38 lines
1.7 KiB
HTML
38 lines
1.7 KiB
HTML
<html><!-- This HTML file has been created by texi2html 1.29
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from syscalls.texi on 4 June 1994 -->
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<TITLE>Syscall specifications of Linux - dup</TITLE>
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<P>Go to the <A HREF="syscalls_10.html" tppabs="http://www.infran.ru/TechInfo/syscalls/syscalls_10.html">previous</A>, <A HREF="syscalls_12.html" tppabs="http://www.infran.ru/TechInfo/syscalls/syscalls_12.html">next</A> section.<P>
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<H2><A NAME="SEC11" HREF="syscalls_toc.html#SEC11" tppabs="http://www.infran.ru/TechInfo/syscalls/syscalls_toc.html#SEC11">dup and dup2</A></H2>
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<P>
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<H3>SYNOPSIS</H3>
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<P>
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<CODE>int dup(int <VAR>oldfd</VAR>);</CODE>
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<P>
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<CODE>int dup2(int <VAR>oldfd</VAR>, int <VAR>newfd</VAR>);</CODE>
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<P>
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<H3>PARAMETERS</H3>
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<P>
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<VAR>oldfd</VAR>: [in] the file descriptor to copy.
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<P>
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<VAR>newfd</VAR>: [in] the file descriptor to copy to.
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<P>
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<H3>DESCRIPTION</H3>
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<P>
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<CODE>dup</CODE> duplicates a file descriptor to the lowest unused file
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descriptor available. <CODE>dup2</CODE> duplicates a file descriptor to
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another specified file descriptor. If the destination file descriptor is
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already used, it is closed. The two descriptors share all (ie. file
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locks, position, etc.) but the close-on-exec flag.
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<P>
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<H3>RETURN VALUE</H3>
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<P>
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The call returns the new descriptor on success. It returns -1 on error
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and sets <CODE>errno</CODE> to one of the following values: <CODE>EBADF</CODE> or
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<CODE>EMFILE</CODE>.
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<P>
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<STRONG>NOTE</STRONG>: <CODE>EINVAL</CODE> might well be added to the set of possible
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errors in the future. (Take a look in the kernel source.)
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<P>
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<P>Go to the <A HREF="syscalls_10.html" tppabs="http://www.infran.ru/TechInfo/syscalls/syscalls_10.html">previous</A>, <A HREF="syscalls_12.html" tppabs="http://www.infran.ru/TechInfo/syscalls/syscalls_12.html">next</A> section.<P>
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