30 lines
538 B
C
30 lines
538 B
C
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#include <lib.h>
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#define dup2 _dup2
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#include <fcntl.h>
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#include <limits.h>
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#include <errno.h>
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PUBLIC int dup2(fd, fd2)
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int fd, fd2;
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{
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/* The behavior of dup2 is defined by POSIX in 6.2.1.2 as almost, but not
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* quite the same as fcntl.
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*/
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if (fd2 < 0 || fd2 > OPEN_MAX) {
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errno = EBADF;
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return(-1);
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}
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/* Check to see if fildes is valid. */
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if (fcntl(fd, F_GETFL) < 0) {
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/* fd is not valid. */
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return(-1);
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} else {
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/* fd is valid. */
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if (fd == fd2) return(fd2);
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close(fd2);
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return(fcntl(fd, F_DUPFD, fd2));
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}
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}
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