Commands by kaedenn

Commands by kaedenn (5)

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Quickly re-execute a recent command in bash

! will expand to the last time you ran , options and all. It's a nicer alternative to ^R for simple cases, and it's quite helpful for those long commands you run every now and then and haven't made aliases or functions for. It's similar to command 3966, in some sense. Show Sample Output
This is sample output - yours may be different.
```
$ mysql --sigint-ignore --host <host> --user <user> --password --database <db> -e 'select * from contacts' > contacts.tab
# several lines later, database has been updated, need to re-download the table
$ !mysql
mysql --sigint-ignore --host <host> --user <user> --password --database <db> -e 'select * from contacts' > contacts.tab
```
1

!<command>

kaedenn · 2011-08-16 18:37:18 6
Backup a file before editing it.

Some people put spaces in filenames. Others have an $EDITOR environment variable set. This defaults to vim, but you can use whatever you wish: emacs, nano, ed, butterflies, etc.
This is sample output - yours may be different.
-6

sedit() { cp "$*"{,.bk}; which $EDITOR > /dev/null && $EDITOR "$*" || vim "$*"; }

kaedenn · 2011-08-16 18:28:22 5
Revert an SVN file to previous revision

Kudos to xakon.
This is sample output - yours may be different.
2

svn up -rREV file

kaedenn · 2011-03-29 10:57:39 5
delete all leading and trailing whitespace from each line in file

Sometimes those files have more than just spaces and tabs around them. Plus, this is just a little shorter.
This is sample output - yours may be different.
0

sed 's/^\s*//;s/\s*$//' -i file

kaedenn · 2010-08-24 05:03:48 7
Leap year calculation

Tested on bash, and follows all the rules about leap years. Show Sample Output
This is sample output - yours may be different.
```
$ leapyear 2000
2000 is a leap year!
$ leapyear 2400
2400 is a leap year!
$ leapyear 2600
2600 is not a leap year.
```
-2

leapyear() { if [ $[$1 % 4] -eq 0 ] && [ $[$1 % 100] -ne 0 ] || [ $[$1 % 400] -eq 0 ]; then echo $1' is a leap year!'; else echo $1' is not a leap year.'; fi; }

kaedenn · 2010-03-30 17:19:20 5

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Combine multiple images into a video using ffmpeg

The -start_number can be ignored if sequence starts with 0, otherwise use first number in sequence

FInd the 10 biggest files taking up disk space

Get sunrise and sunset times

This will get the sunrise and sunset times of a specific location. To be able to determine $l you need to first go to http://weather.yahoo.com/ and look up your location. The last numbers in the URL will be the $l Instead of forecastrss?w=$l you can also use forecastrss?p=$l and use the RSS link of the city you found. Also see http://developer.yahoo.com/weather/ for more information

Convert current symbolic directory into physical directory

Generate random valid mac addresses

Ruby version. Also, a perl version: $perl -e 'printf("%.2x.",rand(255))for(1..5);printf("%.2x\n",rand(255))'

Show apps that use internet connection at the moment. (Multi-Language)

enable all bash completions in gentoo

enable each bash completion that you have installed at your system, that's very nice ;)

Detect illegal access to kernel space, potentially useful for Meltdown detection

Based on capsule8 agent examples, not rigorously tested

Search back through previous commands

Searches backwards through your command-history for the typed text. Repeatedly hitting Ctrl-R will search progressively further. Return invokes the command.

burn initial session on a growable DVD using growisofs

replace "directory name to burn on DVD" with actual directory name that you want to copy on DVD

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