2020-11-03 Notes - When Using Termux On Android

Termux on Android partly brings the power of a linux pc to Android tablets. With Termux, we can run python, php, nodejs, git, etc... and even Ubuntu (GUI via VNC) on one's Android powered devices.

Quote from its F-droid:

1	`Termux combines powerful terminal emulation with an extensive Linux package collection.`

Here are some of my notes when using this interesting app.

Install

Termux

I used the F-droid link to install Termux and its plugins.

Do these things after the installation

This command will ask for storage permission for Termux:

termux-setup-storage

If you have root access, grant root access:

su

After that run exit command to log out root, and restart you Termux. Run it 2 times:

exit

Then update & upgrade packages

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pkg update

pkg upgrade

If you want to add more repositories: pkg install unstable-repo

If you have root access: pkg install root-repo

Create some config files

~/.bash_profile

In your root dir, modify or create this dot file ~/.bash_profile, you can add commands that you want Termux runs upon its starts up.

I use this config to change the default Termux dir to my work place dir, and add some alias commands.

For example, append these commands to ~/.bash_profile:

echo -e 'Be midful'
cal;
cd ~/storage/shared/myWorkPlace/

alias gitt='git add .;git commit -m "from Termux";git push;'

Note: Android /sdcard/ does not fully support chmod, (partally in /data/media/).

So you can not run ./file.sh directly. You need to run sh ./file.sh.

~/.nanorc

See .nanorc content in this respo

~/.vimrc

See .vimrc content in this respo

Note when installing package

Sometimes when you install a <package name>, it may say that package is not available (mainly because of Internet connection), don't give up easily, you may try again with these commands:

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pkg update
pkg search <package name>
pkg install <package name>

Some useful packages

Install them one by one with this partten: pkg install <package name>.

Or you can put them all together in one command: pkg install <packages name> <package name>

git
python
nodejs
php-apache
nano
vim-python
wget
curl
rsync
ripgrep
poppler

All in one command:

pkg install git python nodejs php-apache nano vim-python wget curl rsync ripgrep poppler

Notes & Guide

openssh - generate and add ssh with openssh

pkg install openssh

Create ~/.ssh dir to store your ssh keys, normally openssh will auto create this dir for you.

mkdir -p ~/.ssh

Generate ssh key:

ssh-keygen -t rsa -b 4096 -C "email@example.com"

Choose default location to store this key, provide passphrase

eval "$(ssh-agent -s)"

Then immediately run ssh-add -k ~/.ssh/id_rsa

Git

pkg install git

Set up

git config --global user.name "Panmux Android"

git config --global user.email "email@example.com"

git config --global core.editor nano

You can add ssh public key to your Github account: https://github.com/settings/ssh/new

rg RIPGREP

This grep tool is much faster than the ordinary grep. It supports Regex also.

pkg install ripgrep

This command will search for keyword in the entire current dir (including sub dirs).

It is really fast.

rg keyword

pdftotxt (pkg install poppler)

The command will be pdftotxt -enc UTF-8 inputfile.pdf.

I use this to convert pdf files to txt which allow me to do index for full text search later.

Sometimes, I also use rg keyword to quickly look for a keyword in many txt files inside the dir (and its subdirs also).

You can write a bash/shell script to do bulk convert:

# Credit: https://gist.github.com/tpaskhalis/214c3976ac08cb809d846e01135d9f5f
# Convert all pdf in FOLDER  (and its subdirs) to txt

FOLDER=/storage/ABC-SDCARD/Android/data/com.termux/files/_eBooks/

find "$FOLDER" -name '*.pdf' | while read i;
do
  echo "Processing $i"
  pdftotext -enc UTF-8 "$i"
done

vim-python

On Termux I mainly use nano to edit files. Sometimes I also use vim-python instead of vim.

This package will enable vim with python, which allow us tp install many powerful python-powered plugins.

Should use plugin manager for vim, here I use vim plug (search it on Github).

Add plugins that you want to install to ~/.vimrc.

Useful plugins: YouCompleteMe (for auto completion, search it on github, and should clone to the ~/.vim/plugged after that cd to YouCompleteMe and install mannualy with this command: python3 install.py --ts-completer

(This plugin is too big to install via vim plugin.)

Note --ts-completer is for Javascript family, you can add orther languages at the same time too.

In ~/.vimrc I still keep the install command, for later update:

" Plugin manager vim-plug https://github.com/junegunn/vim-plug
  call plug#begin('~/.vim/plugged')

  Plug 'ycm-core/YouCompleteMe', { 'do': './install.py --ts-completer' }
" Should git clone and install manually with python3 install.py --ts-completer
" --ts-completer is more updated than the tern one

  call plug#end()

Nodejs packages

Some useful packages. Install these with npm i -g install <package name>

express
http-server
live-server
epub-gen
prettier

Python packages

Some useful packages. Install these with pip3 install <package name>

1 2	`bs4 eng-to-ipa`

To install java on Termux

Install via this bash:

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pkg install wget

wget https: //raw.githubusercontent.com/MasterDevX/java/master/installjava && bash installjava

When the installation is finished without complaining any errors, and if you get error when running java -version

Then try to install tsu (root permission required) then run again with pkg install tsu

Then

sudo java --version

Or another way is, also with root permission, trying this method:

# from https://github.com/MasterDevX/Termux-Java/issues/7#issuecomment-653526860

su
export PATH=/data/data/com.termux/files/usr/bin:/data/data/com.termux/files/usr/bin/applets:$PATH
export LD_LIBRARY_PATH=/data/data/com.termux/files/usr/lib

If this does not work, you can remove these exports by using the below unset command
To list all env, run env, you should see a list of env

1 2	`unset PATH unset LD_LIBRARY_PATH`

To auto set this env variables on startup of bash, place the command:

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export PATH=/data/data/com.termux/files/usr/bin:/data/data/com.termux/files/usr/bin/applets:$PATH

export LD_LIBRARY_PATH=/data/data/com.termux/files/usr/lib

to/etc/profile.d/myprofile.sh

To run a .jar file you can try this command:

1	`sudo java -Xmx512M -Xms512M -jar filename.jar`

-Xmx512M and -Xms512M are to do some settings related to heap size. Google them to learn more.