Commands by maxmanders (5)

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generate a unique and secure password for every website that you login to
usage: sitepass MaStErPaSsWoRd example.com description: An admittedly excessive amount of hashing, but this will give you a pretty secure password, It also eliminates repeated characters and deletes itself from your command history. tr '!-~' 'P-~!-O' # this bit is rot47, kinda like rot13 but more nerdy rev # this avoids the first few bytes of gzip payload, and the magic bytes.

Restrict the use of dmesg for current user/session
Linux offers an interesting option to restrict the use of dmesg. It is available via /proc/sys/kernel/dmesg_restrict. You can check the status with: $ cat /proc/sys/kernel/dmesg_restrict Alternatively you can use sysctl: $ sudo sysctl -w kernel.dmesg_restrict=1 To make your change persistent across reboot, edit a fille in /etc/sysctl.d/.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Open up a man page as PDF (#OSX)
Simply pass an argument to the script to convert the manual page to a PDF: $man2pdf drutil

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" }

Setup a persistant SSH tunnel w/ pre-shared key authentication
This creates a persistent ssh -i /path/to/key -ND local-IP:PORT User@Server connection. You may have to install autossh. -f puts in daemon mode. if you are having trouble, try it without -f.

move you up one directory quickly
In bash, this turns on auto cd. If a command is just a directory name, it cd's into that directory.

Execute a command on multiple hosts in parallel
Ssh to host1, host2, and host3, executing on each host and saving the output in {host}.log. I don't have the 'parallel' command installed, otherwise it sounds interesting and less cryptic.

Recompress all text files in a subdirectory with lzma
This will deal nicely with filenames containing newlines and will run one lzma process per CPU core. It requires GNU Parallel http://www.youtube.com/watch?v=OpaiGYxkSuQ

Use AWS CLI and JQ to get a list of instances sorted by launch time
You can do the filtering natively in the aws cli, without using jq (although jq is awesome!)


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