NAME

appscript — Very lightweight script to create self-extractable archives

SYNOPSIS

DESCRIPTION

appscript is a very lightweight script that compresses a directory using tar(1), encodes the result with base64(1), and then creates a sh(1) script that decompresses that result into a temporary location (optionally using tmpfs(4)), and finally executes a script named APPSCRIPT from the current working directory.

The resulting script handles signals generated by certain events to clean up the temporary location created, including unmounting the mounted tmpfs(4) filesystem if the script is configured to do so.

The idea is similar to how makeself(1) works, but it is written entirely in POSIX shell, leveraging tmpfs(4), and is much lighter. appscript has been implemented in fewer than 160 lines, and the resulting script has fewer than 60 lines. Unlike makeself(1), which aims to implement more use cases and emulate the behavior of some file archiving utilities that create executables, appscript only aims to run a script with all dependencies contained within it. In this context, “dependencies” refers to the files the script wants to use. You can combine appscript with appjail(1) to run applications (possibly with appjail-x11(1)) in an isolated and disposable manner. From the user’s perspective, it’s like running an application with a single click.

-L

All symbolic links will be followed.
Normally, symbolic links are archived as such. With this option, the target of the link will be archived instead.

-v

Display version information about appscript.

-t

Configure the resulting script to use tmpfs(4) when vfs.usermount is set to 1. If the attempt to mount tmpfs(4) fails, the resulting script will continue regardless.

-c [gzip|xz|zstd]

Compression algorithm to be used. xz is the default.

-o filename

Name of the resulting script. By default, /dev/stdout.

The execute bit is always set if this argument is a file.

directory

Directory to be compressed.

appscript assumes that the APPSCRIPT script is already present and has the execute bit set.

ENVIRONMENT

APPSCRIPT_PWD

Since APPSCRIPT runs from the current user's working directory, it does not know the location of the temporary directory. This environment variable specifies that location.

APPSCRIPT_SCRIPT

Absolute path to the AppScript that is currently running.

SEE ALSO

appjail(1) tar(1) base64(1)

AUTHORS

Jesús Daniel Colmenares Oviedo <DtxdF@disroot.org>