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sudo is a wrapper script to drop to any supported shell or execute shell script files or their text passed as an argument with superuser (root) context in Termux App. Check the Usage and Command Types sections for more info on what type of commands can be run. sudo stands for superuser do.

The device must be rooted and ideally Termux must have been granted root permissions by your root manager app like SuperSU or Magisk for the sudo script to work.

Make sure to read the Worthy Of Note section, specially the RC File Variables section. This is very important, specially if you were previously using termux-sudo by st42.

To use sudo with Termux:Tasker plugin and RUN_COMMAND Intent, check Termux:Tasker Setup Instructions section for details on how to them up. The Tasker App or your plugin host app must be granted com.termux.permission.RUN_COMMAND permission. The sudo script must be installed at $PREFIX/bin/sudo. The allow-external-apps property must also be set to true in ~/.termux/termux.properties file since the $PREFIX/bin/sudo absolute path is outside the ~/.termux/tasker/ directory. For android >= 10, the Termux App should also be granted Draw Over Apps permission so that foreground commands automatically start executing without the user having to manually click the Termux notification in the status bar dropdown notifications list for the commands to start. Check Templates section for template tasks that can be run used to run sudo from Termux:Tasker plugin and RUN_COMMAND Intent.

Note that this sudo by agnostic-apollo, termux-sudo by st42 and tsu by cswl are competing packages/scripts and ideally only one of them should be used. Also note that when you install or update tsu, it creates a symlink at $PREFIX/bin/sudo for its own sudo command. So installing or updating tsu after installing sudo by agnostic-apollo will replace the sudo by agnostic-apollo script file with the tsu symlink and installing sudo by agnostic-apollo if you have already installed tsu will break its own sudo command.

If you want to run commands in termux user context, check tudo.

Contents

Dependencies

Using sudo directly from inside termux terminal session does not have any specific version requirements, other than bash version >= 4.1. However, to use sudo with Termux:Tasker plugin and RUN_COMMAND Intent requires the following versions to be installed. Check Passing Arguments section and Termux:Tasker Setup Instructions section for details.

Downloads

Latest version is v0.1.0.

Install Instructions For Termux In Android

The sudo file should be placed in termux bin directory /data/data/com.termux/files/usr/bin.
It should have termux uid:gid ownership and have executable 700 permission before it can be run directly without bash.

  1. Download the sudo file.

    • Download to termux bin directory directly from github using curl using a non-root termux shell.
      Run pkg install curl to install curl first.

      • Latest release:

        curl -L 'https://github.com/agnostic-apollo/sudo/releases/latest/download/sudo' -o "/data/data/com.termux/files/usr/bin/sudo"

      • Specific release:

        curl -L 'https://github.com/agnostic-apollo/sudo/releases/download/v0.1.0/sudo' -o "/data/data/com.termux/files/usr/bin/sudo"

      • Master Branch may be unstable:

        curl -L 'https://github.com/agnostic-apollo/sudo/raw/master/sudo' -o "/data/data/com.termux/files/usr/bin/sudo"

    • Download sudo file manually from github to the android download directory and then copy it to termux bin directory.

      You can download the sudo file from a github release from the Assets dropdown menu.

      You can also download it from a specific github branch/tag by opening the sudo file from the Code section.
      Right-click or hold the Raw button at the top and select Download/Save link.

      Then copy the file to termux bin directory using cat command below or use a root file browser to manually place it.

      cat "/storage/emulated/0/Download/sudo" > "/data/data/com.termux/files/usr/bin/sudo"

  2. Set termux ownership and executable permissions.

    • If you used a curl or cat to copy the file, then use a non-root termux shell to set ownership and permissions with chown and chmod commands respectively:

      export termux_bin_path="/data/data/com.termux/files/usr/bin"; export owner="$(stat -c "%u" "$termux_bin_path")"; chown "$owner:$owner" "$termux_bin_path/sudo" && chmod 700 "$termux_bin_path/sudo";

    • If you used a root file browser to copy the file, then use su to start a root shell to set ownership and permissions with chown and chmod commands respectively:

      export termux_bin_path="/data/data/com.termux/files/usr/bin"; export owner="$(stat -c "%u" "$termux_bin_path")"; su -c "chown \"$owner:$owner\" \"$termux_bin_path/sudo\" && chmod 700 \"$termux_bin_path/sudo\"";

    • Or manually set them with your root file browser. You can find termux uid and gid by running the command id -u in a non-root termux shell or by checking the properties of the termux bin directory from your root file browser.

Current Features

Planned Features

-

Usage

sudo is a wrapper script to drop to the supported shells or execute
shell script files or their text passed as an argument with super
user (root) context in termux.


Usage:
  sudo [command_options] su
  sudo [command_options] asu
  sudo [command_options] [-p] <command> [command_args]
  sudo [command_options] -s <core_script> [core_script_args]


Available command_options:
  [ -h | --help ]    display this help screen
  [ --help-extra ]   display more help about how sudo command works
  [ --version ]      display version
  [ -v | -vv ]       set verbose level to 1 or 2
  [ -a ]             force set priority to android paths for path
                     command type
  [ -b ]             go back to last activity after running core_script
  [ -B ]             run core_script in background
  [ -c ]             clear shell after running core_script
  [ -d ]             disable stdin for core_script
  [ -D ]             disable preserve environment for su
  [ -e ]             exit early if core_script fails
  [ -E ]             exec interactive shell or the path command
  [ -f ]             force use temp script file for core_script
  [ -F ]             consider core_script to be a path to script file
                     instead of script text
  [ -H ]             same sudo post shell home as sudo shell home
  [ -i ]             run interactive sudo post shell after running
                     core_script
  [ -l ]             go to launcher activtiy after running core_script
  [ -L ]             export all existing paths in '$LD_LIBRARY_PATH'
                     variable
  [ -n ]             redirect stderr to /dev/null for core_script
  [ -N ]             redirect stdout and stderr to /dev/null for
                     core_script
  [ -o ]             redirect stderr to stdout for core_script
  [ -O ]             redirect stdout to stderr for core_script
  [ -p ]             set 'path' as command type [default]
  [ -P ]             export all existing paths in '$PATH' variable
  [ -r ]             parse commands as per RUN_COMMAND intent rules
  [ -R ]             use root for searching and validating paths
  [ -s ]             set 'script' as command type
  [ -S ]             same sudo post shell as sudo shell
  [ --comma-alternative=<alternative> ]
                     comma alternative character to be used for
                     the `-r` option instead of the default
  [ --dry-run ]
                     do not execute sudo commands
  [ --export-paths=<paths> ]
                     additional paths to export in PATH variable,
                     separated with colons ':'
  [ --export-ld-lib-paths=<paths> ]
                     additional paths to export in LD_LIBRARY_PATH
                     variable, separated with colons ':'
  [ --force-remount-ro ]
                     force remount rootfs and system partitions back
                     to ro after sudo commands
  [ --hold[=<string>] ]
                     hold sudo from exiting until string is entered,
                     defaults to any character if string is not passed
  [ --hold-if-fail ]
                     if '--hold' option is passed, then only hold if
                     exit code of sudo does not equal '0'
  [ --list-interactive-shells ]
                     display list of supported interactive shells
  [ --list-script-shells ]
                     display list of supported script shells
  [ --no-create-rc ]
                     do not create rc files automatically
  [ --no-create-hist ]
                     do not create history files automatically
  [ --no-hist ]
                     do not save history for sudo shell and sudo post
                     shell
  [ --no-log-args ]
                     do not log arguments and core_script content
                     when verbose mode is enabled
  [ --no-remount-ro ]
                     do not remount rootfs and system partitions back
                     to ro after sudo commands
  [ --keep-temp ]
                     do not delete sudo temp directory on exit
  [ --post-shell=<shell> ]
                     name or absolute path for sudo post shell
  [ --post-shell-home=<path> ]
                     absolute path for sudo post shell home
  [ --post-shell-options=<options> ]
                     additional options to pass to sudo post shell
  [ --post-shell-post-commands=<commands> ]
                     bash commands to run after sudo post shell
  [ --post-shell-pre-commands=<commands> ]
                     bash commands to run before sudo post shell
  [ --post-shell-stdin-string=<string> ]
                     string to pass as stdin to sudo post shell
  [ --remove-prev-temp ]
                     remove temp files and directories created on
                     previous runs of sudo command
  [ --script-decode ]
                     consider the core_script as base64
                     encoded that should be decoded before execution
  [ --script-name=<name> ]
                     filename to use for the core_script temp file
                     created in '.sudo.temp.XXXXXX' directory instead
                     of 'sudo_core_script'
  [ --script-redirect=<mode/string> ]
                     core_script redirect mode for stdout and stderr
  [ --shell=<shell> ]
                     name or absolute path for sudo shell
  [ --shell-home=<path> ]
                     absolute path for sudo shell home
  [ --shell-options=<options> ]
                     additional options to pass to sudo shell
  [ --shell-post-commands=<commands> ]
                     bash commands to run after sudo shell for script
                     command type
  [ --shell-pre-commands=<commands> ]
                     bash commands to run before sudo shell
  [ --shell-stdin-string=<string> ]
                     string to pass as stdin to sudo shell for script
                     command type
  [ --sleep=<seconds> ]
                     sleep for x seconds before exiting sudo
  [ --sleep-if-fail ]
                     if '--sleep' option is passed, then only sleep if
                     exit code of sudo does not equal '0'
  [ --su-env-options=<options> ]
                     additional options to pass to su that sets up the
                     sudo environment
  [ --su-run-options=<options> ]
                     additional options to pass to su that runs the
                     final sudo command_type command
  [ --title=<title> ]
                     title for sudo shell terminal
  [ --work-dir=<path> ]
                     absolute path for working directory


