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.

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• 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).

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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