Example of Standard C Library

• The standard C library provides a portion of the system call interface for many version of UNIX and Linux.
• As an example, let's assume a C program invokes printf() statement.
• The C library intercepts this call and invokes the necessary system call(s) in the OS.
• The C library takes the value returned by write() and passes it back to the user program (see Fig. 7).

Figure 7: C library handling of write().