Launch Desktop Entries (or arbitrary commands) as Systemd user units, and do it fast.

Based heavily on mechanisms and optimizations introduced into xdg-terminal-exec by @fluvf, it performs function similar to (and behaves similarly to) uwsm's app subcommand, but without the costly startup of Python interpreter or the necessity of having a daemon running for speeding things up. If run on a fast shell (such as dash) with system stored on an SSD, overhead can be as short as ~0.03s, with systemd-run giving additional ~0.03s.

app2unit \
  [-h | --help]
  [-s a|b|s|custom.slice] \
  [-t scope|service] \
  [-a app_name | -u unit_id] \
  [-d description] \
  [-S out|err|both] \
  [-T] \
  [-O | --open] \
  [-c|-C] \
  [--fuzzel-compat] \
  [--test]
  [--] \
  {entry-id.desktop | entry-id.desktop:action-id | command} \
  [args ...]

See --help for more info.

Transparently, via having environment variables in your sessions:

To use UWSM's custom slices:

APP2UNIT_SLICES='a=app-graphical.slice b=background-graphical.slice s=session-graphical.slice'

To change default unit type:

APP2UNIT_TYPE=service

Can be integrated into Fuzzel launcher via its launch prefix feature: --launch-prefix='app2unit --fuzzel-compat --'. app2unit will use command line provided by Fuzzel as is, but currently it will have to re-find and re-parse desktop entry to extract metadata since Fuzzel can only tell it Desktop Entry ID and nothing more.

Requires xdg-terminal-exec. When the terminal is requested explicitly (with -T argument or *-term executable link), any unknown option starting with - after -T and before -- (or a command) are passed to xdg-terminal-exec to be handled according to the Default Terminal Spec proposal.

app2unit -T or app2unit-term (without command) can be used to open the default terminal as a unit, with unit metadata filled from its desktop entry.

Proper metadata support requires scripting options in xdg-terminal-exec available since version 0.13.0.

If invoked with -O | --open option, or if the executable's name ends with -open (i.e. via app2unit-open symlink), the script becomes an analog of xdg-open: files or URLs given in arguments are opened with a desktop entry automatically selected via xdg-mime. This can be a unit-aware drop-in replacement for xdg-open.

Assuming it is an association for inode/directory:

app2unit-open .

Links are available to pre-select some launching modes via a single command:

• app2unit-open
• app2unit-open-scope
• app2unit-open-service
• app2unit-term
• app2unit-term-scope
• app2unit-term-service

This may come in handy for situations where other apps can only operate a command without arguments. I.e., selecting a terminal command in PCmanFM.