Set verbose level to 1 or 2 to get more info when running sudo command.

Pass '--dry-run' option with verbose mode enabled to see the commands
that will be run without actually executing them.

Visit https://github.com/agnostic-apollo/sudo for more help on how
sudo command works.



The 'su' command type drops to an interactive shell in superuser (root)
context for any of the supported interactive shells. To drop to a root
'bash' shell, just run 'sudo su'. The priority will be set to termux
bin and library paths in '$PATH' and '$LD_LIBRARY_PATH' variables.
Use the '--shell' option to set the interactive shell to use.


The 'asu' command type is the same as 'su' command type but
instead the priority will be set to android bin and library paths in
'$PATH' and '$LD_LIBRARY_PATH' variables.
Use the '--shell' option to set the interactive shell to use.


The 'path' command type runs a single command in superuser (root)
context. You can use it just by running 'sudo <command> [command_args]'
where 'command' is the executable you want to run and 'command_args'
are any optional arguments to it. The 'command' will be run within a
'bash' shell. Priority is given to termux bin and library paths unless
'command' exists in '/system' partition.
To call the 'su' binary, run the 'sudo -p su [user]' command.


The 'script' command type takes any script text or path to a script
file for any of the supported script shells referred as 'sudo shell',
and executes the script with any optional arguments with the desired
script shell. This can be done by running the
'sudo -s <core_script> [core_script_args]' command.
The 'core_script' will be considered a 'bash' script by default.
The 'core_script' will be passed to the desired shell using
process substitution or after storing the 'core_script' in a temp file
in a temp directory in 'sudo shell' home
'$HOME/.sudo.temp.XXXXXX/sudo_core_script' and passing the path to
the desired shell, where 'XXXXXX' is a randomly generated string.
The method is automatically chosen based on the script shell
capabilities. The '-f' option can be used to force the usage of a
script file. The '-F' option can passed so that the 'core_script'
is considered as a path to script file that should be passed to
'sudo shell' directly instead of considering it as a script text.
Use the '--shell' option to set the script shell to use.
Use the '--post-shell' option to set the interactive shell to use if
'-i' option is passed.


Run "exit" command of your shell to exit interactive shells and return
to the termux shell.

Command Types

su

The su command type drops to an interactive shell in superuser (root) context for any of the supported Interactive Shells. su stands for substitute user which in this case will be the superuser (root). To drop to a root bash shell, just run sudo su. The priority will be set to termux bin and library paths in $PATH and $LD_LIBRARY_PATH variables. Check the PATH and LD_LIBRARY_PATH Priorities section for more info.

Note that su is just a command type and does not represent the su binary itself. Use the path command type to run the sudo -p su [user] command instead for calling the su binary.   

asu

The asu command type is the same as su command type but instead the priority will be set to android bin and library paths in $PATH and $LD_LIBRARY_PATH variables. Check the PATH and LD_LIBRARY_PATH Priorities section for more info.   

path

The path command type runs a single command in superuser (root) context. You can use it just by running sudo <command> [command_args] where command is the executable you want to run and command_args are any optional arguments you want to pass to it.

The command will be run within a bash shell. Priority is given to termux bin and library paths unless command exists in /system partition. sudo <command> will not work if executable to be run does not have proper ownership or executable permissions set that disallows termux user to read or execute it if sudo command itself is being run from the termux context and -R option is not passed. The command must be an absolute path to an executable, or basename to an executable in the current directory or in a directory listed in the final $PATH variable that is to be exported by the sudo command. If it is not found, sudo will exit with an error.

The path command type is of course useful for running single commands with root context without having to drop to a root shell, but its also very useful for running commands in /system partition that require priorities to be set to android library paths and which fail otherwise with errors like CANNOT LINK EXECUTABLE and cannot locate symbol some_symbol referenced by /lib..... The sudo command will automatically detect if the command exists in /system partition and set priorities to android bin and library paths in $PATH and $LD_LIBRARY_PATH variables. So running sudo dumpsys will just work. You can also force setting priority to android paths by passing the -a option or to run a binary in /system partition instead of that in termux bin paths.

You can also use sudo <command> even if you are inside of a sudo su root shell and it will work without having to switch to sudo asu or exporting variables to change priority.

You can also run the sudo -p su [user] or sudo -p /path/to/su [user] commands to call the su binary for dropping to a shell for a specific user or even run a command for a specific user, like sudo -p su -c "logcat" system. Note that if you do not provide an absolute path to the su binary and just run sudo -p su, then the termux su wrapper script will be called which is stored at $PREFIX/bin/su which automatically tries to find the su binary and unsets LD_LIBRARY_PATH and LD_PRELOAD variables. You can check its contents with cat "$PREFIX/bin/su". The variables will be also be unset by the sudo script if it detects you are trying to run a su binary.

Check the -a and -r command options that can be specifically used with the path command type.   

script

The script command type takes any script text or path to a script file for any of the supported Script Shells referred as sudo shell, and executes the script with any optional arguments with the desired script shell. This can be done by running the sudo -s <core_script> [core_script_args] command. The core_script will be considered a bash script by default.

