Tagged: how_to

Termux is the ONE for Android!

Ever since I learned Terminal IDE was not supported for Android 5.0 Lollipop, I was heartbroken because there weren't any git client programs as good as git on Terminal IDE. I was using SGit but wasn't really happy because of lack of flexibility, features, and ease of use.

However, I finally found the one that works today! It's called Termux. Termux is a terminal emulator, just like Terminal IDE, but it comes with an extensive Linux package collections you can install and manage packages you want. Of course, it has git in its collection. So, I can say "bye, bye" to SGit now.

IMHO, Termux is for Android 5.0 Lollipop and above, and Terminal IDE is for Android 4.4 Kitkat and below.

Disclaimer:
The information in this site is the result of my researches in the Internet and of my experiences. It is solely used for my purpose and may not be suitable for others. I will NOT take any responsibility of end result after following these steps (although I will try to help if you send me your questions/problems).

Ok, the installation and configuration of Termux and git were easier than those of Terminal IDE in my opinion. Termux comes with a minimum base system. At this point, it doesn't do much so you'd need to install some packages. After getting Termux installed on my Galaxy Note 4, I opened it and typed below to update packages: $ apt update

With a bunch of messages, packages are updated. Then ran the following command to install git: $ apt install git

No problem here. I then installed ssh. As you may know, bitbucket.org offers two ways to access a git repository, https and ssh. I could go either way, but ssh is such a useful utility. So, I installed it at this time: $ apt install openssh

Now, the fun part starts - configuration. I've set up my web server Bit Web Server to look into /sdcard/www/ for source codes, so I tried to clone codes from my git repo, but it failed with "Permission Denied" error. Hmm... is this because Termux doesn't have write permissions for security? Well, no problem. I can seem to clone into /data/data/com.termux/home/ and copy the source codes into /sdcard/www/: $ git clone https://[user_name]@bitbucket.org/[repo_name]/[repo_name].git $ cp -r [repo_name] /sdcard/www/

After copying into the www directory, I learned that I can still run git commands like git push, git pull, etc... without any errors. Fantastic!! This means I don't need to copy back and forth between /data/data/com.termux/home/ and /sdcard/www/ every time I make updates.

Now, it's time to finish up by configuring git and Termux's user home environments.

For git, ran the following commands to set up user information: $ git config user.name "[username]" $ git config user.email "[username]@[server]"

Then edited the .bashrc file for some aliases. I created ~/.bashrc with some start up configurations for the shell, but it didn't seem to be taking it after restarting Termux. After poking around, I found a bashrc file that seems to be globally used for Termux in /data/data/com.termux/files/usr/etc/: $ cd /data/data/com.termux/files/usr/etc/ $ vim bash.bashrc --------------------------------- export GIT_AUTHOR_NAME="[username]" export GIT_AUTHOR_EMAIL="[username]@[server]" export GIT_COMMITTER_NAME=$GIT_AUTHOR_NAME export GIT_COMMITTER_EMAIL=$GIT_AUTHOR_EMAIL PS1='\[\e[00;32m\]\A \[\e[00;91m\]\u\[\e[01;93m\]@\h\[\e[00;37m\][\[\e[01;34m\]\w\[\e[00;37m\]]\n\[\e[47m\]\[\e[1;30m\]$\[\e[00m\] ' set -o vi

With all of these, git is ready for Android 5.0 Lollipop!

That's all!
-gibb

Copying Files From Android Kitkat (4.4.4) to Slackware

I didn't know until I tried myself but when I connected my Samsung Galaxy Note 4 to my slacky64 (Slackware Linux) via USB, I no longer had an option to connect it as USB Mass Storage (UMS) like it did with other flash drives. In stead, it gave me two options: MTP and PTP. Hmm... what the heck are these?

mtp_php

Apparently, the old way of accessing the storage device had several drawbacks. One being how it was making its storage partition available to foreign systems. Whenever another system accessed the phone's storage area, it needed exclusive access to there, which means the entire storage partition was dedicated to that system and as long as that system was accessing there, the phone itself couldn't access any files or apps stored in that area. Also, this could easily mess up (or corrupt) the storage partition.

Another reason was the type of its file system. Because its storage partition needed to be available to various systems, mostly for Windows devices, it was formatted as the FAT file system (Duh...). FAT is an older and slower file system without the concept of file ownership. Not to mention Microsoft holds patents for which they demand royalties from OEM's for long file name support on the FAT file system, etc...

So what are MTP and PTP?

MTP (Media Transfer Protocol) is a subset of PTP (Picture Transfer Protocol) communication protocols that allow transferring media files from and to portable devices. These protocols have been around for a while but they are new to Android. They are considered better solutions to the problems UMS had. When a foreign system accesses the phone via MTP, it sends queries to Android and Android returns with the list of files requested. Then it downloads files. This allows access to file levels rather than exclusively opens up the entire storage portion and also allows Android choose which files to present.

