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Create passwords and store safely with gpg
Adjust the $ head -c part for password length. I use filenames like "hans@commandlinefu.com.gpg" and a vim which automatically decrypts files with .gpg suffixes.

Generate a random password 30 characters long

Copy via tar pipe while preserving file permissions (run this command as root!)
It's the same like 'cp -p' if available. It's faster over networks than scp. If you have to copy gigs of data you could also use netcat and the tar -z option in conjunction -- on the receiving end do: # nc -l 7000 | tar -xzvpf - ...and on the sending end do: # tar -czf - * | nc otherhost 7000

copy timestamps of files from one location to another - useful when file contents are already synced but timestamps are wrong.
Sometimes when copying files from one place to another, the timestamps get lost. Maybe you forgot to add a flag to preserve timestamps in your copy command. You're sure the files are exactly the same in both locations, but the timestamps of the files in the new home are wrong and you need them to match the source. Using this command, you will get a shell script (/tmp/retime.sh) than you can move to the new location and just execute - it will change the timestamps on all the files and directories to their previous values. Make sure you're in the right directory when you launch it, otherwise all the touch commands will create new zero-length files with those names. Since find's output includes "." it will also change the timestamp of the current directory. Ideally rsync would be the way to handle this - since it only sends changes by default, there would be relatively little network traffic resulting. But rsync has to read the entire file contents on both sides to be sure no bytes have changed, potentially causing a huge amount of local disk I/O on each side. This could be a problem if your files are large. My approach avoids all the comparison I/O. I've seen comments that rsync with the "--size-only" and "--times" options should do this also, but it didn't seem to do what I wanted in my test. With my approach you can review/edit the output commands before running them, so you can tell exactly what will happen. The "tee" command both displays the output on the screen for your review, AND saves it to the file /tmp/retime.sh. Credit: got this idea from Stone's answer at http://serverfault.com/questions/344731/rsync-copying-over-timestamps-only?rq=1, and combined it into one line.

print first n characters of any file in human readble form using hexdump
Usefull to determine unknown file type

Stream YouTube URL directly to mplayer.

Get a diff of two json arrays
jq is amazing for manipulating json on the commandline, but the developers have some weird ideas about how to handle shell redirections. This command works around them. Further reading: https://github.com/stedolan/jq/issues/1110

Google Translate
$ translate [output-language] [source-language] 1) "some phrase" should be in quotes 2) [output-language] - optional (default: English) 3) [source-language] - optional (default: auto) $ translate "bonjour petit lapin" hello little rabbit $ translate "bonjour petit lapin" en hello little rabbit $ translate "bonjour petit lapin" en fr hello little rabbit

Search commandlinefu and view syntax-highlighted results in vim
Here is the full function (got trunctated), which is much better and works for multiple queries. function cmdfu () { local t=~/cmdfu; until [[ -z $1 ]]; do echo -e "\n# $1 {{{1" >> $t; curl -s "commandlinefu.com/commands/matching/$1/`echo -n $1|base64`/plaintext" | sed '1,2d;s/^#.*/& {{{2/g' | tee -a $t > $t.c; sed -i "s/^# $1 {/# $1 - `grep -c '^#' $t.c` {/" $t; shift; done; vim -u /dev/null -c "set ft=sh fdm=marker fdl=1 noswf" -M $t; rm $t $t.c } Searches commandlinefu for single/multiple queries and displays syntax-highlighted, folded, and numbered results in vim.

Make a playlistfile for mpg321 or other CLI player
A short variant if you have only one directory whit only audio files in it.


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