Exec`ing external programs

[Grant Edwards]

In article <uu0e96366cek50 at corp.supernews.com>, adrian at twistedliving.com wrote:

> import os,sys
> 
> a = open('host_list', 'r')
> for host in a.readlines():
> 	os.system('xterm -e atl.py %h &',%(host))
> 
> What I`m trying to do is read a list of hostnames and for each one
> open an xterm and exec atl.py with host as an argument. I am unable
> to background the job, so It hangs until I close the first window.

My guess: Each of the strings returned by readlines contains a newline at
the end. The shell sees that newline (which is before the ampersand) and
runs the command in the foreground.

> However if I set a to a list of hostnames inside the script, it 
> functions correctly, but fails when reading from a file.

Here's a hint: Since you know it works when 'a' is a hand-coded list of
strings, and fails when a.readline() is used, take a careful look at the
difference between the 'host' values in the two cases.

-- 
Grant Edwards                   grante             Yow!  Are you guys lined up
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