From 7e0f021a9aec35fd8e6725e87e3313b101d26f5e Mon Sep 17 00:00:00 2001 From: Tobias Klauser Date: Sun, 27 Jan 2008 11:37:44 +0100 Subject: Initial import (2.0.2-6) --- reference/C/LIBRARIES/syscalls.htm | 61 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 reference/C/LIBRARIES/syscalls.htm (limited to 'reference/C/LIBRARIES/syscalls.htm') diff --git a/reference/C/LIBRARIES/syscalls.htm b/reference/C/LIBRARIES/syscalls.htm new file mode 100644 index 0000000..e74dd70 --- /dev/null +++ b/reference/C/LIBRARIES/syscalls.htm @@ -0,0 +1,61 @@ + + +System calls and library calls + + + + +

+ +

System calls and library calls

+ +

+ +I have wondered for sometime what the difference is between +system calls (found in section 2 of the man pages) +and library calls (in section 3). + +Its simple... + +

system calls are provided by the system +and are executed in the system kernel. They are entry points +into the kernel and are therefore NOT linked into your +program. These are not portable +calls. +
Library calls include the ANSI C standard library and are +therefore portable. These functions are linked into your program. +

+ +It is worth noting that, because system calls are part of the +O/S. The program has to make a context switch to the kernel +when they are called and because of this, they have a high +startup overhead. The upside is that the time executing these +routines is assigned to the OS and not the user program. + +

+ + + + +

+ Top +

+ Master Index +

+ Keywords +

+ Functions +

+ +

Martin Leslie +

+ + -- cgit v1.2.3-54-g00ecf