SImilarities between exec and os.system() [closed] - python

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 8 years ago.
Improve this question
I am new to multi-threaded programming in python.
Can someone tell me whether os.system("ls") in python and exec("ls") call in "C" are doing the same ?
Please tell me about the similarities and dissimilarities as well.

In C, exec(whatever) replaces the current process's code with the code from whatever. Thus, it never returns. You can do the same in Python with os.execv and friends -- see https://docs.python.org/2/library/os.html#process-management .
os.system(whatever), on the other hands, forks the current process, execs whatever in the subprocess, waits for it to end, then returns. So, it's the same as system(whatever) is in C: a simple layer on top of fork, exec, and wait system calls (in Unix-like systems; simulated by other means in non-Unix-based systems, of which I believe the only one around in substantial numbers these days is Microsoft Windows).

Related

How to convert python code into a simple c haeder? [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 7 months ago.
Improve this question
I'm Working on a program that takes in text from the user and then implements functionalities in the backend, kind of like an interpreter, I have the parser working amazingly in python but some of the backend capabilities I feel would do great on c. I have looked into CPython but I don't seem to understand how to do it if it's even possible at all. I'm just a beginner, if someone could guide that will be very helpful.
CPython is just an implementation of Python in the C programming language. If you want to incorporate C code, you can write extension modules documented here.
Check out this StackOverflow post as well.
Alternatively, write a C program, compile it, and then call it via the subprocess module documented here.

How to verify it's the same computer [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 3 years ago.
Improve this question
I was wondering if there's any Python code I can run that, assuming the Python code has not been tampered with, will return an ID specific to that computer that cannot be spoofed. My initial thought was to use MAC addresses, but I know those can be easily spoofed. How about CPU serial number? How would I go about doing that?
Thanks.
This is an impossible problem, as it's equivalent to effective DRM. Every identifier can be spoofed. Remember, the user can tamper with your Python code (any compiling/obfuscating/encrypting you do can be reversed, so don't bother) to return whatever identifier they want. (And even if your code were absolutely read-only, they could change the Python runtime or the OS to do whatever they want.)

What is the difference between python function and python module [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 2 years ago.
Improve this question
I am a beginner of python i didn't found any difference between function and module.it is said that module stores code even after shutting the shell off rather than function.but when i tried to do so it didn't work for me.SO what is the big deal of using a module rather than function in the programming
In programming, function refers to a segment that groups code to perform a specific task.
A module is a software component or part of a program that contains one or more routines.
That means, functions are groups of code, and modules are groups of classes and functions.

hook file creation in python [closed]

Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 5 years ago.
Improve this question
I'm working on a program, where in some part of it, it needs to listen to the OP for when files are created/saved, so I can work on said file.
I know the basic concept of hooking, but I don't know exactly how to implement it in this specific use(I know how to attach a hook to a specific PID, but here I need to listen to all processes and see if one of them is creating a file).
I'm using pydbg for my hooking needs, but if your answer uses something different, feel free to still answer.
Thanks :)
It seems you need something like watchdog, pyinotify or python-inotify. You can also see this SO question for other options.

Python / package source code [closed]

Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 8 years ago.
Improve this question
When I ctrl click a builtin function in my IDE I noticed I usually get sended to an init file which holds the function but it just returns the function again.. It states a vague doc string like 'original footprint unknown'
Where do I find the real functions ?
For example where is print_function
the specific example, print is defined in C, in the bltinmodule.c: specifically.
http://hg.python.org/cpython/file/3.3/Python/bltinmodule.c#l1518
More generally, functions implemented in C have no equivalent to the source file you would read in python; the C code is compiled into binary machine code, and no reference to where that bit of code might have come from is (usually) retained in the result; and even if there was, it's unlikely that you happen to have the source code installed in a place your IDE is likely to find it, unless you built it yourself, with debug symbols, and are running the C executable process in that ide's debugger.
Usually in the same directory where that file is. (Which I can't possibly know.)

Categories

Resources