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 8
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 7

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delete file name space

delete file name space the rename is rename perl version

Sync the date of one server to that of another.

(Useful when firewalls prevent you from using NTP.)

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"

Show apps that use internet connection at the moment.

show only the name of the apps that are using internet

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" }

prevents replace an existing file by mistake

Use set +o noclobber and you will be able to replace files again

Top 10 Memory Processes

It displays the top 10 processes sorted by memory usage

Filter out all blank or commented (starting with #) lines

Display or use a random file from current directory via a small bash one-liner

An other way to run it ( playing a random file ending with avi, flv or mpeg ) from a specified dir and a specified type of extension : making MOVIE array with a glob : $ MOVIE=( /PATH/TO/MY/FAVORITE/MOVIES/*.{avi,flv,mpeg} ) playing the random file from a random key from the array $ mplayer ${MOVIE[ RANDOM % ( ${#i[@]} + 1 ) ]]} I use only globs and a bash array. I use GNU bash, version 3.2.48

list block devices

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

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