syscalls_24.html

Linux系统调用

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<TITLE>Syscall specifications of Linux - read</TITLE>
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<H2><A NAME="SEC24" HREF="syscalls_toc.html#SEC24" tppabs="http://personal.xfol.com/%7erezaie/syscall/syscalls_toc.html#SEC24">read</A></H2>
<P>
<H3>SYNOPSIS</H3>
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<CODE>int read(int <VAR>fd</VAR>, char *<VAR>buf</VAR>, size_t <VAR>count</VAR>);</CODE>
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<H3>PARAMETERS</H3>
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<VAR>fd</VAR>: [in] the file descriptor to read from.
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<VAR>buf</VAR>: [out] the buffer that will contain information read.
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<VAR>count</VAR>: [in] the maximal size of <VAR>buf</VAR>. 
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<H3>DESCRIPTION</H3>
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Reads up to <VAR>count</VAR> bytes into <VAR>buf</VAR> from <VAR>fd</VAR>. 
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<H3>RETURN VALUE</H3>
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On success zero is returned. On error, -1 is returned and <CODE>errno</CODE> is
set to one of the following values:
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<UL>
<LI><CODE>EINVAL</CODE>: <VAR>fd</VAR> cannot be read.
<LI><CODE>EINTR</CODE>, <CODE>EAGAIN</CODE>, <CODE>EISDIR</CODE>, <CODE>EBADF</CODE> and
<CODE>EFAULT</CODE>.
</UL>
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