A Practical Guide to Red Hat® Linux® 8

System Calls

Three fundamental responsibilities of the Linux kernel are to control processes, manage the filesystem, and operate peripheral devices. As a programmer you have access to these kernel operations through system calls and library functions. This section discusses system calls at a general level; a detailed treatment is beyond the scope of this book.

As the name implies, a system call instructs the system (kernel) to perform some work directly on your behalf. The request is a message that tells the kernel what work needs to be done and includes the necessary arguments. For example, a system call to open a file includes the name of the file. A library routine is indirect; it issues system calls for you. The advantages of a library routine ...