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	 0d35a59ce3
			
		
	
	
		0d35a59ce3
		
			
		
	
	
	
	
		
			
			- check for ``dup()`` libc function - handle missing ``F_DUPFD`` in ``dup2()`` replacement function - add workaround for WASI libc bug in MSG_TRUNC - ESHUTDOWN is missing, use EPIPE instead - POLLPRI is missing, define as 0 (no-op)
		
			
				
	
	
		
			37 lines
		
	
	
	
		
			855 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			37 lines
		
	
	
	
		
			855 B
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Public domain dup2() lookalike
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|  * by Curtis Jackson @ AT&T Technologies, Burlington, NC
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|  * electronic address:  burl!rcj
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|  *
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|  * dup2 performs the following functions:
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|  *
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|  * Check to make sure that fd1 is a valid open file descriptor.
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|  * Check to see if fd2 is already open; if so, close it.
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|  * Duplicate fd1 onto fd2; checking to make sure fd2 is a valid fd.
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|  * Return fd2 if all went well; return BADEXIT otherwise.
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|  */
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| 
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| #include <errno.h>
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| #include <fcntl.h>
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| #include <unistd.h>
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| 
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| #define BADEXIT -1
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| 
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| int
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| dup2(int fd1, int fd2)
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| {
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|     if (fd1 != fd2) {
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| #ifdef F_DUPFD
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|         if (fcntl(fd1, F_GETFL) < 0)
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|             return BADEXIT;
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|         if (fcntl(fd2, F_GETFL) >= 0)
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|             close(fd2);
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|         if (fcntl(fd1, F_DUPFD, fd2) < 0)
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|             return BADEXIT;
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| #else
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|         errno = ENOTSUP;
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|         return BADEXIT;
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| #endif
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|     }
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|     return fd2;
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| }
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