parallel-programming/README.md

# parallel-programming

A collection of tasks for studying parallel programming

#### 1. Setup a proxy (on university computers only):

##### On Ubuntu:

```sh
echo 'http_proxy="http://212.192.128.4:8080/"' | sudo tee -a /etc/profile
echo 'https_proxy="http://212.192.128.4:8080/"' | sudo tee -a /etc/profile
```

Reboot a virtual machine to apply changes:

```sh
systemctl reboot
```

##### On Fedora:

```sh
echo 'proxy=212.192.128.4:8080' | sudo tee -a /etc/dnf/dnf.conf
echo 'http_proxy="http://212.192.128.4:8080/"' | sudo tee -a /etc/profile
echo 'http_proxy="http://212.192.128.4:8080/"' | sudo tee -a /etc/profile
```

Reboot a virtual machine to apply changes:

```sh
systemctl reboot
```

#### 2. Install a necessary dependencies:

##### On Ubuntu:

```sh
sudo apt install gcc g++ libomp-dev git
```

##### On Fedora:

```sh
sudo dnf install gcc gcc-c++ libgomp git
```

#### 3. Clone the repository:

```sh
git clone https://git.disroot.org/hassiy/parallel-programming.git
```

#### 4. Navigate to the project directory:

```
cd parallel-programming
```

#### 5. Unzip the 500f.zip file:

```sh
unzip 500f.zip
```

#### 6. Use "cd" and "ls" commands to navigate to the necessary variant:

In case to navigate to the 9th variant use command below:

```sh
cd ~/parallel-programming/2/fork/linux
```

#### 7. Inspect README.md file before do something

```sh
less README.md
```

#### 8. (Recommended) Make a backup of a code:

```sh
cp main.cpp main.bk.cpp
```

where "main.cpp" may be different filename (i.e. fork2.cpp)

use "ls" command to check a content of the current directory

#### 9. Edit the code:

To get a count of an available (logical) threads use command below:

```sh
nproc
```

To get username enter command below:

```sh
whoami
```

or

```sh
echo $USER
```

Edit the code using one of "nano", "vi", "vim" text editor:

i.e. using nano:

```sh
nano main.cpp
```

or another .cpp filename. Use "ls" command to verify it

Inspect the comments
###### !Don't forget to change file paths to the proper values!

Save changes and exit

#### 10. Compile a program:

```sh
g++ main.cpp
```

file "a.out" will appear in the current directory

"a.out" is a default binary name in gcc or g++ compilers

Use -o (or --output) option to change an executable (binary) filename:

```sh
g++ -o binary_name.exe main.cpp
```

If a program uses thread method use command bellow:

```sh
g++ -lpthread main.cpp
```

If a program uses openMP method use command bellow:

```sh
g++ -fopenmp main.cpp
```

#### 11. Execute the binary:

```sh
./a.out
```

or another binary name that was entered after -o option

#### 12. If result wasn't in stdout you need to read "result" file(s):

```sh
cat ~/parallel-programming/500f/result*
```