what do you mean here by 'owns' the terminal ? and that in the second (subshell) example none of these things is true. in '(command)' is command attached to the terminal and in '<(command)' command is not?
On Tue, May 19, 2015 at 8:42 AM, Pierre Gaston <pierre.gas...@gmail.com> wrote: > > > On Mon, May 18, 2015 at 10:26 PM, Chet Ramey <chet.ra...@case.edu> wrote: > >> On 5/16/15 1:11 PM, marz...@gmail.com wrote: >> >> > Bash Version: 4.3 >> > Patch Level: 30 >> > Release Status: release >> > >> > Description: >> > from interactive shell running cat < <(read -r var) prints: >> > bash: read: read error: 0: Input/output error >> > >> > on the other hand: >> > (read -r var) reads chars from terminal stdin >> > >> > >> > Repeat-By: >> > cat < <(read var) >> >> I'm not sure what the question is here. The two constructs are totally >> different in effect and implementation. The error comes because the >> process substitution is run asynchronously, in the same process group as >> the calling shell (though exactly which pgrp doesn't matter), and the >> `cat' process runs in a different process group and `owns' the terminal. >> >> In the second (subshell) example, none of these things is true. >> >> -- >> ``The lyf so short, the craft so long to lerne.'' - Chaucer >> ``Ars longa, vita brevis'' - Hippocrates >> Chet Ramey, ITS, CWRU c...@case.edu >> http://cnswww.cns.cwru.edu/~chet/ >> >> The question really is (I discussed this with him on IRC) why can you do: > > $ cat <(read var </dev/tty;echo $var) > blah > blah > > but not: > > $ cat < <(read var </dev/tty;echo $var) > bash: read: read error: 0: Input/output error > > > >
