Run a external program.

[Mark Tolonen]

"Yasser Almeida Hernández" <pedro.al at fenhi.uh.cu> wrote in message 
news:20091114142611.sj45qput2c84s0w0 at correo.fenhi.uh.cu...
> Hi all!!
>
> I'm writing a script where i call a external program which receive  some 
> arguments.
> One of this arguments is stored in a variable, that is passed as  argument 
> as well:
>
> import os
> ...
> f = open(file1, 'r')
> s = 'command $f -i file2 -w 1.4 -o file3.out'
> os.system(s)
> ...
>
> When i run the script i get the next message...
> '-i: No such file or directory'
> ... with a obvious error in the exit of the program. If i remove the 
> option -i i get the same error with every option, even with those who 
> don't get any file as argument. (file2 exist).
> BUT, when i run the external program in a python shell, it works...
>
> What's wrong?

Please post a small, complete example of your code and the error message. 
Cut-and-paste them exactly.  Also provide the shell command you are running 
that works.

-Mark