How Does Named Pipe Work in Linux?

Named pipes, also known as FIFO (First In, First Out), are a type of inter-process communication (IPC) mechanism in Linux that allows processes to communicate with each other through a file-like interface.

How Named Pipes Work

1. Creating a Named Pipe:

   • Use the mkfifo command to create a named pipe.
   • The command takes the name of the pipe as an argument.
   • For example, mkfifo mypipe creates a named pipe called "mypipe".

2. Opening the Pipe:

   • Processes can open the named pipe using standard file open functions like open().
   • The opened pipe can be used for reading or writing, similar to a regular file.

3. Communication:

   • When a process writes to the named pipe, the data is stored in a buffer until another process reads it.
   • When a process reads from the named pipe, it retrieves the data from the buffer.
   • The data is transferred in a FIFO manner, meaning the first data written to the pipe is the first data read.

4. Closing the Pipe:

   • When a process finishes using the named pipe, it should close the pipe using the close() function.

Example

# Create a named pipe
mkfifo mypipe

# Process 1: Writes to the pipe
echo "Hello from process 1" > mypipe

# Process 2: Reads from the pipe
cat mypipe

This example creates a named pipe called "mypipe". Process 1 writes the message "Hello from process 1" to the pipe, and process 2 reads the message from the pipe.

Advantages of Named Pipes

• Simple to Use: Named pipes provide a straightforward file-like interface for communication.
• Flexible: They can be used for communication between processes running on the same or different machines.
• Reliable: They are a reliable communication mechanism, ensuring data is delivered in order.

Disadvantages of Named Pipes

• Limited Buffer Size: The buffer size of a named pipe is limited, potentially causing data loss if one process writes faster than another reads.
• Blocking: If a process tries to read from an empty pipe or write to a full pipe, it will block until data is available or space is freed.

Conclusion

Named pipes provide a simple and reliable way for processes to communicate in Linux. They offer a file-like interface, making them easy to use and integrate into existing applications. While they have some limitations, they are a valuable tool for inter-process communication.