This also enables Android format its storage device with ext3/ext4 or any other file systems - no longer limited to FAT!

PTP works the similar way and is mostly used by digital cameras.

For more information, please refer to Android USB Connections explained MTP, PTP, and USB Mass Storage

Now, some terminologies are out of the way, I tried transferring some photos from my Note 4 to slacky64 using MTP. Hm? It's very slow loading photos and it's even slower transferring them. Also, after photos were copied over, not only were their timestamp changed to current date and time instead of date and time taken but my photo viewer program also couldn't display them. That's not good...

I was hoping PTP would work better but no luck. It was even worse; I couldn't even get photos listed in my file manager.

Now, I went on a hunt for better ways to transfer photos.

I tried sftp and scp (with an option to retain the original timestamp) but its process kept dying on me while in the middle of transferring files.

I was kind of frustrated with this. Then, I found dukto in Google Play. It had good reviews and high rating points. I was a bit concerned about this program needing be installed on all devices, but, what the heck, as long as it'll transfer photos, I would be happy at this point.

Installation on the Android device was breeze. There were some extra steps needed to install it on my Slackware system because dukto was available in binary packages for CentOS, Fedora, OpenSUSE, RHEL, and Ubuntu and no source. This means the rpm package needs to be converted to the tgz format with the rpm2tgz command.

Converting rpm with rpm2tgz

Slackware comes with a handy utility to convert rpm files to tgz files. All you need is to run rpm2tgz with rpm file: # cd /tmp # rpm2tgz dukto-6.0-13.1.x86_64.rpm ... Slackware package /tmp/dukto-6.0-13.1.x86_64.tgz created # installpkg /tmp/dukto-6.0-13.1.x86_64.tgz Verifying package dukto-6.0-13.1.x86_64.tgz. Installing package dukto-6.0-13.1.x86_64.tgz: PACKAGE DESCRIPTION: Package dukto-6.0-13.1.x86_64.tgz installed. #

VoilĂ ! The conversion and installation went successful. To run the program, execute dukto: $ dukto

dukto_slacky64

Transferring Files

To transfer file from the Android device to PC:

  1. Open dukto on both devices
  2. On the Android device, click on the icon you want to send your files
  3. Choose Send some files and folders if you are sending files
  4. Locate files you wish to send
  5. Check files
  6. Click on the Send icon

Once selected files have been transferred, the confirmation message is displayed.

dukto_send

Transferring files was snap. In my opinion, the best way to transfer files for Android devices. Although this was the best method by far, I should note that the timestamp of transferred files was still changed. At this point, it's no longer a big issue because file name contains the date taken and this info as well as the time were embedded to file itself.

There are some drawbacks of this program:

  • There is no "select all" button. If you want to copy 100 files, you need to select all those files manually (or you could select a folder)
  • dukto needs to be running on both devices simultaneously
  • dukto must be active while transferring files; otherwise, it halts the process. This means no screensaver as well

Disclaimer:
The information in this site is the result of my researches in the Internet and of my experiences. It is solely used for my purpose and may not be suitable for others. I will NOT take any responsibility of end result after following these steps (although I will try to help if you send me your questions/problems).

That's all!
-gibb

Debian Wheezy (7.5): Name-Based Web Sites on a Single IP Address (vhosts)

Configuring virtual hosting with Debian Wheezy has a little different steps from that with Slackware. To avoid from getting myself confused (and hopefully help someone else to set their virtual host sites), these are the steps I used for my local sites.

Disclaimer:
The information in this site is the result of my researches in the Internet and of my experiences. It is solely used for my purpose and may not be suitable for others. I will NOT take any responsibility of end result after following these steps (although I will try to help if you send me your questions/problems).

1) Disabling Default Virtual Host

First, let's disable the default Apache virtual host with a2dissite. What this command do is simply removing a symlink to /etc/apache2/sites-enabled/. # a2dissite default

2) Creating a New Directory and Setting Permissions

It's necessary to create a directory where site's website files and logs reside and grant ownership of the directory to the user instead of keeping it on the root system. For example, I'm setting up for siteA.org and siteB.org.

siteA.org
# mkdir -p /var/www/siteA.org/public_html # mkdir /var/www/siteA.org/logs # chown -R [$user]:[$group] /var/www/siteA.org/public_html
siteB.org
# mkdir -p /var/www/siteB/public_html # mkdir /var/www/siteB.org/logs # chown -R [$user]:[$group] /var/www/siteB.org/public_html

