVsLTEyOAAgAGNiYwBtY3J5cHQtc2hhMQAV34412aaE8sRzQPQzi09YaNQPedBz aGExAARvB6A/HYValW4txoCFmrlp57lmvhKBbM4p+OUiZcCxr6Y+Mm7ogg3Y14pHi0CrfT70Tubq 9g8/kNJrQr7W/ogHpVuOOdD0YfuRatrV7W2+OlNQ63KX780g4qTHrTqNnyLp8sF5RQ7GwxyZ0Oti kROtVIU4g4+QAtn/k/e7h7yt4404VF1zzCYRSw20wmJz1o/Z0XO7E/DFBr5Bau7bWjnF7CRVtims HGrDwv1miTtAcyB9PknymDxhSyjDUdNhqXGBIioUgqjX1CKgedtO0hQp050MiQd3I6HacpSrVUIW kuuS+BtMrxHDy+48Mh1hidV5JQFP7LP5k+yAVLpeHd2m2eIT1rjVE/Bp2cQVkpODzXcWQDUAswUd vulvj/kWDQ== $ ./hello This is the fantastic Hello World. Try this: hello [entity] $ ./hello.scrypt Enter passphrase: This is the fantastic Hello World. Try this: hello.scrypt [entity] $ ./hello world Hello, world! $ ./hello.scrypt world Enter passphrase: Hello, world!

Cut/Copy brackets or parentheses on vim (in normal mode)
We have for example : func () { echo FOO echo BAR } Place the cursor under a bracket and press d + %. It will cut everything inside and the brackets. It let : func () You can copy text with y + %

Quick directory bookmarks
Set a bookmark as normal shell variable $ p=/cumbersome/path/to/project To go there $ to p This saves one "$" and is faster to type ;-) The variable is still useful as such: $ vim $p/ will expand the variable (at least in bash) and show a list of files to edit. If setting the bookmarks is too much typing you could add another function $ bm() { eval $1=$(pwd); } then bookmark the current directory with $ bm p

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" }

Extracting frames from a video as jpeg files
This command extracts 10 seconds worth of frames, starting from 00:15:45 position, from filename.avi and stores them into out_frames folder as jpeg files. Subtitles are turned off with -sid 999 option.

command! -nargs=1 Vs vs <args>
Because entering ':' requires that you press shift, sometimes common command-line / mini-buffer commands will be capitalized by accident.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

run a VirtualBox virtual machine without a gui
you can launch a VirtualBox VM from the command line using VBoxManage, but that invokes it in a gui environment. If you want to just fire off your VM in the background, use VBoxHeadless as shown. To get the names and UUIDs of your VirtualBox VMs, type: $ VBoxManage list

Renaming a file without overwiting an existing file name
Sometimes in a hurry you may move or copy a file using an already existent file name. If you aliased the cp and mv command with the -i option you are prompted for a confirmation before overwriting but if your aliases aren't there you will loose the target file! The -b option will force the mv command to check if the destination file already exists and if it is already there a backup copy with an ending ~ is created.


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