When issuing commands like "exec dir" or an "exec echo Hello World", the following error occurs:
When attempting to execute an application, exec first searches for the name as it was specified.
Then, in order, .com, .exe, and .bat are appended to the end of the specified name and it searches for the longer name.
The user should ensure that the command "executable" being executed is in the system PATH, or provide the complete path to the executable within the exec command.
In Windows, in order to execute the shell built-in commands like dir and copy, the caller must prepend ``cmd.exe /c '' to the desired command.
Optionally, in the Vivado Tcl console, a user might issue the dir and echo commands by themselves without the exec command as a precursor.
When the Vivado Tcl shell does not recognize these commands, it will automatically pass them to the OS shell.