/k24-project1-2022

multi-process system designed to process text files, identify HTTP URLs, extract their locations, and record the results in an output file. The system consists of a manager process that coordinates with worker processes to handle file processing tasks.

Primary LanguageC++

k24-project1-2022

Anna Googula

Purpose: Creating processes using the fork/exec system calls, interprocess communication through pipes and named pipes, using low-level I/O, handling signals, and creating a shell script.

  • manager/ manager.cpp:
    • he is taking as an input a string, that contains the filename. We separate the file name. (The manager doesn't want to find the available workers, he just makes a new worker every time!) Making a new worker (initially, the manager is making workers/childs)
      1. we make a name for the pipe
      2. creating a named pipe/ fifo.
      3. push in the queue the worker and the pipename (we use it for the available workers).
      4. exec the child-manager
      5. we open the pipe from the parent side so that the manager can send the file name to the worker (with the pipe).
    • When the manager wants to stop the program, we close the fifos, pop the deqeus.
  • manager.h:
    • function manager_messege: takes the fifoname and he is writing to the pipe
  • workers/ workers.cpp:
    • The worker opens the pipe and waits to read from the manager.
      1. We make a .out file for the filename that the worker reads,
      2. open the file and reads bytes to bytes. We separate every word we read and if we find a string that matched the "http://" string we keep it
      3. Now we parse the URL when we find a "/". The second string is the one that we want. We save it. (I did not separate the www. from the urls...)
      4. We write to the file_name.out the "domains" (without the times we found it in the file...).
      5. close the file we were reading, close the .out file and When it's stops send a signal to the parent!
  • listener: it's a child (pid) of manager process. Just executing (/calling) the inotifywait to keep an eye on the current directory (we putting the new files here).

Further observations

  • finder.sh: sniffer doesn't output the "location num_of_appearances" but the finder can find the numbers for the TLDs (if we put a right file :)).

  • the pipes are open until the end.

  • Makefile is not working :) You can do this instead:

    • g++ -g -Wall manager.cpp -o sniffer
    • g++ -g -Wall workers.cpp -o workers
    • ./sniffer