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37 .Dd September 18, 2010
42 .Nd file-descriptor file system
45 fdescfs /dev/fd fdescfs rw 0 0
48 The file-descriptor file system, or
50 provides access to the per-process file descriptor
51 namespace in the global file system namespace.
52 The conventional mount point is
55 The file system's contents
56 appear as a list of numbered files
57 which correspond to the open files of the process reading the
63 refer to file descriptors which can be accessed through the file
65 If the file descriptor is open and the mode the file is being opened
66 with is a subset of the mode of the existing descriptor, the call:
67 .Bd -literal -offset indent
68 fd = open("/dev/fd/0", mode);
72 .Bd -literal -offset indent
73 fd = fcntl(0, F_DUPFD, 0);
92 files are created by default when devfs alone is mounted.
94 creates entries for all file descriptors opened by the process.
96 .Bl -tag -width /dev/stderr -compact
105 .Dl "mount -t fdescfs null /dev/fd"
112 file system first appeared in
116 manual page first appeared in
122 manual page was written by
123 .An Mike Pritchard Aq mpp@FreeBSD.org ,
125 manual page written by
126 .An Jan-Simon Pendry .