From: Mike Cahill <mike.cahill@...>
Date: 2007-05-19T10:55:51+09:00
Subject: ssh / popen / stdin weirdness

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Sorry I can't figure out how to find the cause of this myself.  I'm sure =
there's some article somewhere I'm not finding.

on RHEL4 u3, ruby 1.8, create:

=3D=3D=3D
app.rb:=20

  my_pipe =3D IO.popen("ssh foreign-host 'cat filename')
  file_contents =3D my_pipe.read
  my_pipe.close

  inp =3D $stdin.read=20
  puts "returning " + inp

=3D=3D=3D=3D

Run this app from this host (call it ServerB):
ruby app.rb <<EOF
hi there
EOF

You get "returning hi there", as expected.

----
Now, from ServerA (public keys have been pushed), run:

ssh ServerB 'ruby app.rb' <<EOF
hi there
EOF

it fails, in that inp receives nothing from $stdin.
 ----

now, go back to app.rb, remove the first three lines so there's no call =
to IO.pipe.

run it again, it works.

why does $stdin get "moved" when the app is called remotely and opens a =
pipe?




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