How to use start command in bash on Windows

Question

I want to use Windows' start command in bash on Ubuntu on Windows (i.e., WSL). However, I couldn't use it by simply typing start:

nek@NEK:/mnt/c/Users/Nek$ start test.txt
Command 'start' is available in '/sbin/start'
The command could not be located because '/sbin' is not included in the PATH environment variable.
This is most likely caused by the lack of administrative privileges associated with your user account.
start: command not found

And I noticed that start.exe might not exist.

C:\Users\Nek>where start
INFO: Could not find files for the given pattern(s).

Is start a builtin command? Can we use start in bash?

Environment

• Windows 10 build 14393.693 (Update: This version is old for executing .exe files on bash. I should update Windows build >= 14951, and then follow the answer.)
• Bash on Ubuntu on Windows (bash 4.3.11(1)-release x86_64-pc-linux-gnu, Ubuntu 14.04)

Related Links

• "How can I “open” a file from WSL with the default application?" -- superuser
• "Interop between Windows and Bash" -- Windows Command Line Tools For Developers

Answer 1

Is start a builtin command?

Yes.

Internal commands

The Windows CMD shell CMD.exe contains a number of 'internal' commands, additional 'external' commands are also supplied as separate executable files. External commands are generally stored in the C:\WINDOWS\System32 folder, this folder is part of the system PATH .

This arrangement means that both internal and external commands are always available no matter what your current directory happens to be.

ASSOC, BREAK, CALL ,CD/CHDIR, CLS, COLOR, COPY, DATE, DEL, DIR, DPATH, ECHO, ENDLOCAL, ERASE, EXIT, FOR, FTYPE, GOTO, IF, KEYS, MD/MKDIR, MKLINK (vista and above), MOVE, PATH, PAUSE, POPD, PROMPT, PUSHD, REM, REN/RENAME, RD/RMDIR, SET, SETLOCAL, SHIFT, START, TIME, TITLE, TYPE, VER, VERIFY, VOL

Source syntax-internal

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Can we use start in bash?

Yes. Start a command shell and run the start command.

Example:

cmd.exe /c start "" test.txt

If this doesn't work specify the full path as follows:

/mnt/c/Windows/system32/cmd.exe /c start "" test.txt

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Further Reading

• An A-Z Index of the Windows CMD command line - An excellent reference for all things Windows cmd line related.
• cmd - Start a new CMD shell and (optionally) run a command/executable program.
• start - Start a program, command or batch script (opens in a new window).

Answer 2

In other answers, cmd.exe is suggested. However, the Command Prompt does not support UNC paths. The Linux file system in WSL2 is represented as UNC paths in Windows.

In this case, the better alternative is PowerShell. Borrowing from Alex G's function, it is re-written as:

function start {
  abspath=$(readlink -f "$1");
  wpath=$(/bin/wslpath -w "$abspath");
  powershell.exe -Command Start-Process "$wpath"
}

If you have disabled the addition of Windows PATH by adding [interop] appendWindowsPath = false to /etc/wsl.conf, then use the absolute path gotten by where powershell.exe:

function start {
  abspath=$(readlink -f "$1");
  wpath=$(/bin/wslpath -w "$abspath");
  /mnt/c/WINDOWS/System32/WindowsPowerShell/v1.0//powershell.exe -Command Start-Process "$wpath"
}

Add this to your .bashrc to make sure you have it in every session.

Usage:

• start . - Opens the current directory in Windows File Explorer.
• start /any/linux/path - Opens the Linux directory as a UNC path.
• start /mnt/c/any/windows/path - Opens the Windows folder as a regular path.
• start - Forces the PowerShell command to prompt you for a path. Type one in, such as . or a Windows/UNC path (Linux paths won't work here) or press Ctrl-C to cancel.
  • Perhaps the function can be enhanced to take care of this edge case. I leave that to you as an exercise.

Answer 3

The above answer didn't work for me - cmd.exe is expecting a windows path (C:\this\that) rather than a linux path. The following shell function got me up and running:

function start {
    abspath=$(readlink -f "$1");
    wpath=$(/bin/wslpath -w "$abspath");
    /c/Windows/System32/cmd.exe /c start "" "$wpath"
}