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Run a long job and notify me when it's finished
You will need libnotify-bin for this to work: $ sudo aptitude install libnotify-bin

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" }

Get your outgoing IP address

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"

Press a key automatically
Press a key automatically via xvkbd.

Fill up disk space (for testing)
Put into some file. No special purpouse, just for fun...

Convert embedded spaces in filenames to "_" (underscore)
This command converts filenames with embedded spaces in the current directory replacing spaces with the underscore ("_") character.

Check RAM size
Check RAM size

Create a bunch of dummy files for testing
Sometimes I need to create a directory of files to operate on to test out some commandlinefu I am cooking up. The main thing is the range ({1..N}) expansion.

The fastest remote directory rsync over ssh archival I can muster (40MB/s over 1gb NICs)
This creates an archive that does the following: rsync:: (Everyone seems to like -z, but it is much slower for me) -a: archive mode - rescursive, preserves owner, preserves permissions, preserves modification times, preserves group, copies symlinks as symlinks, preserves device files. -H: preserves hard-links -A: preserves ACLs -X: preserves extended attributes -x: don't cross file-system boundaries -v: increase verbosity --numeric-ds: don't map uid/gid values by user/group name --delete: delete extraneous files from dest dirs (differential clean-up during sync) --progress: show progress during transfer ssh:: -T: turn off pseudo-tty to decrease cpu load on destination. -c arcfour: use the weakest but fastest SSH encryption. Must specify "Ciphers arcfour" in sshd_config on destination. -o Compression=no: Turn off SSH compression. -x: turn off X forwarding if it is on by default. Flip: rsync -aHAXxv --numeric-ids --delete --progress -e "ssh -T -c arcfour -o Compression=no -x" [source_dir] [dest_host:/dest_dir]


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