The script command type is incredibly useful for usage with termux plugins like Termux:Tasker or RUN_COMMAND Intent. Currently, any script files that need to be run need to be created in ~/.termux/tasker/ directory, at least for Termux:Tasker. It may get inconvenient to create physical script files for each type of command you want to run. These script files are also neither part of backups of plugin host apps like Tasker and require separate backup methods and nor are part of project configs shared with other people or even between your own devices, and so the scripts need to be added manually to the ~/.termux/tasker/ directory on each device. To solve such issues and to dynamically define scripts of different interpreted languages inside your plugin host app like Tasker in local variables (all lowercase %core_script) of a task and to pass them to Termux as arguments instead of creating script files, the script command type can be used. The termux environment will also be properly loaded like setting LD_PRELOAD etc before running the commands.

The core_script will be passed to the desired shell using Process Substitution or after storing the core_script in a temp file in a temp directory in sudo shell home $HOME/.sudo.temp.XXXXXX/sudo_core_script and passing the path to the desired shell, where XXXXXX is a randomly generated string. The method is automatically chosen based on the script shell capabilities. The -f option can be used to force the usage of a script file. If the temp directory is created, it will be empty other than the sudo_core_script file and will be unique for each execution of the script, which the script can use for other temporary stuff without having to worry about cleanup since the temp directory will be automatically removed when sudo command exits unless --keep-temp is passed. The temp directory path will also be exported in the $SUDO_SCRIPT_DIR environment variable which can be used by the core_script, post shell and --*shell-*-commands options, like --shell-pre-commands='cd "$SUDO_SCRIPT_DIR"'. The $HOME refers to the sudo shell home.

For bash zsh fish ksh python python2 ruby perl lua5.2 lua5.3 lua5.4, process substitution is used by default and for dash sh node php a file is used. If the usage of process substitution is breaking for some complex scripts of some specific shell, please report the issue.

The -F option can be passed so that the core_script is considered as a path to a script file that should be passed to sudo shell directly instead of considering it as a script text.

The core_script can optionally not be passed or passed as an empty string so that other "features" of the script command type can still be used without calling the script shell.

It may also be important to automatically open an interactive shell after the core_script completes. This can be done by using the -i option along with --post-shell* options. The sudo post shell can be any of the supported Interactive Shells and defaults to bash. The same shell as the script sudo shell can also be used for sudo post shell by passing the -S option as long as the sudo shell exists in the list of supported interactive shells. The environment variable $SUDO_SCRIPT_EXIT_CODE will be exported containing the exit code of the core_script before the interactive shell is started. Running an interactive shell will also keep the terminal session open after commands complete which is normally closed automatically when commands are run with the plugin or intents, although the --hold option can also be used for this.

You can define your own exit traps inside the core_script, but DO NOT define them outside it with the --*shell-*-commands options since sudo defines its own trap function sudo_script_trap for cleanup, killing child processes and to exit with the trap signal exit code. If you want to handle traps outside the core_script, then define a function named sudo_script_custom_trap which will automatically be called by sudo_script_trap. The function will be sent TERM, INT, HUP, QUIT as $1 for the respective trap signals. For the EXIT signal the $1 will not be passed. Do not exit inside the sudo_script_custom_trap function. If the sudo_script_custom_trap function exits with exit code 0, then the sudo_script_trap will continue to exit with the original trap signal exit code. If it exits with exit code 125 ECANCELED, then sudo_script_trap will consider that as a cancellation and will just return without running any other trap commands. If any other exit code is returned, then the sudo_script_trap will use that as exit code instead of the original trap signal exit code.

Check the -b, -B, -c, -d, -e, -E, -f, -F, -l, -n, N, -o, O, -r, --remove-prev-temp, --keep-temp, --shell*, --post-shell*, --script-decode, --script-redirect, --script-name command options that can be specifically used with the script command type.

Supported Shells

The bash shell is the default interactive and script shell and must exist at $PREFIX/bin/bash with ownership and permissions allowing termux user to read and execute it. The --shell and --post-shell options can be used to change the default shells. The path command type always uses the bash shell and command options are ignored. Normally, shells are not validated as the root user unless -R is passed so they must have proper ownership or executable permissions set that allows termux user to read and execute them.

The exported environmental variables $SUDO_SHELL_PS1 and $SUDO_POST_SHELL_PS1 can be used to change the default $PS1 values of the shell, provided that the shell uses it. Check the Modifying Default Values section for more info on sudo environmental variables and modifying default values.

Interactive Shells

The supported interactive shells are: bash zsh dash sh fish python ruby pry node perl lua5.2 lua5.3 lua5.4 php python2 ksh

These shells can be used for the su and asu command types like sudo --shell=<shell> su and sudo --shell=<shell> asu and also as post shell for script command type when the -i option is passed like sudo -si --post-shell=<shell> <core_script> to start an interactive shell after script commands complete.

The bash shell is automatically chosen as the default interactive shell if the --shell or --post-shell options are not passed to set a specific shell. You can pass the name of a shell listed in the supported shells list like --shell=zsh or an absolute path like --shell=/path/to/zsh. The $PREFIX/ and ~/ prefixes are also supported, like $PREFIX/bin/zsh or ~/zsh.

For perl, the interactive shell is started using rlwrap, which must be installed. Use pkg install rlwrap to install.

Script Shells

The supported script shells are: bash zsh dash sh fish python ruby node perl lua5.2 lua5.3 lua5.4 php python2 ksh

These shells can be used for the script command type like sudo -s --shell=<shell> <core_script>.

The bash shell is automatically chosen as the default script shell if the --shell option is not passed to set a specific shell. You can pass the name of a shell listed in the supported shells list like --shell=zsh or an absolute path like --shell=/path/to/zsh. The $PREFIX/ and ~/ prefixes are also supported, like $PREFIX/bin/zsh or ~/zsh.

Command Options

The $PREFIX/ and ~/ prefixes are supported for all command options that take in absolute paths as arguments. The $PREFIX/ is a shortcut for the termux prefix directory /data/data/com.termux/files/usr/. The ~/ is a shortcut for the termux home directory /data/data/com.termux/files/home/. Note that if the paths with shortcuts are not surrounded with single quotes, they will expanded by the local shell before being passed to the sudo script instead of the sudo script manually expanding them. Note that ~/ will expand to the shell or post shell home and not the necessarily the termux home if used inside scripts or the *-commands options.

It's the users responsibility to properly quote all arguments passed to command options and also for any values like paths passed inside the arguments, specifically the *-commands and *-options options, so that whitespace splitting does not occur.

Check Arguments and Result Data Limits for details on the max size of arguments that you can pass to sudo script, specifically the size of core_script and its arguments for the script command type.

Shell Home

The default $HOME directory for sudo shell and sudo post shell is /data/data/com.termux/files/home/.suroot. The --shell-home and --post-shell-home options or the exported environmental variables $SUDO_SHELL_HOME and $SUDO_POST_SHELL_HOME can be used to change the default directory. The home directory should ideally be different from the termux home directory to keep config, rc and history files separate for the root user and the termux user. The home directory should also be owned by the root user and have 0700 permission so that non-root users cannot access it for security reasons and hence termux home should ideally not be used.

Check the Modifying Default Values section for more info on sudo environmental variables and modifying default values.

If the home directory is under the termux files directory, then it must not be one of the following directories: ~/.{cache,config,local,termux} and $PREFIX/*.

The home directory is automatically created when sudo command is run if it does not exist. The root:root ownership and 700 permission is also set to it.

