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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Display duplicated lines in a file

Displays the duplicated lines in a file and their occuring frequency.

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"

Sort files by date

Show you the list of files of current directory sorted by date youngest to oldest, remove the 'r' if you want it in the otherway.

Length of longest line of code

Here's an awk version.

Remove a file whose name begins with a dash ( - ) character

Using the redundant ./ directory information prevents the dash from occurring at the beginning of the filename, and being interpreted as an option of the rm command. Also works using: $ rm -- -filename

Use a var with more text only if it exists

See "Parameter Expansion" in the bash manpage. They refer to this as "Use Alternate Value", but we're including the var in the at alternative.

Pretty-print user/group info for a given user

Get absolut path to your bash-script

Another way of doing it that's a bit clearer. I'm a fan of readable code.

show git logging

shows some logging for the git repo.

Revert an SVN file to previous revision

M - current revision, N - older revision

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