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scp with compression.
-C is for compression.

move a lot of files over ssh
copy files to a ssh server with gzip compression

Hostname tab-completion for ssh
This is meant for the bash shell. Put this function in your .profile and you'll be able to use tab-completion for sshing any host which is in your known_hosts file. This assumes that your known_hosts file is located at ~/.ssh/known_hosts. The "complete" command should go on a separate line as such: function autoCompleteHostname() { local hosts=($(awk '{print $1}' ~/.ssh/known_hosts | cut -d, -f1)); local cur=${COMP_WORDS[COMP_CWORD]}; COMPREPLY=($(compgen -W '${hosts[@]}' -- $cur )) } complete -F autoCompleteHostname ssh

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Search and Replace across multiple files
- grep for the word in a files, use recursion (to find files in sub directories), and list only file matches -| xargs passes the results from the grep command to sed -sed -i uses a regular expression (regex) to evaluate the change: s (search) / search word / target word / g (global replace)

Shell function to create a directory named with the current date, in the format YYYYMMDD.
Creates a directory named with the current date, in the format YYYYMMDD. If you give it a directory name as an argument, it will create the new directory inside the specified directory. This is an alternative to command #1993.

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" }

Close specify detached screen
-X Send the specified command to a running screen session. -S Option to specify the screen session if you have several screen sessions running. $screen -ls for listing current screens and its sessionname

Decode base64-encoded file in one line of Perl
If you are in an environment where you don't have the base64 executable or MIME tools available, this can be very handy for salvaging email attachments when the headers are mangled but the encoded document itself is intact.

one-liner mpc track changer using dmenu
Add a [fluxbox] binding in your key file then this command provides a dmenu selector for the next track to play


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