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41 .Dd September 18, 2010
46 .Nd file-descriptor file system
49 fdescfs /dev/fd fdescfs rw 0 0
52 The file-descriptor file system, or
54 provides access to the per-process file descriptor
55 namespace in the global file system namespace.
56 The conventional mount point is
59 The file system's contents
60 appear as a list of numbered files
61 which correspond to the open files of the process reading the
67 refer to file descriptors which can be accessed through the file
69 If the file descriptor is open and the mode the file is being opened
70 with is a subset of the mode of the existing descriptor, the call:
71 .Bd -literal -offset indent
72 fd = open("/dev/fd/0", mode);
76 .Bd -literal -offset indent
77 fd = fcntl(0, F_DUPFD, 0);
96 files are created by default when devfs alone is mounted.
98 creates entries for all file descriptors opened by the process.
100 .Bl -tag -width /dev/stderr -compact
109 .Dl "mount -t fdescfs null /dev/fd"
116 file system first appeared in
120 manual page first appeared in
126 manual page was written by
127 .An Mike Pritchard Aq mpp@FreeBSD.org ,
129 manual page written by
130 .An Jan-Simon Pendry .