3) Creating Config files

Each virtual host needs own configuration file placed in /etc/apache2/sites-available/ directory. Each configuration file is as follow. Make sure that you have all directories specified in each conf file exist before you restart the apache process; otherwise, it'll fail to start.

siteA.org

# vim /etc/apache2/sites-available/siteA.org.conf ------------------------------------ <VirtualHost *:80> ServerAdmin webmaster@siteA.org ServerName siteA.org ServerAlias www.siteA.org DocumentRoot /var/www/siteA.org/public_html <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory /var/www/siteA.org/public_html/> Options Indexes FollowSymLinks AllowOverride None Order allow,deny allow from all </Directory> ErrorLog /var/www/siteA.org/logs/error.log CustomLog /var/www/siteA.org/logs/access.log combined </VirtualHost>

siteB.org

# vim /etc/apache2/sites-available/siteB.org.conf ------------------------------------ <VirtualHost *:80> ServerAdmin webmaster@siteA.org ServerName siteB.org ServerAlias www.siteB.org DocumentRoot /var/www/siteB.org/public_html <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory /var/www/siteB.org/public_html/> Options Indexes FollowSymLinks AllowOverride None Order allow,deny allow from all </Directory> ErrorLog /var/www/siteB.org/logs/error.log CustomLog /var/www/siteB.org/logs/access.log combined </VirtualHost>

4) Enabling the Sites

Now activate the host: # a2ensite siteA.org.conf # a2ensite siteB.org.conf

5) Restarting Apache

Restart the Apache server to initialize the changes: # service apache2 restart

6) Setting Up Local Host

Edit /etc/hosts so that the sites can be found by name: # vim /etc/hosts ------------------------------------ 127.0.0.1 localhost siteA siteB

That's all!
-gibb

Debian Wheezy (7.5): Accessing the Encrypted Partition From the Recovery System

Continued from my previous post, Debian Wheezy (7.5): Encrypted Root Filesystem on laptop.

In my previous post, I created an extra partition for recovery system that could be used to repair the main system in a situation where it becomes corrupted or un-bootable. But how exactly can I access it from the recovery system? Well, steps described below is something I would try, in other words, just a theory. If you know a better (correct) way, or if I'm doing wrong, please feel free to comment!

Disclaimer:
The information in this site is the result of my researches in the Internet and of my experiences. It is solely used for my purpose and may not be suitable for others. I will NOT take any responsibility of end result after following these steps (although I will try to help if you send me your questions/problems).

Booting Into the Recovery System

At the GRUB menu, choose the Recovery system. In my case it's on /dev/sda2.
debian_install_4

Accessing Encrypted Device with `cryptsetup luksOpen`

First, let's see my partition layout: # parted (parted) p Model: ATA WDC WD3200BEKT-6 (scsi) Disk /dev/sda: 320GB Sector Size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 310GB 310GB 2 310GB 320GB 10.1GB ext4 (parted) q

Since /dev/sda1 is encrypted with crypt-luks, normal mount command would not work. # mount /dev/sda1 /mnt/main mount: unknown filesystem type 'crypto_LUKS'

So it needs to be opened to access the encrypted device. This process requires your passphrase. This will create /dev/mapper/unlocked. # cryptsetup luksOpen /dev/sda1 unlocked Enter passphrase for /dev/sda1:

Can we mount the device now? Nope. Because it's LVM.

Accessing LVM

First install lvm2. # apt-get install lvm2

SIDE NOTE:
If you get the following warnings after executing above command:

update-initramfs: Generating /boot/initrd.img-3.2.0-4-amd64
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168f-2.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168f-1.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8105e-1.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168e-3.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168e-2.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168e-1.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168d-2.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168d-1.fw for module r8169

You need to add contrib and non-free repositories to /etc/apt/sources.list: # vim /etc/apt/sources.list -------------------------------------- deb http://ftp.us.debian.org/debian wheezy main contrib non-free # apt-get update Then install the firmware-realtek package: # apt-get install firmware-realtek

Then load the necessary module. # modprobe dm-mod

Scan the system for LVM volumes and identify the volume group name in the output. # vgscan Reading all physical volumes. This may take a while... Found volume group "debian" using metadata type lvm2

Activate the volume. # vgchange -ay debian 2 logical volume(s) in volume group "debian" now active

Then find the logical volume that has the root filesystem # lvs LV VG Attr LSize Pool Origin Data% Move Log Copy% Convert root debian -wi-a--- 284.98g swap debian -wi-a--- 3.72g

Mounting It Now!

Now all the preparation is done. It's time to mount it. # mount -o ro,user /dev/debian/root /mnt/unlocked # ls mnt/unlocked bin etc lib media proc sbin sys var boot home lib64 mnt root selinux tmp vmlinuz dev initrd.img lost+found opt run srv usr

VoilĂ ! Successfully mounted!