If the home or working directories are in android rootfs / partition or android system /system partition, then the respective partition is automatically remounted as rw in the Global namespace when sudo command is run and remounted back to ro before sudo command exits, but only if the partition was mounted as ro before sudo command was run or --no-remount-ro was not passed. The --force-remount-ro option can be passed to force remounting to ro regardless of partition mount state before sudo command was run. For android >= 10, do not set home or working directory in rootfs or system partition since sudo script will exit with error. In android >= 10, rootfs partition is likely a read-only system-as-root SAR partition and system partition is likely an ext4 dedup filesystem which cannot be remounted as rw.

If the -E option is passed or an exec is manually done, then remounting back to ro will not happen.

Shell RC Files

The following shell rc files are used for different shells depending on if sudo shell or sudo post shell home is different from termux home or shared. The rc files are usually unique for different shells.

For shells that do not have rc files have their columns set to -.

ShellRCFILE (different home)RCFILE (shared home)Set Method
bash.bashrc.sudo_bashrc--rcfile
zsh.zshrc(shared)$ZDOTDIR
dash.dashrc.sudo_dashrc$ENV
sh.shrc.sudo_shrc$ENV
fish.config/fish/config.fish(shared)$XDG_CONFIG_HOME
python.pythonrc.sudo_pythonrc$PYTHONSTARTUP
ruby.irbrc(shared)(hard-coded)
pry.pryrc(shared)(hard-coded)
node---
perl---
lua5.2---
lua5.3---
lua5.4---
phpphp.ini.sudo_php.ini-c
python2.python2rc.sudo_python2rc$PYTHONSTARTUP
ksh.kshrc.sudo_kshrc$ENV

The rc file parent directory is automatically created when sudo command is run if it does not exist. The root:root ownership and 700 permission is also set to it.

The rc file is automatically created when sudo command is run if it does not exist. The root:root ownership and 600 permission is also set to it.

The rc file parent directory and rc file will not be created automatically if -no-create-rc is passed.

Shell History Files

The following shell history files are used for different shells depending on if sudo shell or sudo post shell home is different from termux home or shared. The history files are usually unique for different shells.

For shells that do not have history files have their columns set to -. For shells whose history cannot be disabled have their Disable Method column set to (not possible).

For pry shell, the existing history will still be loaded, but new history will not be saved.

ShellHISTFILE (different home)HISTFILE (shared home)Set MethodDisable Method
bash.bash_history.sudo_bash_history$HISTFILEHISTFILE="/dev/null"
zsh.zsh_history.sudo_zsh_history$HISTFILEHISTFILE="/dev/null"
dash.dash_history.sudo_dash_history$HISTFILEHISTFILE="/dev/null"
sh.sh_history.sudo_sh_history$HISTFILEHISTFILE="/dev/null"
fish.local/share/fish/fish_history.local/share/fish/sudo_fish_history$fish_history--private
python.python_history(shared)(hard-coded)readline.write_history_file = *None
ruby.irb_history(shared)(hard-coded)(not possible)
pry.pry_history(shared)(hard-coded)Pry.config.history_save = false
node.node_history.sudo_node_history$NODE_REPL_HISTORYNODE_REPL_HISTORY=""
perl.perl_history.sudo_perl_historyrlwrap --history-filename--history-filename "/dev/null"
lua5.2----
lua5.3----
lua5.4----
php.php_history(shared)(hard-coded)(not possible)
python2----
ksh.ksh_history.sudo_ksh_history$HISTFILEHISTFILE="/dev/null"

The history file parent directory is automatically created when sudo command is run if it does not exist. The root:root ownership and 700 permission is also set to it.

The history file is automatically created when sudo command is run if it does not exist. The root:root ownership and 600 permission is also set to it.

The history file parent directory and history file will not be created automatically if -no-create-hist or --no-hist is passed.

Modifying Default Values

Check the sudo.config file to see the environmental variables that can be used to change the default values. If the sudo.config file exits at ~/.config/sudo/sudo.config, then sudo will automatically source it whenever it is run. It must have termux user ownership or be readable by it.

You can download it from the master branch and set it up by running the following commands. If you are on an older version, you may want to extract it from its release instead.

config_directory="/data/data/com.termux/files/home/.config/sudo"
mkdir -p "$config_directory" && \
chmod 700 -R "$config_directory" && \
curl -L 'https://github.com/agnostic-apollo/sudo/raw/master/sudo.config' -o "$config_directory/sudo.config" && \
chmod 600 "$config_directory/sudo.config"

You can use shell based text editors like nano, vim or emacs to modify the sudo.config file.

nano "/data/data/com.termux/files/home/.config/sudo/sudo.config"

You can also use GUI based text editor android apps that support SAF. Termux provides a Storage Access Framework (SAF) file provider to allow other apps to access its ~/ home directory. However, the $PREFIX/ directory is not accessible to other apps. The QuickEdit or QuickEdit Pro app does support SAF and can handle large files without crashing, however, it is closed source and its pro version without ads is paid. You can also use Acode editor or Turbo Editor if you want an open source app.

Note that the android default SAF Document file picker may not support hidden file or directories like ~/.config which start with a dot ., so if you try to use it to open files for a text editor app, then that directory will not show. You can instead create a symlink for ~/.config at ~/config_sym so that it is shown. Use ln -s "/data/data/com.termux/files/home/.config" "/data/data/com.termux/files/home/config_sym" to create it.

If you use the bash shell in termux terminal session, you can optionally export the environmental variables like $SUDO_SHELL_HOME and $SUDO_POST_SHELL_HOME in the ~/.bashrc file by adding export SUDO_SHELL_HOME="/path/to/home" and export SUDO_POST_SHELL_HOME="/path/to/home" lines to it so that they are automatically set whenever you start a terminal session. However, the ~/.bashrc and rc files of other shells will not be sourced if you are running commands from Termux:Tasker or RUN_COMMAND Intent, and so it is advisable to use the sudo.config file instead, which will be sourced in all cases, regardless of how sudo is run.

Note that $SUDO_SHELL_PS1 and $SUDO_POST_SHELL_PS1 values will not work if $PS1 variable is overridden in rc files in $PREFIX/etc/ or in sudo shell and sudo post shell homes. Check RC File Variables section for more details.

Examples

If you are using a foreground terminal session, then you must disable the bash command completion and history expansion for the current terminal session before running sudo commands to pass multi-line arguments by running bind 'set disable-completion on'; set +H. Otherwise bash will try to auto complete commands and search the history, and you will get prompts like Display all x possibilities? (y or n).

