commandlinefu.com is the place to record those command-line gems that you return to again and again.
Delete that bloated snippets file you've been using and share your personal repository with the world. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.
If you have a new feature suggestion or find a bug, please get in touch via http://commandlinefu.uservoice.com/
You can sign-in using OpenID credentials, or register a traditional username and password.
First-time OpenID users will be automatically assigned a username which can be changed after signing in.
Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.
Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):
Subscribe to the feed for:
The command uses ssh(1) to get to a remote host, uses tar(1) to archive a remote directory, prints the result to STDOUT, which is piped to gzip(1) to compress to a local file. In other words, we are archiving and compressing a remote directory to our local box.
If you work in an environment, where some ssh hosts change regularly this might be handy...
This command shows a sorted list of the IP addresses from which there have been authentication errors via SSH (possible script kiddies trying to gain access to your server), it eliminates duplicates so it's easier to read, but you can remove the "uniq" command at the end, or even do a "uniq -c" to have a count of how many times each IP address shows in the log (the path to the log may vary from system to system)
Transfer files with rsync over ssh on a non-standard port, showing a progress bar and resuming partial transfers.
this way you have the multitail with all its options running on your own machine with the tails of the two remote machines inside :)
Listens on local port 5500 and connects to remotehost with username user to tunnel the given socket file. Will work with anything, but can be useful if there's a need for a local application to connect with a remote server which was started without networking.
Creates the .ssh directory on the remote host with proper permissions, if it doesnt exist. Appends your public key to authorized_keys, and verifies it has proper permissions. (if it didnt exist it may have been created with undesireable permissions).
*Korn shell syntax, may or may not work with bash
This one is a bit more robust -- the remote machine may not have an .ssh directory, and it may not have an authorized_keys file, but if it does already, and you want to replace your ssh public key for some reason, this will work in that case as well, without duplicating the entry.
analyze traffic remotely over ssh w/ wireshark
When using tcpdump, specify -U option to prevent buffering and -iany to see all interfaces.
Create a secure tunnelled connection for access to a remote MySQL database.
For example, connect with MySQL Workbench to firstname.lastname@example.org:13306.
Neat idea! This variation works on FreeBSD.
Shorter, easier to remember version of cmd#7636
NTP is better, but there are situations where it can't be used. In those cases, you can do this to sync the local time to a server.
If you have a lot of hosts in /etc/hosts this would be very useful. Anyone have any more concise examples?
SSH can be controlled trough an ~ escape sequence. Example, to terminate the current ssh connection, type a newline, then the ~ character, and last a . character.
This is useful eg when an ssh connection hangs after you reboot a machine and the connection hangs.
If you need to xdebug a remote php application, which is behind a firewall, and you have an ssh daemon running on that machine. you can redirect port 9000 on that machine over to your local machine from which you run your xdebug client (I am using phpStorm)
So, run this command on your local machine and start your local xdebug client, to start debugging.
Booting the VM headless via VBoxHeadless requires knowledge of the VM's network in order to connect. Using VBoxManage in this way and you can SSH to the VM without first looking up the current IP, which changes depending on how you have your VM configured.
This uses ssh to transfer the contents of one Mac's clipboard to another's. This only works with plain text, sadly. Trying to transfer images will just clear out the remote machine's clipboard, and rich text will be converted to plain text. Using the "Remote Login" must be enabled on the remote machine (via System Preferences' Sharing panel) for this to work.
This version compresses the data for transport.
In the example above 3 tables are copied. You can change the number of tables. You should be able to come up with variants of the command by modifying the mysqldump part easily, to copy some part of remote mysql DB.
This may be listed already but this command is useful to untar a specific directory to a different server.