Comparison between linux and C-database functions

Comparison between linux system calls and C-library functions-Linux general technology-Linux programming and kernel information. The following is a detailed description. 1. system calls can directly access the rich services of the Linux kernel, such as file descriptor-based I/O operations (library C functions are based on file pointers ). Therefore, the system call can be considered as a low-level kernel interface, while the C library call is at a high level of the Linux programming interface. In fact, many library functions are implemented by system calls. For example, malloc is implemented by the system call sbrk.

2. system calls exist in kernel space, and most library calls are user-mode routines. Therefore, system calls may damage the system, and there are many risks of library calls.

3. Library portability is also a major advantage

Note: This document is excerpted from the GNU/Linux programming guide by Kurt Wall (US) and published by Tsinghua University Press P183.