su

sudo su

sudo --shell=python --work-dir="~/" su

sudo --shell-home="/.suroot" --no-remount-ro su

sudo -LP --shell-home="/.suroot" --work-dir='~/' su

sudo --no-hist --export-paths="/path/to/dir1:/path/to/dir2" --shell-options="--noprofile --init-file \"path/to/file\"" --shell-pre-commands='export VARIABLE_1="VARIABLE_VALUE_1"; export VARIABLE_2="VARIABLE_VALUE_2"; /path/to/script;' su

asu

sudo asu

path

sudo top -m 10 -n 1

sudo ps -ef

sudo dumpsys

sudo dumpsys | grep termux

script

bash
sudo -s 'echo "Hi, $1 $2."' "bash" "shell"

sudo -si 'echo "Hi, $1 $2."' "bash" "shell"

sudo -sif --keep-temp --script-name="sudo_test" --title="sudo_test" 'echo "Hi, $1 $2."' "bash" "shell"

sudo -siF '~/.termux/tasker/termux_tasker_basic_bash_test' "bash" "shell"

sudo -s --shell-pre-commands='
export VARIABLE_1="VARIABLE_VALUE_1"
export VARIABLE_2="VARIABLE_VALUE_2"
' '
echo "Hi, $1 $2."
echo "VARIABLE_1=\`$VARIABLE_1\`"
echo "VARIABLE_2=\`$VARIABLE_2\`"
' "bash" "shell"

sudo -sil --post-shell="python" --shell-pre-commands='echo "Running script"' --shell-post-commands='echo "Script complete\nGoing to launcher"' --shell-pre-commands='echo "Starting interactive python shell"' 'echo "Hi, $1 $2."' "bash" "shell"

sudo -s --shell=bash <(cat <<'SUDO_EOF'
echo 'What is your name?'
read name
echo "Hi, $name."
SUDO_EOF
)

sudo -s --shell=bash '
echo "What is your name?"
read name
echo "Hi, $name."
'

sudo -s --shell=bash '
echo '\''What is your name?'\''
read name
echo "Hi, $name."
'

sudo -sie --shell=bash <(cat <<'SUDO_EOF'
#if parameter count is not 2
if [ $# -ne 2 ]; then
    echo "Invalid parameter count '$#' to 'termux_tasker_basic_bash_test'" 1>&2
    echo "$*" 1>&2
    exit 1
fi

echo "\$1=\`$1\`"
echo "\$2=\`$2\`"

exit 0
SUDO_EOF
) "hello," "termux!"

sudo -so 'echo stdout; echo stderr 1>&2'

  

zsh
sudo -s --shell=zsh <(cat <<'SUDO_EOF'
echo "Hi, $1 $2."
SUDO_EOF
) "zsh" "shell"

sudo -s --shell=zsh <(cat <<'SUDO_EOF'
echo "What is your name?"
read name
echo "Hi, $name."
SUDO_EOF
)

  

fish
sudo -s --shell=fish <(cat <<'SUDO_EOF'
echo "Hi, $argv[1] $argv[2]."
SUDO_EOF
) "fish" "shell"

sudo -s --shell=fish <(cat <<'SUDO_EOF'
echo "What is your name?"
read -p "" name
echo "Hi, $name."
SUDO_EOF
)

  

python

Currently, python refers to python3 and python2 refers to python2 in termux. Check Termux Python Wiki for more information.

sudo -s --shell=python <(cat <<'SUDO_EOF'
import sys
print("Hi, %s %s." % (sys.argv[1], sys.argv[2]))
SUDO_EOF
) "python" "shell"

sudo -s --shell=python <(cat <<'SUDO_EOF'
name = input("What is your name?\n")
print("Hi, %s." % name)
SUDO_EOF
)

 

The following "tests" are in solidarity with the youtube-dl devs, EFF and the current Github response of the "incident".

The youtube-dl file is actually not a single python script text file but is a binary file containing multiple python files.

sudo -s --shell=python --script-name="youtube-dl" <(cat "$PREFIX/bin/youtube-dl") --help

sudo -sF --shell=python '$PREFIX/bin/youtube-dl' --help

sudo -s --shell=python "$(cat "$PREFIX/bin/bandcamp-dl")" --help

sudo -s --script-decode --shell=python "$(cat "$PREFIX/bin/bandcamp-dl" | base64)" --help

  

ruby
sudo -s --shell=ruby <(cat <<'SUDO_EOF'
puts "Hi, " + ARGV[0] + " " + ARGV[1] + "."
SUDO_EOF
) "ruby" "shell"

sudo -s --shell=ruby <(cat <<'SUDO_EOF'
puts "What is your name?"
name = STDIN.gets
name = '' if name.nil?
puts "Hi, " + name.chomp.to_s + "."
SUDO_EOF
)

  

node
sudo -s --shell=node <(cat <<'SUDO_EOF'
console.log(`Hi, ${process.argv[2]} ${process.argv[3]}.`)
SUDO_EOF
) "node" "shell"

sudo -s --shell=node <(cat <<'SUDO_EOF'
const readline = require('readline').createInterface({
    input: process.stdin,
    output: process.stdout
})

readline.question(`What is your name?\n`, (name) => {
    console.log(`Hi, ${name}.`)
    readline.close()
})
SUDO_EOF
)

  

perl
sudo -s --shell=perl <(cat <<'SUDO_EOF'
print "Hi, ", $ARGV[0], " ", $ARGV[1], ".\n";
SUDO_EOF
) "perl" "shell"

sudo -s --shell=perl <(cat <<'SUDO_EOF'
print "What is your name?\n";
$name = <STDIN>;
chomp($name);
print "Hi, ", $name, ".\n";
SUDO_EOF
)

  

lua5.2
sudo -s --shell=lua5.2 <(cat <<'SUDO_EOF'
io.write('Hi, ', arg[1], ' ', arg[2], '.\n')
SUDO_EOF
) "lua5.2" "shell"

sudo -s --shell=lua5.2 <(cat <<'SUDO_EOF'
io.write('What is your name?\n')
local name = io.read()
io.write('Hi, ', name, '.\n')
SUDO_EOF
)

  

lua5.3
sudo -s --shell=lua5.3 <(cat <<'SUDO_EOF'
io.write('Hi, ', arg[1], ' ', arg[2], '.\n')
SUDO_EOF
) "lua5.3" "shell"

sudo -s --shell=lua5.3 <(cat <<'SUDO_EOF'
io.write('What is your name?\n')
local name = io.read()
io.write('Hi, ', name, '.\n')
SUDO_EOF
)

  

lua5.4
sudo -s --shell=lua5.4 <(cat <<'SUDO_EOF'
io.write('Hi, ', arg[1], ' ', arg[2], '.\n')
SUDO_EOF
) "lua5.4" "shell"

sudo -s --shell=lua5.4 <(cat <<'SUDO_EOF'
io.write('What is your name?\n')
local name = io.read()
io.write('Hi, ', name, '.\n')
SUDO_EOF
)

  

php
sudo -s --shell=php <(cat <<'SUDO_EOF'
<?php
echo "Hi, " . $argv[1] . " " . $argv[2] . ".\n";
SUDO_EOF
) "php" "shell"

sudo -s --shell=php <(cat <<'SUDO_EOF'
<?php
echo "What is your name?\n";
$name = readline();
echo "Hi, " . $name . ".\n";
SUDO_EOF
)

Templates

Tasker

Termux needs to be granted Storage permission to allow it to access /storage/emulated/0/Download directory, otherwise you will get permission denied errors while running commands.

Passing Arguments

The core_script or any other arguments passed for all the command types must be preserved in their original form and must be passed as is to sudo without any variable expansion or history expansion, etc.

This can be done in two ways, either using single quotes to surround the core_script and arguments or passing them with process substitution with a literal cat heredoc.  

If you are using Termux:Tasker plugin to run sudo commands, you would need to use single quotes to pass arguments, since it doesn't support process substitution. You would need to install Termux:Tasker version >= 0.5 since argument parsing is broken in older versions. Check the Passing Arguments Surrounded With Single Quotes section for more details. Check the Template 2 and Template 3 of the Termux Tasker Plugin Sudo Templates Task task for templates on how to use single quotes to pass arguments with Tasker. Basically, just set your script text to the %core_script variable with the Variable Set action and add any additional command options or arguments to the %arguments variable.
 

If you are using a foreground terminal session or scripts to run sudo commands, you can use single quotes to pass arguments or use process substitution. If you are using a foreground terminal session, then you must disable the bash command completion and history expansion for the current terminal session before running sudo command to pass multi-line arguments by running bind 'set disable-completion on'; set +H. Check the Passing Arguments Using Process Substitution section for more details. Check the Examples section for templates on how to use process substitution to pass arguments.  

