How to Copy Terminal Session into a File

admin    Linux     cat, command, copy, file, how-to, Linux, mkfifo, output, PinoyTux, redhat, script, session, software, terminal, text, tip, Tips, ubuntu, unix

Have you ever wondered how to copy the output of your terminal into a text file? Or maybe you teach Linux and you want to see what your students typed in and as well as the output? You think that running history is not enough? Then you need the script command.

Running script command

Open the man page of script command and you will see this:

Script makes a typescript of everything printed on your terminal. It is useful for students who need a hardcopy record of an interactive session as proof of an assignment, as the typescript file can be printed out later with lpr(1).

In a nutshell, it is history and tee all rolled into one. It will record everything you see on your screen, even the color. So if you typed in an invalid command, you will see the error in the log or if you run it correctly, you will have the output. But commands like top that refreshes the screen at an interval will most likely ruin the session or the log, so try to avoid similar commands.

To use it, just type the command script and it will begin recording the session. Once you are done, just type exit.

This is script in action:

rai@host1:~> script -a /tmp/script_test.log

Script started, file is /tmp/script_test.log
rai@host1:~> ls /home
R20 r200 R21 rai xx19
rai@host:~> thisnotacommandbutirunitanyway
bash: thisnotacommandbutirunitanyway: command not found
rai@host1:~> exit
Script done, file is /tmp/script_test.log
rai@host1:~> cat /tmp/script_test.log
Script started on Mon 17 Jan 2011 06:24:12 PM PHT
rai@lhost1:~> ls /home
R20 r200 R21 rai xx19
rai@host1:~> thisnotacommandbutirunitanyway
bash: thisnotacommandbutirunitanyway: command not found
rai@host1:~> exit

Script done on Mon 17 Jan 2011 06:24:54 PM PHT

The example above shows that script was started with -a option meaning it will append the output the specified file.

A better way to do this is to use it together with mkfifo command:

On Terminal 1 (Student’s terminal):

rai@host1:~> mkfifo /tmp/script_test.fifo
rai@host1:~> script -f /tmp/script_test.fifo

On Terminal 2 (Teacher’s terminal, same machine):

rai@host1:/tmp> cat /tmp/script_test.fifo

The above scenario will perform the following:
1) On the Student’s terminal, it will create an named pipe /tmp/script_test.fifo (man mkfifo) then run the script command with the -f option that ‘flushes’ out the output after each run. The Student’s terminal will look like it is not responding at this point, but don’t worry, it is perfectly normal.
2) On the Teacher’s terminal, the command cat will read the output file. Once you run the cat command, the session will be started.

Try the above steps and see how each screen behaves. Check also if doing the script command will create a populated output file.

How To Reset MySQL Password

Rai    Linux     change, how-to, Linux, login, mysql, new, password, reset, tip

If you are like me who tend to forget passwords almost every time, then this tip might help you reset your MySQL password just in case.

To begin, you must have access to the server, one that can stop and start the MySQL process, such as a root account. Sudo account can also be used, just as long that the user can control the MySQL service.

Begin the process by stopping the MySQL process. This can be done by executing /etc/init.d/mysqld stop command, but this can vary depending on how you setup your server. Also, be careful of users who might be using the MySQL service as stopping the service might disrupt their work.

Once the MySQL process is killed, execute the following command:

mysqld-safe --skip-grant-tables

This will run the MySQL process so you need to open another terminal to be able to reset the password. On the new terminal, you will now be able to login to MySQL to reset the password.

On the shell prompt of the new terminal, open the MySQL console:

mysql

mysql> use mysql;
mysql> UPDATE user SET Password=PASSWORD(‘YOUR_NEW_PASSWORD’) WHERE Host=’localhost’ AND User=’root’;
mysql> exit

This will change the password for the user ‘root’. Kill the MySQL process running in the first terminal, either by killing the PID or executing CTRL+C. Then start the process again, this time with the proper procedure:

/etc/init.d/mysqld start

Try logging in to the MySQL console using the new password:

mysql –uroot -p

You should now be able to use the new password for your MySQL.

Basic Apache and PHP Install from Source Part 1

Rai    How-To's, LAMP, Linux, Tips     apache, compile, configure, how-to, install, php, source, tarball

Ok, I may not be a guru when it comes to installing and configuring Apache and PHP but here is a sample of how I install Apache and PHP on Fedora or Red Hat boxes fresh from source. Pardon my newbie-sh technique but here it goes:

Installing Apache:

# cd /usr/src

- Download the http package

# wget http://www.apache.org/dist/httpd/httpd-2.2.8.tar.gz (change this to a mirror available to you)

- Extract the contents of the package

# tar zxf httpd-2.2.8.tar.gz

# cd httpd-2.2.8

- Configure the source depending on your requirements. At this point, configure may fail because of unsatisfied dependencies. Check what the error is and you can download the required package using yum or up2date. If you do not need SSL module for secure page (https), you can leave out the –enable-ssl part.

# ./configure –prefix=/usr/local/apache –with-mpm=prefork –enable-ssl –with-ssl=/usr/local/ssl –enable-log_config=static –enable-vhost_alias=static –enable-includes=static –enable-dir=static –enable-access=static –enable-mime=static –enable-mime_magic=static –enable-mods-shared=most –enable-cache=shared –enable-disk_cache=shared –enable-file_cache=shared –enable-mem_cache=shared

Tip: To check what these directives mean, you can issue ./configure –help .

# make

- If everything goes well, your fresh http will be installed in /usr/local/apache with the following command:

# make install

Installing PHP:

# cd /usr/src

# wget http://www.php.net/get/php-5.2.5.tar.gz/from/us.php.net/mirror (change this to a mirror available to you)

# tar zxf php-5.2.5.tar.gz

# cd php-5.2.5

- Same with http. The configure part will depend on your requirement.

# ./configure –with-config-file-path=/usr/local/apache/conf –with-apxs2=/usr/local/apache/bin/apxs –enable-calendar –enable-ftp –without-pgsql –with-zlib –with-openssl=/usr/local/ssl –with-mysql –with-mhash –with-mcrypt –with-curl –disable-cgi –enable-mbstring –enable-soap –with-bz2 –enable-sockets –enable-zip (If configure fails, read the error why the it failed and install first the dependencies then run again the configure.)

# make

# make test

# make install

To start the httpd service, execute

# /usr/local/apache/bin/apachectl start

You can create a symlink to your /etc/init.d so you can start apache by typing /etc/init.d/httpd start

# ln -s /usr/local/apache/bin/apachectl /etc/init.d/httpd

There you have it. You have successfully installed Apache with PHP on your webserver. I will continue this little howto with how to configure your webserver.