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diff --git a/reference/C/MAN/dup2.htm b/reference/C/MAN/dup2.htm new file mode 100644 index 0000000..74e702f --- /dev/null +++ b/reference/C/MAN/dup2.htm @@ -0,0 +1,98 @@ +<TITLE>dup2</TITLE> +<body bgcolor="#ffffcc"> +<hr> +<pre> + + + +<h3>DUP(2) Linux Programmer's Manual DUP(2) +</h3> + +<h3>NAME +</h3> dup, dup2 - duplicate a file descriptor + +<h3>SYNOPSIS +</h3> #include <unistd.h> + + int dup(int oldfd); + int dup2(int oldfd, int newfd); + +<h3>DESCRIPTION +</h3> dup and dup2 create a copy of the file descriptor oldfd. + + The old and new descriptors may be used interchangeably. + They share locks, file position pointers and flags; for + example, if the file position is modified by using lseek + on one of the descriptors, the position is also changed + for the other. + + The two descriptors do not share the close-on-exec flag, + however. + + dup uses the lowest-numbered unused descriptor for the new + descriptor. + + dup2 makes newfd be the copy of oldfd, closing newfd first + if necessary. + +<h3>RETURN VALUE +</h3> dup and dup2 return the new descriptor, or -1 if an error + occurred (in which case, errno is set appropriately). + +<h3>ERRORS +</h3> EBADF oldfd isn't an open file descriptor, or newfd is + out of the allowed range for file descriptors. + + EMFILE The process already has the maximum number of file + descriptors open and tried to open a new one. + +<h3>WARNING +</h3> The error returned by dup2 is different to that returned + by fcntl(...,F_DUPFD,...) when newfd is out of range. On + some systems dup2 also sometimes returns EINVAL like + F_DUPFD. + +<h3>CONFORMING TO +</h3> SVID, AT&T, POSIX, X/OPEN, BSD 4.3 + +</pre> +<hr> +<h3>SEE ALSO +</h3><p> +<a href=fcntl.htm>fcntl</a>, +<a href=open.htm>open</a>, +<pre> + + + + + + + + +<h3>Linux 1.1.46 21 August 1994 1 +</h3> + +
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