[[What is the purpose of this Windows environment variable and how does it impact Tcl?]]

[MHo]: COMSPEC holds the path to the current command processor (command shell), which is something like '''c:\windows\system32\cmd.exe''' on modern windows versions. On Windows 9.x, the command shell is '''command.com''' instead of '''cmd.exe''', which is a relict from 16 bit-MSDOS-days (still present for compatibility reasons). Programs could (and should) shell/exec to env(comspec) instead guessing what the command processor is ;-) I don't know how this environment variable is used by tcl internally...

[Duoas] The COMSPEC environment variable is used by the '''auto_execok''' command to find the command shell on Windows systems.

This environment variable can be found on other systems with varying levels of Windows emulation, but unless `$tcl_platform(platform) eq {windows}` it is not used, and is not guaranteed to be entirely uppercase. See the `~/lib/tclX.Y/init.tcl` startup script for details.

Oh yeah, almost forgot: Since Windows NT `command.com` is essentially an alias for `cmd.exe`. In any case, always use '''auto_execok''' to start a shell program. :-)
----
!!!!!!
%|[Category Windows]|%
!!!!!!