OCP, OverlycomplicatedCP

This project reimplements the basic functionality of copying a file from one location into another, this is achieved by launching the command in two separates processes which will communicate over one of two IPC methods to achieve the transfer of the required data

The two processes will act as either a "sender", tasked with reading data from the source file and sending it to the other process, which will act as a "receiver" to write the data onto the designated destination file

The two methods of IPC will be:

• Pipes (FIFO)
• Shared memory

Structure of the project

The project will result in a single binary which will contain the necessary information for both roles and for both IPC methods

The src folder will be divided into a folder for the FIFO methods (src/pipe), a folder for the shared memory methods (src/shm) and a folder for shared utilities (src/shared)

Usage

Either process (sender or receiver) can be launched first, the processes will coordinate to only start the copy process when they all are ready.

Pairing of sender and receiver is achieved through the pass parameter, which should be a unique identifier for the operation desired, this allows running multiple copy operations between different pairs of senders and receivers at the same time.
The password must not begin with a /

The file option is interpreted as the input file when passed to the sender or as the output destination when passed to the receiver

The role option can be either s for sender or r for receiver

The method option can be either p for PIPE (FIFO) based ICP or s for shared memory

Options:

--pass <pass>, -p <pass>, The unique ID for the copy/paste pair of executions
--file <name>, -f <name>, The program is going to write the received data into the file at <name>
--method <method>, -m <method>, The program is going to use the specified method to execute the copy/paste pair of executions
--role <role>, -r <role>, <role> can be either sender or receiver and specifies how the program is going to act

Example to copy file "test.txt" to destination "copy" using pipes:

ocp -r send -p example123 -m p -f test.txt
ocp -r receive -p example123 -m p -f copy

Building

We used the meson build system, installation instructions for which can be found at the official meson website

Once meson is installed running the setup.sh script will create the build directory and executing the meson compile ocp in this new directory (builddir) will compile and link the program creating the ocp binary

To build in release mode run the following commands:

./setup.sh
./config-meson.sh -r
meson compile -C builddir

Dependencies

On top of meson and gcc the following dependencies are required:

• xxd
• openssl
• libssl-dev

On ubuntu these can be installed with: sudo apt install xxd openssl libssl-dev

Warning

The program must be built with meson as it generates the header file for the help message, if not using meson then an equivalent header file containing the ___src_help_str_txt_len and ___src_help_str_txt variables must be generated