En Sun, 30 Aug 2009 17:25:40 -0300, Chris Rebert <c...@rebertia.com>
escribió:
On Sun, Aug 30, 2009 at 12:33 PM, Sebastian<seb...@gmail.com> wrote:
Hello World!
This is my first post on the list and I'm hoping it is the right forum
and
not OT, I've searched
a bit on this, but, none-the-wiser!
My question is on the Popen method, here is my snippet:
p1 = Popen(["cat", "georgi_ddr7_allmag_kcor_in_test.dat"], stdout=PIPE
)
p2 = Popen(["fit_coeffs"], stdin=p1.stdout, stdout=PIPE)
p3 = Popen(["reconstruct_maggies"], stdin=p2.stdout,stdout=PIPE)
output_maggies_z=p3.communicate()[0]
p1 = Popen(["cat", "georgi_ddr7_allmag_kcor_in_test.dat"], stdout=PIPE
)
p2 = Popen(["fit_coeffs"], stdin=p1.stdout, stdout=PIPE)
p4 = Popen(["reconstruct_maggies", "--band-shift", "0.1", "--redshift",
"0."], stdin=p2.stdout,stdout=PIPE)
output_maggies_z0=p4.communicate()[0]
That is, p1 and p2 are the same, but p3 and p4 which they are passed
to, are
different.
Is there a way to pass p1 and p2 to p3 AND p4 simultaneously, so as to
not
need to
run p1 and p2 twice, as above?
What arguments would I need to achieve this?
NOTE: "georgi_ddr7_allmag_kcor_in_test.dat" is a very large file (~1E6
records)
Send the output of p2 through the unix command "tee"
(http://unixhelp.ed.ac.uk/CGI/man-cgi?tee). Then put the output of tee
into p3 and set p4's input to the file you specified to tee.
In addition to that, you can avoid the cat command (and omit p1
completely), just pass the georgi file as p2 stdin:
p2 = Popen(["fit_coeffs"], stdin=open("georgi..."), ...
In other words, the original shell commands are:
cat georgi.dat | fit | reconstruct
cat georgi.dat | fit | reconstruct --otherargs
and we suggest doing:
fit < georgi.dat | tee /tmp/foo | reconstruct
reconstruct --otherargs < /tmp/foo
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
