Commands tagged math (13)

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List bash functions defined in .bash_profile or .bashrc
http://stackoverflow.com/questions/2625783/listing-defined-functions-in-bash#2627461

Suspend, background, and foreground a process
1. Start a process, such as 'top' command 2. # suspend process {ctrl-Z} 3. # background process bg 4. # list all backgrounded jobs jobs 5. # bring it back to foreground fg

Perform sed substitution on all but the last line of input
In this simple example the command will add a comma to the end of every line except the last. I found this really useful when programatically constructing sql scripts. See sample output for example.

Download all videos in your Boxee queue
Gets all videos in your boxee queue with a URL associated with them and attempts to download each using get_flash_videos

Plays Music from SomaFM
This command asks for the station name and then connects to somafm, Great for those who have linux home entertainment boxes and ssh enabled on them, just for the CLI fiends out there ( I know I'm one of them ;) Also, don't forget to add this as alias(ie alias somafm="read -p 'Which Station? "; mplayer --reallyquite -vo none -ao sdl http://somafm.com/startstream=${REPLY}.pls")

convert unixtime to human-readable with awk
- convert unixtime to human-readable with awk - useful to read logfiles with unix-timestamps, f.e. squid-log: sudo tail -f /var/log/squid3/access.log | awk '{ print strftime("%c ", $1) $0; }

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

The NMAP command you can use scan for the Conficker virus on your LAN
This was posted on reddit. replace 192.168.0.1-256 with the IP's you want to check.

How to backup hard disk timely?
'data' is the directory to backup, 'backup' is directory to store snapshots. Backup files on a regular basis using hard links. Very efficient, quick. Backup data is directly available. Same as explained here : http://blog.interlinked.org/tutorials/rsync_time_machine.html in one line. Using du to check the size of your backups, the first backup counts for all the space, and other backups only files that have changed.

Use /dev/full to test language I/O-failsafety
The Linux /dev/full file simulates a "disk full" condition, and can be used to verify how a program handles this situation. In particular, several programming language implementations do not print error diagnostics (nor exit with error status) when I/O errors like this occur, unless the programmer has taken additional steps. That is, simple code in these languages does not fail safely. In addition to Perl, C, C++, Tcl, and Lua (for some functions) also appear not to fail safely.


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