Magp.ie » terminal

Uninstall and Remove Xcode Completely

Eoin — Mon, 12 Dec 2011 17:12:53 +0000

If you are in a position where you want to remove the colossus that is Xcode, here is the terminal command to use.

sudo /Developer/Library/uninstall-devtools –mode=all

In my case, I was using migration assistant to migrate my applications and user account to a new laptop. My older laptop had an older version of Xcode that I didn’t want included in the migration and as it is so big, I didn’t want to take the chance.

Kudos to Pushkararora.com

Filed under: Guides Tagged: bash, max osx, remove, terminal, uninstall, xcode

Find process using port number in Bash

Eoin — Tue, 19 Apr 2011 08:37:03 +0000

Something that has bugged me recently is that when I go to proxy on a particular port, the port is already in use and I get the following error.
bind: Address already in use channel_setup_fwd_listener: cannot listen to port: 8090 Could not request local forwarding.

So I had a quick look to find out how to locate the process hogging the port. All I need to do is use the lsof command.

lsof -i:8090

This command returns a list of open processes on this port.

Something like…
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME ssh 75782 eoin 5u IPv6 0x01c1c234 0t0 TCP localhost:8090 (LISTEN)

To free the port, kill the process using it…
kill 75782

[Update: Simpler solution found]

Easier to kill all ssh processes and restart them (if you use terminal aliases!), since in my case it is always an ssh process that is hogging the port.

killall ssh

Filed under: Guides Tagged: bash, killall, lsof command, terminal, Unix

Debugging PHP by monitoring errors in terminal

Eoin — Thu, 10 Mar 2011 20:27:00 +0000

This is a super simple command but there is something about the following sequence of characters that I simply cannot retain in my brain.

tail -f /tmp/php-errors

This is a handy command to debug your PHP on your server where you may have errors hidden.

The tail command shows the end of a file.
The -f flag tells it to keep the file open, while you debug your code
The /tmp/php-error is ( I assume! ) a temporary error log file that stores PHP errors on the server.

Update:

If you use error_log(print_r(debug_backtrace(), true )) with this command, you can monitor the call stack in real time. Super useful when debugging!

Filed under: Guides Tagged: bash, command, debugging techniques, debug_backtrace, error_log, php, terminal

Command Line Shortcuts

Eoin — Thu, 27 Jan 2011 09:44:04 +0000

Excellent post from one of my favourite sites – Become a command line ninja with these time saving shortcuts

Filed under: Shortcuts Tagged: commands, lifehacker, shortcuts, terminal

Using Terminal Screen Command

Eoin — Fri, 22 Oct 2010 21:09:43 +0000

This is a simple one. For some reason, every time I use the screen command in terminal, I forget the commands.

There are probably lots of cool reasons to use screen but I use it to run a script over a longish period. The advantage of screen is I can start the script in the screen instance and detach from it. I can close my laptop and return later to my terminal, open my screen and check the progress of the script. Also, you can run multiple instances of a script as each screen has its own process.

So the basic commands I use and tend to forget are…

Create a screen with a label so you know what it’s for: screen -S 'run-long-script1'

Detach from the screen: Ctrl + a + d

Kill the screen: exit

Check what screens you have created: screen -ls

Open a screen that you have already created: screen -r 'run-long-script1'

Access the extensive screen manual: man screen

Found this guide helpful from thegeekstuff.

Filed under: Guides Tagged: bash, commands, screen, terminal

Terminal Aliases

Eoin — Thu, 11 Feb 2010 12:28:16 +0000

Sick of typing out long commands, bad at typing, forget commands from time to time or all 3 like me… then aliases are here to help.

Basically, you can use a handy short memorable alias for a long and possible complicated one in terminal by doing the following.

Open terminal, go to root ( cd ~/ ) and see if a file under the name .bash_login exists… if not create it.

Open this file in vim, enter your aliases like so…
alias dev1=’ssh username@serverhostname.com’
alias dev2=’ssh username@anotherserverhostname.com’

So now each time I enter dev1 into the terminal, I will be ssh’ing into my server, or dev2 to ssh into another one without having to recall the hostname and such… sweet.

You can add as many as you like for any command.

HANDY TIP: Enter the alias !=history and now you each time you type ! plus some text, the terminal will figure out which command to call based on your terminal history and the text you entered.

HANDY TIP #2: Use CTRL+R to search through any of your previous commands, you can insert any part of the command… super!
Thanks Donncha

Filed under: Shortcuts Tagged: aliases, SSH, terminal