If you are using RUN_COMMAND Intent to run sudo commands with Tasker using the TermuxCommand() function in Tasker Function action, you don't need to surround the core_script or arguments with single quotes, since arguments are split on a simple comma , instead. If your arguments themselves contain simple commas , (U+002C, &comma;, &#44;, comma), then you must replace them with the comma alternate character ‚ (#U+201A, &sbquo;, &#8218;, single low-9 quotation mark) for each argument separately before passing them to the intent action and would also need to pass the -r command option to sudo. Check the Passing Arguments Using RUN_COMMAND Intent section for more details. Check the Template 2 of the Termux RUN_COMMAND Intent Sudo Templates Task task for a template on how to replace commas in each argument separately with Tasker.  

If you are using RUN_COMMAND Intent to run sudo commands with Tasker or other apps using the am command, like using the Run Shell action in Tasker, you need to surround all your arguments, like the core_script and all other arguments with single quotes when passing them to the com.termux.RUN_COMMAND_ARGUMENTS string array extra after you have escaped all the single quotes in the final value, since otherwise it may result in incorrect quoting if the arguments themselves contain single quotes. However, due to the string array extra, the arguments are still split on a simple comma , so if your arguments themselves contain simple commas , (U+002C, &comma;, &#44;, comma), then you would also have to replace them with the comma alternate character ‚ (#U+201A, &sbquo;, &#8218;, single low-9 quotation mark) for each argument separately before passing them as the argument to the extra and would also need to pass the -r command option to sudo. Check the Passing Arguments Using RUN_COMMAND Intent section for more details. Check the Template 3 of the Termux RUN_COMMAND Intent Sudo Templates Task task for a template on how to replace commas in each argument separately and also escape single quotes in all the arguments with Tasker.  

Note that for RUN_COMMAND Intent, any arguments passed to any command options or the main arguments to sudo should also not be surrounded with single or double quotes to prevent whitespace splitting in the intent action, like done for usage with Termux:Tasker plugin since splitting will occur on simple comma characters instead. Check the Template 4 of the Termux RUN_COMMAND Intent Sudo Templates Task task for a template for this.   

Passing Arguments Surrounded With Single Quotes

Any argument surrounded with single quotes is considered a literal string and variable expansion is not done. However, if an argument itself contains single quotes, then they will need to be escaped properly. You can escape them by replacing all single quotes ' in an argument value with '\'' before passing the argument surrounded with single quotes. So an argument surrounded with single quotes that would have been passed like 'some arg with single quote ' in it' will be passed as 'some arg with single quote '\'' in it'. This is basically 3 parts 'some arg with single quote ', \' and ' in it' but when processed, it will be considered as one single argument with the value some arg with single quote ' in it that is passed to sudo.

For Tasker, you can use the Variable Search Replace action on an %argument variable to escape the single quotes. Set the Search field to one single quote ', and enable Replace Matches toggle, and set Replace With field to one single quote, followed by two backslashes, followed by two single quotes '\\''. The double backslash is to escape the backslash character itself.

Escaping single quotes while running commands in a foreground terminal session will be much harder if there are many single quotes, same would apply for double quote surrounded strings, so use process substitution instead, check below.

The format is the following

sudo -s '
<core_script>
' '[some arg1]' '[some arg2]'

  

Passing Arguments Using Process Substitution

Process Substitution can be used to pass the core_script and core_script_args for the script command type and to pass the command_args for the path command type when running sudo from a foreground terminal session or from a script.

The following is the format for passing core_script text.

sudo -s <(cat <<'SUDO_EOF'
<core_script>
SUDO_EOF
)

The following is the process substitution part

<(

)

Inside it there is a cat Here Document. The script text should start after a newline after the 'SUDO_EOF' part. You can type anything as script text other than SUDO_EOF which when read, ends the script. The ending SUDO_EOF should be alone on a separate line. The starting 'SUDO_EOF' is surrounded with single quotes so that script is considered a literal string and variable expansion, etc doesn't happen.

cat <<'SUDO_EOF'

SUDO_EOF

Basically any text you type inside the cat heredoc will be passed to the process substitution which will create a temporary file descriptor for it in /proc/self/fd/<n> and pass the path to sudo script so that it can read the argument text from it.

You can also read text from an existing script file using cat and pass that to sudo like the following

sudo -s <(cat "~/some-script")

  

Passing Arguments Using RUN_COMMAND Intent

To use RUN_COMMAND Intent that has arguments working properly, you need to install Termux version >= 0.100 and Tasker version >= 5.9.4.beta. However, leading and trailing whitespaces from arguments will be removed for Tasker version < 5.11.1.beta if you are using TermuxCommand() function, so its advisable to use a higher version or use am command instead.  

If you are using the am command, the format is am startservice --user 0 -n com.termux/com.termux.app.RunCommandService -a com.termux.RUN_COMMAND --es com.termux.RUN_COMMAND_PATH '<path>' --esa com.termux.RUN_COMMAND_ARGUMENTS '<one_or_more_args_seperated_with_commas>' --es com.termux.RUN_COMMAND_WORKDIR '/data/data/com.termux/files/home' --ez com.termux.RUN_COMMAND_BACKGROUND 'false'  

If you are using the TermuxCommand() function, the format is TermuxCommand(path,<one_or_more_args_seperated_with_commas>,workdir,background). The args can be of any count, each separated with a simple comma ,. The only condition is that in the list the first must be path and the last two must be workdir and background respectively.  

For both the --esa com.termux.RUN_COMMAND_ARGUMENTS string array extra and the TermuxCommand() function, if you want to pass an argument that itself contains a simple comma , (U+002C, &comma;, &#44;, comma), it must be escaped with a backslash \, so that the argument isn't split into multiple arguments. The only problem is that, the arguments received by the script being executed will contain \, instead of , since the reversal isn't done as described in the am command source while converting to a string array. Tasker uses the same method. There is also no way for the am command or the script to know whether \, was done to prevent arguments splitting or \, was a literal string naturally part of the argument.

// Split on commas unless they are preceeded by an escape.
// The escape character must be escaped for the string and
// again for the regex, thus four escape characters become one.
String[] strings = value.split("(?<!\\\\),");
intent.putExtra(key, strings);

 

sudo uses an alternative method to handle such conditions. If an argument contains a simple comma ,, then instead of escaping them with a backslash \,, replace all simple commas with the comma alternate character ‚ (#U+201A, &sbquo;, &#8218;, single low-9 quotation mark). This way argument splitting will not be done. You can pass the -r option to sudo which will then parse arguments as per RUN_COMMAND intent rules to replace all the comma alternate characters back to simple commas. It would be unlikely for the core_script or the arguments to naturally contain the comma alternate characters for this to be a problem. Even if they do, they might not be significant for any script logic. If they are, then you can set a different character that should be replaced, with the --comma-alternative option. The -r and --comma-alternative options should ideally be the first options passed so that sudo replaces the alternative comma characters from all arguments passed after the options.

For Tasker use the Variable Search Replace action on an %argument variable to replace the simple comma characters. Set the Search field to one simple comma ,, and enable Replace Matches toggle, and set Replace With field to %comma_alternative where the %comma_alternative variable must contain the comma alternate character ‚.

