Commands by podiiii (1)

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Convert JSON to YAML
Requires installing json2yaml via npm: npm install -g json2yaml (can also pipe from stdin) Ref: https://www.npmjs.com/package/json2yaml

Remove security limitations from PDF documents using ghostscript (for Windows)
#4345 also works under windows

Plaintext credentials sniffing with tcpdump and grep
Simple TCPDUMP grepping for common unsafe protocols (HTTP, POP3, SMTP, FTP)

Delete all files by extension
This is a correction to https://www.commandlinefu.com/commands/view/22134 Use `-name` instead of `-iname`, because case-sensitivity is probably important when we're dealing with filenames. It's true that extensions are often capitalised (e.g., "something.JPG"), so choose whatever's appropriate. However, what is appropriate is the quoting of the name pattern, so the shell doesn't expand it incorrectly. Finally, `-delete` is clearer.

List all PostgreSQL databases. Useful when doing backups

Stripping ^M at end of each line for files
That "^M" is Ctrl-M, which is a carriage return, and is not needed in Unix file systems. Where ^V is actually Ctrl-V and ^M is actually Ctrl-M (you must type these yourself, don't just copy and paste this command). ^V will not be displayed on your screen.

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" }

Burn a directory of mp3s to an audio cd.
This uses mpg123 to convert the files to wav before burning, but you can use mplayer or mencoder or ffmpeg or lame with the --decode option, or whatever you like.

search installed files of package, that doesn't remember his name well. On rpm systems
rpm, sometimes, is not wildcard friendly. To search files installed from package this could be useful. change PACKAGENAME to any package do you want to search

Set audible alarm when an IP address comes online
Waiting for your server to finish rebooting? Issue the command above and you will hear a beep when it comes online. The -i 60 flag tells ping to wait for 60 seconds between ping, putting less strain on your system. Vary it to your need. The -a flag tells ping to include an audible bell in the output when a package is received (that is, when your server comes online).

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