Commands using echo (1,545)

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geoip information
That makes a function you can put in your ~/.bashrc to run it when you need in any term with an IP as argument

Add existing user to a group

Emulating netcat -e (netcat-traditional or netcat-openbsd) with the gnu-netcat
Then just nc servername 2600 and ./script.sh kill the client with ctrl+c. You can reconnect several times. kill the server with exit

Monitor cpu in realtime.

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" }

Realtime lines per second in a log file
Displays the realtime line output rate of a logfile. -l tels pv to count lines -i to refresh every 10 seconds -l option is not in old versions of pv. If the remote system has an old pv version: ssh tail -f /var/log/apache2/access.log | pv -l -i10 -r >/dev/null

Shows a specific process memory usage

Clone or rescue a block device
If you use the logfile feature of ddrescue, the data is rescued very efficiently (only the needed blocks are read). Also you can interrupt the rescue at any time and resume it later at the same point. http://www.gnu.org/software/ddrescue/ddrescue.html

get absolute file path
Retrieve absolute path name from relative path

List all symbolic links in current directory
For those who don't have the symlinks command, you can use readlink. This command is not straightforward because readlink is very picky. The backslash in front of 'ls' means not to use an alias (e.g. color escape codes from an aliased 'ls' could mess up readlink), and the -1 (one) means to print the entries separated by newlines. xargs -l (the letter L) means to process each input separated by newlines as separate commands.


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