xnu-6153.11.26.tar.gz

[apple/xnu.git] / bsd / man / man2 / exchangedata.2

diff --git a/bsd/man/man2/exchangedata.2 b/bsd/man/man2/exchangedata.2
index cc2111ea48625cee6a63e7d649cde0e34fc86c96..48d05b6c8f8f0268231e3c85c5b754b0547a89f2 100644 (file)
--- a/bsd/man/man2/exchangedata.2
+++ b/bsd/man/man2/exchangedata.2
@@ -24,8 +24,9 @@
 .Nd atomically exchange data between two files
 .Sh SYNOPSIS
 .Fd #include <unistd.h>
+.Fd #include <sys/attr.h>
 .Ft int
-.Fn exchangedata "const char * path1" "const char * path2" "unsigned long options"
+.Fn exchangedata "const char * path1" "const char * path2" "unsigned int options"
 .
 .Sh DESCRIPTION
 The
@@ -72,6 +73,16 @@ Programs that reference the file via an object identifier will continue to
 reference the original file, but now it has the new data.
 .Pp
 .
+WARNING: This system call is largely supported only by HFS and AFP file systems.  Many other
+file systems, including APFS, do not support it.  Further, it is not supported on iOS, tvOS, or watchOS. 
+It is recommended that callers refer
+instead to 
+.Fn rename
+or
+.Fn renamex_np
+to conduct safe-save operations instead. 
+.Pp
+.
 .\" path1 and path2 parameters
 .
 The
@@ -114,6 +125,7 @@ is set to indicate the error.
 .Sh COMPATIBILITY
 Not all volumes support 
 .Fn exchangedata .
+This includes APFS volumes.
 You can test whether a volume supports 
 .Fn exchangedata 
 by using 
@@ -181,10 +193,12 @@ An I/O error occurred while reading from or writing to the file system.
 .
 .Sh SEE ALSO
 .
-.Xr getattrlist 2
+.Xr getattrlist 2 ,
+.Xr rename 2
 .
 .Sh HISTORY
 A
 .Fn exchangedata
 function call appeared in Darwin 1.3.1 (Mac OS X version 10.0).
 .
+It was deprecated in macOS 10.13.