That's all!
-gibb

Debian Wheezy (7.5): Encrypted Root Filesystem on laptop

I'm not a distro-hopper. Well, that's what I thought but I'm probably wrong (and nothing wrong with being a distro-hopper!). On my main system, I'm using Slackware since its version 9 or 10. However, on my laptop (HP Pavilion dm3-1130us), I tried RHCE, Fedora, Xubuntu, Mint, CrunchBang, Arch, and FreeBSD. Each distro had its pros and cons but it didn't really stick to me. I liked FreeBSD the best among them but it drained the battery and heated up my laptop compared to other distros. Also I couldn't get some of hardware components (ex: built-in webcam) working. I believe FreeBSD is an excellent OS for servers but probably not for laptops so much. So, I was in a quest for another distro again and decided to try on Debian.

Disclaimer: The information in this site is the result of my researches in the Internet and of my experiences. It is solely used for my purpose and may not be suitable for others. I will NOT take any responsibility of end result after following these steps (although I will try to help if you send me your questions/problems).

Now onto Debian. As other distributions, I wanted to try encrypted disk/filesystem(s) for my laptop. After a bit of research, I came across to this article. Interesting. My laptop doesn't have a CD/DVD drive, either, but I never thought of having a recovery partition in case of emergency. So I decided to give it a try with this method. Since this article is a bit outdated, I'll describe it with most recent version of Debian (Wheezy) and add some steps.

1. Creating Bootable USB Stick

Download the netinst.iso image from Debian website and create a bootable USB stick. # dd if=debian-7.5-0-amd64-netinst.iso of=/dev/sdX

2. Setting Up Recovery System

Start the Debian installer. Since I love OpenBox, I select below options for the installation.
Advanced options -> Alternative desktop environments -> LXDE -> Graphical install
Follow the installer until you get to set the hostname. I set it as debianrecov for recovery. Follow it until you get to "Partition disks" and select Manual. Here is the partition scheme to use:
  • Main partition for LVM and encrypted, taking up the whole disk minus 3GB. Set it as Do not use for now.
  • 3GB recovery partition at the end of the disk. This will be /boot for the main system. (3GB is an arbitrary size I picked. I tried with 1GB and the installation failed when installing packages.)
    - Set it as ext4 mounted as "/" - Set its label as "recovery"
Choose Finish partitioning and write changes to disk. It'll then warn you that there is no partition for swap space and ask you whether to return to the partition menu. Just select No and follow the rest of the installation. Reboot your system and make sure it boots up without any issues.

3. Setting Up Main System

Now boot the Debian installer again. Select the same options for the installation and follow it until you get to "Partition disks". Select Manual. Select the main partition and hit the Continue button. Then choose physical volume for encryption for "Use as:". debian_install_1 Select "Done setting up the partition". Next select "Configure encrypted volumes". Then "Create encrypted volumes" and choose the main partition. After selecting "Yes" for erasing data on the partition, it'll start randomizing it. This will take very long time (on my laptop, it took more than 10 hours). When it's done, it'll ask for a passphrase. This is the phrase you type at every boot and it is not recoverable so don't forget it! Select the contents of the "disk" Encrypted volume and debian_install_2 Next, select physical volume for LVM for "Use as:" and choose "Done setting up the partition". Then select Configure the Logical Volume Manager and create a Volume Group. The original article uses the hostname for the Volume Group to reduce confusion if the disk is plugged into another machine for disaster recovery. I think that's a great idea. Create a Logical Volume called swap. If you plan to use suspend-to-disk, this needs to be at least as large as your RAM. Create a Logical Volume called root. Set the swap Logical Volume you just created to be used as a swap area and your root Logical Volume to be used as ext4 mounted at "/". Also set your recovery partition to be used as ext4, mounted on "/boot", and the format partition option to "no, keep existing data". This is how the partition layout looks like: debian_install_3 Proceed with the rest of the installation and reboot the system when it's done.

4. Making Them Dual-boot

In the original article, it now talks about setting up dual-boot. Debian Wheezy uses GRUB2 and menu.lst is no longer available. However, it should automatically detect your recovery system and it should look like below during GRUB menu: debian_install_4 If your recovery system is missing, you could try running the update-grub2 command in your main system: # update-grub2 Generating grub.cfg ... Found linux image: /boot/vmlinuz-3.2.0-4-amd64 Found initrd image: /boot/initrd.img-3.2.0-4-amd64 Found Debian GNU/Linux (7.5) on /dev/sda2 done If update-grub2 did not work, make sure that the recovery partition was set to be ext4, mounted on "/boot", and the format partition option was set to "no, keep existing data" at the end of Step 3 above. Tomorrow, I'll talk about accessing main system's area from recovery system. That's all! -gibb