Commands by karel1980

Commands by karel1980 (4)

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Generat a Random MAC address

Just increase the 1 at the end if you want to generate more than one. (Alternative to "| head -n N" you could use the -b flag of od: -b $[6*N] Show Sample Output
This is sample output - yours may be different.
```
ca:41:5d:28:ad:a2
```
2

od /dev/urandom -w6 -tx1 -An|sed -e 's/ //' -e 's/ /:/g'|head -n 1

karel1980 · 2011-05-16 15:05:34 1
Delete all but the latest 5 files, ignoring directories
This is sample output - yours may be different.
1

ls -lt|grep ^-|awk 'NR>5 { print $8 }'|xargs -r rm

karel1980 · 2009-09-16 07:43:03 0
Merge ( directories [looking for improvement]

Using a GUI file managers you can merge directories (cut and paste). This command roughly does the same (it doesn't ask for confirmation (no problem for me) and it doesn't clean up the empty SRC directories (no problem, trivial). probably does the same: cp -l SRC TARGET; rm -rf SRC
This is sample output - yours may be different.
0

(cd SRC; find . -type d -exec mkdir TARGET/{} ";"; find . -type f -exec mv {} TARGET/{} ";")

karel1980 · 2009-08-17 12:35:48 4
Move all images in a directory into a directory hierarchy based on year, month and day based on exif information

This command would move the file "dir/image.jpg" with a "DateTimeOriginal" of "2005:10:12 16:05:56" to "2005/10/12/image.jpg". This is a literal example from the exiftool man page, very useful for classifying photo's. The possibilities are endless. Show Sample Output
This is sample output - yours may be different.
```
    1 directories scanned
    1 directories created
  222 image files updated
    1 image files unchanged
```
15

exiftool '-Directory<DateTimeOriginal' -d %Y/%m/%d dir

karel1980 · 2009-08-04 11:47:34 4

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Waste time for about 3 minutes

If you're a slow reader and/or you like to ponder, adjust the sleep time to be longer

Stop long commands wrapping around and over-writing itself in the Bash shell

add the command either in /etc/profile or ~/.bash_profile so that this is available to your shell.

Ctrl+S Ctrl+Q terminal output lock and unlock

These are simple shortcuts to pause and continue terminal output, works in most terminals and screen multiplexers like screen. You can use it to catch something if things change too fast, and scroll with Shift + PgUp PgDown. On linux console ScrollLock can also be used.

Backup a directory structure

Copies a directory structure from /home/ to /backups/home (notice that the destination does not have a trailing slash)

Testing hard disk reading speed

Remove security limitations from PDF documents using ghostscript (for Windows)

#4345 also works under windows

Insert a line at the top of a text file without sed or awk or bash loops

Just use '-' to use STDIN as an additional input to 'cat'

list process ids for given program

list block devices

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

git diff of files that have been staged ie 'git add'ed

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