os.execv Overhead

[mark.mcdowall]

I have a script that automates running a program X times by preparing
the required files and passing the external program right variables.

What I am unsure about though is the overhead of:

program = "externalScript"
variables = ["-i", "var1"]
pid = os.fork()
if not pid:
os.execv(program, [program] + variables)
os.wait()

Whether there would be a more efficient way of making such a call.

Any comments would be greatfully appreciated.

 

[Jim Wilson]

overhead of [fork/exec]:

An alternative might be os.spawn?(), etal. It might run a tiny bit faster
because it combines the two operations, but I think you're pretty close to the
metal.

Jim

 

[Nobody]

I have a script that automates running a program X times by preparing
the required files and passing the external program right variables.

What I am unsure about though is the overhead of:

program = "externalScript"
variables = ["-i", "var1"]
pid = os.fork()
if not pid:
os.execv(program, [program] + variables)
os.wait()

Whether there would be a more efficient way of making such a call.

I would expect the overhead to be dominated by the underlying fork() and
execve() system calls, rather than anything within Python.

OTOH, using subprocess.call() wouldn't be any slower, and is more portable.