Issues

Automatic redirection of stderr to stdout in SuperSU

In SuperSU v2.82 for the script command type, if stdin is available like running su in an interactive shell like from a foreground terminal session, then it automatically redirects stderr of commands to stdout, specially affecting the --script-redirect and related command options. However, if commands are run in a non-interactive shell, in the background, like from Termux:Tasker plugin, then stdout and stderr streams behave normally and are separate. This can be confirmed by running (su -c 'echo 1 1>&2' 2>/dev/null) and (exec <&-; su -c 'echo 1 1>&2' 2>/dev/null) in a terminal session. In the former case, 1 is still printed on the screen even though stderr is redirected to /dev/null. The later case closes the stdin file descriptor which makes su assume its running non-interactively. Running (su -c 'echo 1 1>&2' 1>/dev/null) also suppresses printing since it redirects stdout to /dev/null instead. Running (bash -c 'echo 1 1>&2' 2>/dev/null) works normally. Reopening stdin with hacks, inside the su shell doesn't work either for a few reasons, including that stderr redirection to stdout starts happening again. This seems to be an issue of the libsuperuser itself or how the su binary handles streams internally and might not be solvable but if you have a solution that can be used to prevent automatic redirection, please report it.

This does not affect usage with Termux:Tasker in background mode. This does not apply to Magisk, at least the currently latest version v21.1. However, this may apply to other su implementation.   

su -c support

The sudo script requires the -c command option support by the su binary. The su that comes with the android studio avd does not support it. Other su implementations may not support it either.

Moreover, linux distros removed support for starting interactive shells with the su -c command. Check debian su manpage. The -c command option info specifies that The executed command will have no controlling terminal. This option cannot be used to execute interactive programs which need a controlling TTY.. For more info, check debian bug report #628843 and ubuntu CVE-2005-4890. However, this likely does not apply to android su implementations, at least does not apply for SuperSU and Magisk currently, so sudo should work fine, at least on those.

Worthy Of Note

RC File Variables

If you don't know what $PATH, $LD_LIBRARY_PATH and $PS1 variables or rc files are or don't care to find out, then just run the commands below so that sudo works properly, otherwise read the details below. Ignore No such file or directory errors when running the commands.

sed -i'' -E 's/^(PS1=.*)$/\(\[ -z "\$PS1" \] \|\| \[\[ "\$PS1" == '\''\\s-\\v\\\$ '\'' \]\]\) \&\& \1/' "/data/data/com.termux/files/usr/etc/bash.bashrc"
sed -i'' -E 's/^(PS1=.*)$/\(\[ -z "\$PS1" \] \|\| \[\[ "\$PS1" == '\''%m%# '\'' \]\]\) \&\& \1/' "/data/data/com.termux/files/usr/etc/zshrc"
su -c "rm \"/data/data/com.termux/files/home/.suroot/.bashrc\""

 

rc files, short for run commands, are shell specific files that are run or sourced whenever an interactive shell is started to define variables and functions etc.

Make sure in your rc files like ~/.suroot/.bashrc file for bash (where ~/.suroot is the sudo shell home), the $PATH, $LD_LIBRARY_PATH and $PS1 variables and any other variables exported by sudo are not overridden, otherwise the sudo commands will not work properly, since sudo exports its own custom variable values which will get overridden when rc files are sourced by any new shell started. You can run commands like sudo -v --dry-run --shell=bash su to see what variables are normally exported for a given shell by sudo.  

$PATH or $LD_LIBRARY_PATH

Check the PATH and LD_LIBRARY_PATH Priorities section for more info on what these variables are.

For the $PATH or $LD_LIBRARY_PATH variables, either remove their variable set lines completely or if necessary only append any required paths to the existing variable values like export PATH="$PATH:/dir1:/dir2" and export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/dir1:/dir2" instead of overriding them with export PATH="/dir1:/dir2" and export LD_LIBRARY_PATH="/dir1:/dir2" in your rc files.  

$PS1

The $PS1 variable, short for Prompt String 1, defines the characters you see at the start of the "line" when typing commands in shells running interactively like bash or zsh. For termux bash shell, this defaults to $ . For termux zsh shell, this defaults to % .

If you want to allow sudo to set its own default $PS1 value # or the one set with the $SUDO_SHELL_PS1 or $SUDO_POST_SHELL_PS1 variables in the sudo.config file, then make sure the $PS1 value is not overridden by the shell rc files, otherwise you will not be able to easily tell the difference between whether you are running a shell via sudo or normally as the termux user when you run commands like sudo su. You can however check the value of $SHLVL to see the nested shell level, run printenv | grep SHLVL.

  1. The rc files in $PREFIX/etc/ are sourced first whenever shells are started by sudo. The $PS1 value is set and exported by sudo before new shells are started, however, the value will get replaced if its overridden by the rc files when they are sourced during startup of the new shell.

    • bash shell currently uses the $PREFIX/etc/bash.bashrc file, in which it sets the default value of $PS1 to \$ or \[\e[0;32m\]\w\[\e[0m\] \[\e[0;97m\]\$\[\e[0m\] in recent versions. You need to replace the line PS1='\$ ' or PS1=<default> with the conditional ([[ -z "$PS1" ]] || [[ "$PS1" == '\s-\v\$ ' ]]) && PS1=<default> so that $PS1 is only set if its not already set or is set to the default value internally used by bash. You can run the command sed -i'' -E 's/^(PS1=.*)$/\(\[ -z "\$PS1" \] \|\| \[\[ "\$PS1" == '\''\\s-\\v\\\$ '\'' \]\]\) \&\& \1/' "/data/data/com.termux/files/usr/etc/bash.bashrc" to automatically do it or you can do it manually by running nano "/data/data/com.termux/files/usr/etc/bash.bashrc".

    • zsh shell currently uses the $PREFIX/etc/zshrc file, in which it sets the default value of $PS1 to %# . You need to replace the line PS1='%# ' or PS1=<default> with the conditional ([[ -z "$PS1" ]] || [[ "$PS1" == '%m%# ' ]]) && PS1=<default> so that $PS1 is only set if its not already set or is set to the default value internally used by zsh. You can run the command sed -i'' -E 's/^(PS1=.*)$/\(\[ -z "\$PS1" \] \|\| \[\[ "\$PS1" == '\''%m%# '\'' \]\]\) \&\& \1/' "/data/data/com.termux/files/usr/etc/zshrc" to automatically do it or you can do it manually by running nano "/data/data/com.termux/files/usr/etc/zshrc".

  2. The rc files in ~/.suroot (default sudo shell home) are also sourced afterwards whenever shells are started by sudo. They must also not override the $PS1 value. However, if you want to set a custom value in them for usage outside sudo, then you can add conditionals to override $PS1 only if its not already set or is set to the default termux value set by $PREFIX/etc/* rc files.

    • bash shell default rc file set by sudo is ~/.suroot/.bashrc. You can for example set $PS1 to £ by adding the line ([[ -z "$PS1" ]] || [[ "$PS1" == '\$ ' ]]) && PS1='£ ' to it, where '\$ ' is the default value for PS1 in $PREFIX/etc/bash.bashrc file.

    • zsh shell default rc file set by sudo is ~/.suroot/.zshrc. You can for example set $PS1 to £ by adding the line ([[ -z "$PS1" ]] || [[ "$PS1" == '%# ' ]]) && PS1='£ ' to it, where '%# ' is the default value for PS1 in $PREFIX/etc/zshrc file.

