Commands by H4rpy

Commands by H4rpy (5)

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start vim in diff mode

vim will open both files side by side and show colored diffs Show Sample Output

vimdiff file{1,2}

H4rpy · 2009-03-23 10:08:16 6

Make backups recurse through directories
This is sample output - yours may be different.
2

find -type -f -exec cp {} {}.bak \;

H4rpy · 2009-03-02 16:51:34 6
Show every subdirectory (zsh)
This is sample output - yours may be different.
2

ls -ld **/*(/)

H4rpy · 2009-02-27 08:31:34 16
Show top-level subdirectories (zsh)
This is sample output - yours may be different.
0

ls -ld *(/)

H4rpy · 2009-02-27 08:30:16 5
opening your helper script without knowing the path (zsh)

This is equivalent to: less `which rcsyslog`
This is sample output - yours may be different.
0

less =rcsyslog

H4rpy · 2009-02-22 14:07:41 5

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find and reduce 8x parallel the size of PNG images without loosing quality via optipng

Set laptop display brightness

Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video). $ cat /proc/acpi/video/VGA/LCD/brightness to discover the possible values for your display.

Quickly find a count of how many times invalid users have attempted to access your system

Execute a command with a timeout

In this example the command "somecommand" will be executed and sent a SIGALARM signal if it runs for more than 10 seconds. It uses the perl alarm function. It's not 100% accurate on timing, but close enough. I found this really useful when executing scripts and commands that I knew might hang E.g. ones that connect to services that might not be running. Importantly this can be used within a sequential script. The command will not release control until either the command completes or the timeout is hit.

Copy a file with progress and save hash to a different file

Find the package that installed a command

Extract the MBR ID of a device

Useful when you want to know the mbrid of a device - for the purpose of making it bootable. Certain hybridiso distros, for eg the OpenSUSE live ISO uses the mbrid to find the live media. Use this command to find out the mbrid of your USB drive and then edit the /grub/mbrid file to match it.

a shell function to print a ruler the width of the terminal window.

Copy via tar pipe while preserving file permissions (run this command as root!)

It's the same like 'cp -p' if available. It's faster over networks than scp. If you have to copy gigs of data you could also use netcat and the tar -z option in conjunction -- on the receiving end do: # nc -l 7000 | tar -xzvpf - ...and on the sending end do: # tar -czf - * | nc otherhost 7000

list block devices

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

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