Commands by toddjcastillo (0)

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Copy ssh keys to user@host to enable password-less ssh logins.
Alternative for machines without ssh-copy-id

identify exported sonames in a path
This provides a list of shared object names (sonames) that are exported by a given tree. This is usually useful to make sure that a given required dependency (NEEDED entry) is present in a firmware image tree. The shorter (usable) version for it would be $ scanelf -RBSq -F "+S#f" But I used the verbose parameters in the command above, for explanation.

Re-use the previous command output
The $(!!) will expand to the previous command output (by re-running the command), which becomes the parameter of the new command newcommand.

Spy audio, it only records if detects a sound or noise
It find out the mic recording level at the moment of run the command and if a noise level is higher it starts to record an mp3 file. The resulting file will have only the sounds not the silences.

Rsync files with spaces
Using the double dash before the source and target makes the command work fine with weird filenames.

restore the contents of a deleted file for which a descriptor is still available
Note that the file at the given path will have the contents of the (still) deleted file, but it is a new file with a new node number; in other words, this restores the data, but it does not actually "undelete" the old file. I posted a function declaration encapsulating this functionality to http://www.reddit.com/r/programming/comments/7yx6f/how_to_undelete_any_open_deleted_file_in_linux/c07sqwe (please excuse the crap formatting).

list offsets from HEAD with git log.

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"

Have your sound card call out elapsed time.
Useful contexts : You are doing yoga or some other physical training in which you are holding a position. Or you practice the pomodoro productivity technique. Or your girlfriend said "We're leaving in 40 minutes". Design details: sleep executes before espeak to give you a 5 seconds head start. espeak is run in the background so it doesn't mess up the timing.

Assign top-level JSON entries to shell variables
A recursive version might be useful too. /dev/tty is used to show which shell variables just got defined.

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