Read and write functions in the Unix/linux

File descriptor

For the kernel, all open files are referenced by a file descriptor. The file descriptor is a non-negative integer. When an existing file is opened or a new file is created, the kernel returns a file descriptor to the process. When reading or writing a file, use the file descriptor returned by open or create to represent the file and pass it as a parameter to the read or write function.

Read function

#include <unistd>ssize_t read (intvoid *buf, size_t nbytes); // Returns : Returns the number of bytes read if successful, or 0 if the end of the file returns 1 if an error occurs. // filedes: File descriptor // buf: Reading data buffers // nbytes: Number of bytes to read

Write function

Resources

Read and write functions in the Unix/linux