#OS and System Programming

Lab2:

  ./lab2.c file folder  

Find the file in the folder. The program is also searching in subfolders. If any file is found, then print info about it to the terminal.

Lab3:

  ./lab3.c folder1 folder2 N  

Compare folder1 with folder2. If there is no same ones in folder2, then make it (include subfolders).
Copying is used in N specialized processes, which return pid, filename, total number of bytes scanned, and comparison results.

Lab4:

  ./lab4.c

Make a group of processes and show the interaction between them through signals SIGUSR1 and SIGUSR2.
Tree of processes: 1->(2,3,4,5) 5->(6,7) 7->8
Where to send signal: 1->2 SIGUSR1 2->(3,4) SIGUSR2 4->5 SIGUSR1 3->6 SIGUSR1 6->7 SIGUSR1 7->8 SIGUSR2 8->1 SIGUSR2

Lab5:

  gcc … -lpthread 
  ./lab5.c folder1 folder2 N

Just the same, as Lab3, but instead of processes there are threads.

Lab6:

  gcc … -lpthread  
  ./Lab6.c filename1 filename2 N

The program is copying file filename1 in N processes at the same time in filename2. To copy, the input file is split into N parts and each part is copied in a separate process. To solve the problem of mutual exclusion while simultaneously writing to the output file, use a semaphore. The number of processes at any given time must be equal to N.

Lab7:

  gcc … -lpthread
  ./Lab7.c folder1 folder2 N

Just the same, as Lab3, but there you should ‘talk’ with ‘child’ process through pipelines. Each ‘child’ process is given info through a pipeline: file and where to copy and access rights to the file. Each ‘child’ should return his pid, filename and full size of the file.

Lab8:

  gcc … -lpthread  
  ./Lab8.c N n

Write a program to find the array of function values y[i]=sin(2 × PI × i / N) (i = 0,1,2...N-1) using Taylor series.
The program is split in 3 processes.
1 process: counting n Taylor series members of sin and transfer them to 2 process.
2 process: summation of Taylor series members of a particular sin and transfer the result to 3 process.
3 process: write results of calculations in a file.