2018-05-27 19:26 GMT+02:00 Thomas Danckaert <p...@thomasdanckaert.be>:
> From: Stefan Israelsson Tampe <stefan.ita...@gmail.com> > Subject: Re: capture stdout and stderr > Date: Thu, 24 May 2018 15:25:51 +0200 > > I think that your code whould work but doesn't because string ports are >> not file ports and system commands pipes out to file ports. >> >> 'open-input-pipe' uses 'scm_open_process' that returns only a read-port >> and a write-port, the write port is then taped the output string in your >> run-command. >> and it works. >> >> ALso when you create a err-port with pipe, you create a file port nad >> this will be used translated as an error port for the system comand and it >> all works. >> However the failing program uses a string port which is not a file port >> and it does not end up capturing the error output in the system command. >> >> One would wish that guile if the error port is not a file port make a >> file port, as done with 'pipe' and create a thread that pipes the data from >> the file port to the non file port and your code >> would work. Also similarly behavior for read and write ports towards the >> shell. >> >> the relevant code is in posix.c, scm_open_process >> > > Hi! Thanks for the message. Indeed, that makes sense. In fact I had some > vague intuition that some magic would be needed to channel the stderr > output into such a string port. I think the manual could be more explicit > about that, though? (e.g. in the section on default ports > https://www.gnu.org/software/guile/manual/html_node/Default- > Ports.html#Default-Ports ). Maybe I should propose a patch to the docs, > stating that those "with-x-to-port" methods only work on file ports. > > Thomas > > > Thomas thank you for sharing the solution
