1<html lang="en"> 2<head> 3<title>Syscalls - Untitled</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Untitled"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="prev" href="Misc.html#Misc" title="Misc"> 9<link rel="next" href="Arglists.html#Arglists" title="Arglists"> 10<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 11<meta http-equiv="Content-Style-Type" content="text/css"> 12<style type="text/css"><!-- 13 pre.display { font-family:inherit } 14 pre.format { font-family:inherit } 15 pre.smalldisplay { font-family:inherit; font-size:smaller } 16 pre.smallformat { font-family:inherit; font-size:smaller } 17 pre.smallexample { font-size:smaller } 18 pre.smalllisp { font-size:smaller } 19 span.sc { font-variant:small-caps } 20 span.roman { font-family:serif; font-weight:normal; } 21 span.sansserif { font-family:sans-serif; font-weight:normal; } 22--></style> 23<link rel="stylesheet" type="text/css" href="../cs.css"> 24</head> 25<body> 26<div class="node"> 27<a name="Syscalls"></a> 28<p> 29Next: <a rel="next" accesskey="n" href="Arglists.html#Arglists">Arglists</a>, 30Previous: <a rel="previous" accesskey="p" href="Misc.html#Misc">Misc</a>, 31Up: <a rel="up" accesskey="u" href="index.html#Top">Top</a> 32<hr> 33</div> 34 35<h2 class="chapter">12 System Calls</h2> 36 37<p><a name="index-linking-the-C-library-461"></a>The C subroutine library depends on a handful of subroutine calls for 38operating system services. If you use the C library on a system that 39complies with the POSIX.1 standard (also known as IEEE 1003.1), most of 40these subroutines are supplied with your operating system. 41 42 <p>If some of these subroutines are not provided with your system—in 43the extreme case, if you are developing software for a “bare board” 44system, without an OS—you will at least need to provide do-nothing 45stubs (or subroutines with minimal functionality) to allow your 46programs to link with the subroutines in <code>libc.a</code>. 47 48<ul class="menu"> 49<li><a accesskey="1" href="Stubs.html#Stubs">Stubs</a>: Definitions for OS interface 50<li><a accesskey="2" href="Reentrant-Syscalls.html#Reentrant-Syscalls">Reentrant Syscalls</a>: Reentrant covers for OS subroutines 51</ul> 52 53 </body></html> 54 55