This will ensure that the exported $PS1 variables will not be overridden by rc files for bash and zsh. For other shells that may use the $PS1 variable, you can use similar conditionals in their rc files.  

termux-sudo by st42

If you were previously using termux-sudo by st42, then it would have automatically created the ~/.suroot/.bashrc file with entries like the following. You should either remove those lines if you haven't exported custom values yourself or remove the file entirely if you haven't made changes to it yourself.

export LD_LIBRARY_PATH=$PRE/usr/lib
export PATH=/data/data/com.termux/files/usr/bin:/data/data/com.termux/files/usr/bin/applets:/system/xbin:/system/bin
export PS1="# "

To remove the ~/.suroot/.bashrc file, run su -c "rm \"/data/data/com.termux/files/home/.suroot/.bashrc\"" command.

To edit the ~/.suroot/.bashrc file, run su -c "nano \"/data/data/com.termux/files/home/.suroot/.bashrc\"" command. Make changes as advised above, then press Ctrl+o and then Enter to save and Ctrl+x to exit. You can also open the file with a text editor app with root support like QuickEdit or QuickEdit Pro.   

Arguments and Result Data Limits

There are limits on the arguments size you can pass to commands or the full command string length that can be run, which is likely equal to 131072 bytes or 128KB for an android device defined by ARG_MAX but after subtracting shell environment size, etc, it will roughly be around 120-125KB but limits may vary for different android versions and kernels. You can check the limits for a given termux session by running true | xargs --show-limits. If you exceed the limit, you will get exceptions like Argument list too long. You can manually cross the limit by running something like $PREFIX/bin/echo "$(head -c 131072 < /dev/zero | tr '\0' 'a')" | tr -d 'a', use full path of echo, otherwise the echo shell built-in will be called to which the limit does not apply since exec is not done.

Moreover, exchanging data between Tasker and Termux:Tasker is done using Intents, like sending the command and receiving result of commands in %stdout and %stderr. However, android has limits on the size of actual data that can be sent through intents, it is roughly 500KB on android 7 but may be different for different android versions.

Basically, make sure any data/arguments you pass to sudo script directly on the shell or through scripts or using the Termux:Tasker plugin or RUN_COMMAND Intent intent is less than 120KB (or whatever you found) and any expected result sent back if using the Termux:Tasker plugin is less than 500KB, but best keep it as low as possible for greater portability. If you want to exchange an even larger data between tasker and termux, use physical files instead.

The argument data limits also apply for the RUN_COMMAND Intent intent.   

PATH and LD_LIBRARY_PATH Priorities

The word executable will be used henceforth for binaries, scripts and any other executable files.

Termux executables currently exist at /data/data/com.termux/files/usr/bin and /data/data/com.termux/files/usr/bin/applets Termux libraries exist at /data/data/com.termux/files/usr/lib.

Android executables normally exist at /system/bin and/or /system/xbin Android libraries exist at /system/lib and/or /system/lib64.

When sudo su commands is run, then the termux executables paths are prepended to android executables paths in the $PATH variable. The termux library paths are prepended to android library paths in the $LD_LIBRARY_PATH variable. This gives priority to termux paths.

When sudo asu commands is run, then the android executables paths are prepended to termux executables paths in the $PATH variable. The android library paths are prepended to termux library paths in the $LD_LIBRARY_PATH variable. This gives priority to android paths.

The $PATH variable sets the paths to search for executables when commands are executed. The $LD_LIBRARY_PATH variable sets the paths to search for libraries for dynamic linking required by the commands that are executed. The path that appears first in both the variables is searched first and if the required binary, executable or library is found, that is the one thats used without looking further.  

There are a few important things to consider when using sudo with termux.

A executable that you want to run may exist in both termux and android executable paths but you may want to run a specific one. If you want to run the termux one instead of the the android one then run sudo su command and then run the command to run the executable. If you want to run the android one instead of the the termux one then run sudo asu command and then run the command to run the executable. However in both cases, if you write the absolute path of the executable instead of just writing its basename, the executable at the path you wrote will be executed even if the other ones path exist before in the $PATH variable.

Another thing to consider is that dynamic library linking errors may occur when executables try to link to the wrong library. Executables should be linked with libraries they are compatible with and that define all the needed functions needed by the executable. Executables that exist in termux executable path should ideally be linked with libraries that exist in termux library path. Executables that exist in android executable path should ideally be linked with libraries that exist in android library path.

When an executable is run, the paths in the $LD_LIBRARY_PATH variable are searched for the library that is required and whichever matching library is found first is used, even if that library is not compatible with the executable. If the library is indeed incompatible a linking error occurs with errors that may include words like CANNOT LINK EXECUTABLE and cannot locate symbol some_symbol referenced by /lib.....

So if an executable in android executable path tries to link with a library in termux library paths to which it is incompatible with, then a linking error will occur. This is likely to happen with some executables including the android dumpsys or input binaries among others. A linking error may occur the other way around too, when a termux executable tries to link with libraries in android library path. To prevent these linking error from occurring in most situations, separate sudo su and sudo asu commands exist, which set the correct order of paths in the $PATH and $LD_LIBRARY_PATH variables so that normally termux executables are linked with termux libraries and android executables are linked with android libraries whenever either command is run.  

However, another way to automatically prioritize android libraries is by running the path command type with sudo <command>. If the command exists in the /system partition, then android library paths are prepended to termux library paths in the $LD_LIBRARY_PATH variable automatically. An absolute path is not needed to be passed for this to work as the $PATH_TO_EXPORT is automatically searched. This is helpful for situations when you are already in a sudo su shell and do not want to shift to the sudo asu shell or unset $LD_LIBRARY_PATH to run just one executable in android executables paths.

You can also use the tpath and apath functions if they are defined in the rc file of your interactive shell to shift priorities.

Normally sudo su will work fine without problem when dropping to sudo shell. But if you want to specifically run an executable in the android executable paths instead of the one in termux executable paths or are getting linking errors when running android executables with sudo su, then try using sudo asu and then running the required command or use sudo <command> or sudo -a <command>.

tpath and apath functions

For the shells bash zsh dash sh fish ksh, additional functions named tpath and apath are added to their rc files if the sudo script creates the rc files, they are not added otherwise. You can call these functions to set priorities from inside interactive shell sessions only when running sudo su, sudo asu or sudo -is <core_script commands, since they depend on some environmental variables set by the sudo script and are not hard-coded in case of future changes.

The tpath function will set priority to termux bin and library paths in $PATH and $LD_LIBRARY_PATH variables.

The apath function will set priority to android bin and library paths in $PATH and $LD_LIBRARY_PATH variables.

The functions allows the users to quickly switch priorities without having to switch between sudo su and sudo asu shells.

If you already have an existing rc file for your shell like ~/.suroot/.bashrc and want to add the functions to it. Just temporarily move (not copy) the file to somewhere else and run sudo su command with the optional --shell option, then copy the functions from the new rc file created by sudo to your old file, then remove the new file and move the old file back.

export and unset functions

For the fish shell, additional functions named export and unset are also added to the rc files if the sudo script creates its rc file, they are not added otherwise. The functions port the bash export var=value and unset var functionality respectively.

Tests

Check the sudo_tests script to run automated tests for the sudo script command types, options and shells. Usage instructions are inside the script. There are more examples for running sudo inside the sudo_tests script that can be used by users, although may not be too user friendly to view or understand.

FAQs And FUQs

Check FAQs_And_FUQs.md file for the Frequently Asked Questions(FAQs) and Frequently Unasked Questions(FUQs).

Changelog

Check CHANGELOG.md file for the Changelog.

Contributions

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Credits

Donations