the place for useful commands, 1-liners, mini-howtos & snippets

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create tar.gz archiv

 tar -czvf myfiles.tar.gz /home/username/myfiles/

backup mirror.tar via ssh & cat

the file-globbing regex /[a-oq-z]* leaves out /p* dirs, to exclude /proc

 ssh -v root@hostname tar cvf - /[a-oq-z]* | cat > /backupdir/mirror.tar

create and use a swapfile

 dd if=/dev/zero of=/swapfile bs=1024 count=100000
 mkswap /swapfile
 

edit /etc/fstab – add a swap-line for auto activation after reboot:

 /swapfile       swap    swap    defaults        0       0

turn it on:

 swapon /swapfile

and verify:

 free -m
 mount

mp3 “normalize” by id3 tag

mp3gain analyses sound files and saves an id3 volume metatag to them. many music-players can read that id3 tag and adjust the volume to that gain.

 find /path/to/music/ -type f -iname '*.mp3' -print0 | xargs -0 mp3gain -r -k