How to schedule system calls with Python
Jorgen Grahn
grahn+nntp at snipabacken.se
Wed Oct 21 18:01:05 EDT 2009
On Thu, 2009-10-15, TerryP wrote:
...
> launching external programs, irregardless of language, generally falls
> into 3 major categories:
>
> 0.) blocks until program is done; like system
> 1.) replaces your program with process, never returns; like exec
> 2.) quickly return after asynchronously launching the program
>
> Most languages will implement the first method because of the standard
> system() function in C, which is fairly popular in it's own right.
> Most multi-tasking operating systems will implement some form of exec
> function, which Python exposes through the os module. The last method
> is the least portable, because obviously if the OS lacks multi-tasking
> you're screwed. The best examples of 2. are the UNIX popen() function
> and Microsoft's spawn() family, when used with the P_DETACH flag.
Not sure that popen() fits nicely into that category -- you have to
eat the child's output or feed it with input, or it will eventually
stall.
> Python being made with much loving kindless, exposes each interface.
Nicely put!
/Jorgen
--
// Jorgen Grahn <grahn@ Oo o. . .
\X/ snipabacken.se> O o .
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