FreeBSD Manual Pages
FDESCFS(5) File Formats Manual FDESCFS(5) NAME fdescfs -- file-descriptor file system SYNOPSIS fdescfs /dev/fd fdescfs rw 0 0 DESCRIPTION The file-descriptor file system, or fdescfs, provides access to the per-process file descriptor namespace in the global file system name- space. The conventional mount point is /dev/fd. The file system's contents appear as a list of numbered files which correspond to the open files of the process reading the directory. The files /dev/fd/0 through /dev/fd/# refer to file descriptors which can be accessed through the file system. If the file descriptor is open and the mode the file is being opened with is a subset of the mode of the existing descriptor, the call: fd = open("/dev/fd/0", mode); and the call: fd = fcntl(0, F_DUPFD, 0); are equivalent. Flags to the open(2) call other than O_RDONLY, O_WRONLY and O_RDWR are ignored. Note: /dev/fd/0, /dev/fd/1 and /dev/fd/2 files are created by default when devfs alone is mounted. fdescfs creates entries for all file de- scriptors opened by the process. FILES /dev/fd/# EXAMPLES To mount a fdescfs volume located on /dev/fd: mount -t fdescfs null /dev/fd SEE ALSO devfs(5), mount(8) HISTORY The fdescfs file system first appeared in 4.4BSD. The fdescfs manual page first appeared in FreeBSD 2.2. AUTHORS The fdescfs manual page was written by Mike Pritchard <mpp@FreeBSD.org>, and was based on the manual page written by Jan-Simon Pendry. FreeBSD 10.3 September 18, 2010 FDESCFS(5)
NAME | SYNOPSIS | DESCRIPTION | FILES | EXAMPLES | SEE ALSO | HISTORY | AUTHORS
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=fdescfs&sektion=5&manpath=FreeBSD+10.3-RELEASE>