Commands by weldabar (2)

What's this? is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

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Check a server is up. If it isn't mail me.
This version uses netcat to check a particular service.

Creating A Single Image Video With Audio via ffmpeg

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

back ssh from firewalled hosts
host B (you) redirects a modem port (62220) to his local ssh. host A is a remote machine (the ones that issues the ssh cmd). once connected port 5497 is in listening mode on host B. host B just do a ssh -p 5497 -l user and reaches the remote host'ssh. This can be used also for vnc and so on.

peak amount of memory occupied by any process with "FOO" in its name
Show the maximum amount of memory that was needed by a process at any time. My use case: Having a long-running computation job on $BIG_COMPUTER and judging whether it will also run on $SMALL_COMPUTER. VmHWM: Peak resident set size ("high water mark")

Run a bash script in debug mode, show output and save it on a file

Speed up launch of firefox
Compress information DBs of firefox to speed up the launch of browser.

count files by type
displays a list of all file extensions in current directory and how many files there are of each type of extension in ascending order (case insensitive)

shell function to underline a given string.
underline() will print $1, followed by a series of '=' characters the width of $1. An optional second argument can be used to replace '=' with a given character. This function is useful for breaking lots of data emitted in a for loop into sections which are easier to parse visually. Let's say that 'xxxx' is a very common pattern occurring in a group of CSV files. You could run $ grep xxxx *.csv This would print the name of each csv file before each matching line, but the output would be hard to parse visually. $ for i in *.csv; do printf "\n"; underline $i; grep "xxxx" $i; done Will break the output into sections separated by the name of the file, underlined.

Resize photos without changing exif
To resize photos without changing exif datas, pretty cool for gps tagging. (Require ImageMagick)

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