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Stat each file in a directory
Possible simplification of egrep-awk-sort with find and -exec with xargs.

Use AWS CLI and JQ to get a list of instances sorted by launch time
You can do the filtering natively in the aws cli, without using jq (although jq is awesome!)

Insert a line at the top of a text file without sed or awk or bash loops
Yet another way to add a line at the top a of text file with the help of the tac command (reverse cat).

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"

connect to all screen instances running
connects to all the screen instances running.

Use mtr to create a text file report
The report mode of mtr produces a text formated result of the mtr run using the number of ping cycles stated by the command. This text file could then be attached to an email with ease. I use this also without the ">" portion when writing email from within mutt using VI from the command mode with ":r !mtr --report --report-cycles 10 www.google.com" to actually input the same output in the body of an email.

PulseAudio: set the volume via command line
If you have more than one SINK

bash shortcut: !$ !^ !* !:3 !:h and !:t
When expanding, bash output the command, so don't be affraid if you type the command. Here is the details: First examples: $echo foo bar foobar barfoo First argument: $echo !$ echo barfoo barfoo (Note that typing echo foo bar foobar barfoo && echo !$, bash substitute !$ with $:1) Last argument: $echo foo bar foobar barfoo && echo !^ echo foo bar foobar barfoo && echo barfoo foo bar foobar barfoo barfoo All the arguments: $echo !* echo foo bar foobar barfoo foo bar foobar barfoo The third argument: $echo foo bar foobar barfoo && echo !:3 echo foo bar foobar barfoo && echo foobar foo bar foobar barfoo foobar You may want to add {} for large numbers: echo !:{11} for example Now with path: $echo /usr/bin/foobar /usr/bin/foobar For the head: $echo !$:h echo /usr/bin /usr/bin And the tail: $echo !$:t echo foobar foobar You also may want to try !:h and !:t or !!3-4 for the third and the fourth (so !!:* == !!:1-$)

list block devices
Shows all block devices in a tree with descruptions of what they are.

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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