use a string as stdin?

[Valerio Schiavoni <valerio.schiavoni@...>]

hello,
i execute a command-line program via popen. This command can receive
input from stdin or from a file.
The input parameter in my case is a string. Currently, I wrote the
string on a temp file, and I specify the name
of the file as a parameter to the command given to popen.

Do you know if it's possible to play with stdin so that the string is
set as the current stdin, so that I avoid to write on disk ?

Thanks,
valerio