How to pipe Scilab on Windows

I am trying to do simple piping with Scilab on Windows but it doesn't work neither in cmd.exe nor in PowerShell. I know I can pass commands to the interpreter as simple as echo %pi | scilex -nb -quit, but I want to pass and read data instead of not directly sending commands.

I am using mgetl with file descritor %io(1) to access standard input, but the returned value is an empty matrix:

>echo Hello, World! | scilex -nb -quit -e "mgetl(%io(1))"
 ans  =

    []

If I use type and a file, the same behavior happens. Here tmp has a line break, but that is irrelevant because the behavior is the same with or without it:

>type tmp
Hello, 
World!

>type tmp | scilex -nb -quit -e "mgetl(%io(1))"
 ans  =

    []

However, by removing the left-hand side of the pipe and keeping %io(1) makes Scilab wait for user input until return then Ctrl+C is pressed:

>scilex -nb -quit -e "mgetl(%io(1))"
Hello, World!
 ans  =

  "Hello, World!"

Using fd=mopen('tmp'); mgetl(fd), mclose(fd); as the expression argument works, as expected, but that's not what I want, because it depends on a saved file. I want to read data directly from the output of another process by using | in cmd.exe or PowerShell. What is wrong with this approach? Is this an unexpected behavior?

Solution

It seems that you cannot read stdin with mgetl, but with read which uses Fortran formats, it works

C:\>echo Hello, World! | scilex -nb -e "read(%io(1),1,1,'(a)')"
 ans  =

  "Hello, World! "


C:\>

The fact that mgetl cannot read from stdin is a bug that will be fixed in the upcoming release of Scilab (6.1.1) : http://codereview.scilab.org/#/c/21778, thanks for reporting.