Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

fdescfs(5) [freebsd man page]

FDESCFS(5)						      BSD File Formats Manual							FDESCFS(5)

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 names- pace. 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 descriptors 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 <>, and was based on the manual page written by Jan-Simon Pendry. BSD
September 18, 2010 BSD

Check Out this Related Man Page

DEVFS(5)						      BSD File Formats Manual							  DEVFS(5)

devfs -- device file system SYNOPSIS
devfs /dev devfs rw 0 0 DESCRIPTION
The device file system, or devfs, provides access to kernel's device namespace in the global file system namespace. The conventional mount point is /dev. The file system includes several directories, links, symbolic links and devices, some of which can also be written. In a chroot'ed environ- ment, devfs can be used to create a new /dev mount point. The mknod(8) tool can be used to recover deleted device entries under devfs. The fdescfs(5) filesystem is an alternate means for populating /dev/fd. The character devices that both devfs and fdescfs(5) present in /dev/fd correspond to the open file descriptors of the process accessing the directory. devfs only creates files for the standard file descriptors 0, 1 and 2. fdescfs(5) creates files for all open descriptors. The options are as follows: -o options Use the specified mount options, as described in mount(8). The following devfs file system-specific options are available: ruleset=ruleset Set ruleset number ruleset as the current ruleset for the mount-point and apply all its rules. If the ruleset number ruleset does not exist, an empty ruleset with the number ruleset is created. See devfs(8) for more information on working with devfs rulesets. FILES
/dev The normal devfs mount point. EXAMPLES
To mount a devfs volume located on /mychroot/dev: mount -t devfs devfs /mychroot/dev SEE ALSO
fdescfs(5), devfs(8), mount(8) HISTORY
The devfs file system first appeared in FreeBSD 2.0. It became the preferred method for accessing devices in FreeBSD 5.0 and the only method in FreeBSD 6.0. The devfs manual page first appeared in FreeBSD 2.2. AUTHORS
The devfs manual page was written by Mike Pritchard <>. BSD
February 9, 2012 BSD
Man Page

11 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

/dev/null 2>&1 question

Hi, suppose you have the following line at your crontab : 5 * * * * /usr/mine/script > /dev/null 2>&1 now i understood that the " > /dev/null 2>&1 outputs both Standard outpout and Standard Error messages to the /dev/null device or file... the first part , " > /dev/null " transfers... (1 Reply)
Discussion started by: BAM
1 Replies

2. UNIX for Dummies Questions & Answers


Hi , I am importing some table from /dev/null i dont understand what is /dev/null Sorry i am new to UNIX sam71 (3 Replies)
Discussion started by: sam71
3 Replies

3. HP-UX

How to get the opened files by a process

Hi, i'd like to get the files which are opened by a process during his execution using the c language. Thanks for helping me. (2 Replies)
Discussion started by: benoit.gaillard
2 Replies

4. Solaris

Funky behavior that im noticing

I was just messing around on my test system, Is sending a file to the /dev/null i.e. mv testfile /dev/null is this the same as erasing the file, because I've been noticing some weird behavior since I did this. like the following when i execute commands... sh: /dev/null: cannot create sh:... (4 Replies)
Discussion started by: BG_JrAdmin
4 Replies

5. AIX

Can't mount showing 0506-342 The superblock on /dev/fslv00 is dirty

Dear All Last day in Aix 5.2 server by executing # df –g I found following: Filesystem GB blocks Free %Used Iused %Iused Mounted on . . /dev/fslv00 58.00 136.70 -135% 212103 1% /sprod After shutting down by following command # shutdown –h And when... (1 Reply)
Discussion started by: xa52000
1 Replies

6. UNIX for Dummies Questions & Answers

how to access files via their descriptors?

hello, I'm new here, and new to Linux. I was wondering how to get hold of a certain file's descriptor, and how to use that number so that I access the contents of the file. please give me a full example, that is (1) how to determine the descriptor and (2) what magic symbols to use so that... (4 Replies)
Discussion started by: ialoq
4 Replies

7. UNIX for Dummies Questions & Answers

help with sorting files

find / -type f 2> /dev/null | find -inum +1 2> /dev/null | find -mtime -30 2> /dev/null what i am trying to do i search all regular files in root directory with one or more inodes modified within last 30 days. the /dev/null is to suppress the permission denied outputs. i am now trying to... (5 Replies)
Discussion started by: iluvsushi
5 Replies

8. Shell Programming and Scripting

Meaning of 2>/dev/null/ <<EOF ?

I am new to unix and learning. Came across this statement cmd 2>/dev/null/ <<EOF 2>/dev/null/ denotes that std error is stored in /dev/null but that is considered as a non-existent file!! What does << EOF mean and how does it affect? I am really confused.. :wall: Can some one explain this... (2 Replies)
Discussion started by: source
2 Replies

9. UNIX for Advanced & Expert Users

Close file descriptor without terminating process

Can any help me in finding the way to close opened file descriptor in Solaris ,without killing process. As accidently a file was removed which was opened by a process. Much thanks in advance :) (11 Replies)
Discussion started by: nitj
11 Replies

10. Red Hat

Process to use open files

I would like to test open files usage in my system, if I want to create a process ( or script ) that can use a certain amount ( eg. 1000 ) of open files , is it possible to create such process ( or script ) ? (3 Replies)
Discussion started by: ust
3 Replies

11. AIX

Housekeeping null 2>&1 in /dev

Hello, Does anyone know how to housekeeping the null 2>&1 file in /dev? its fill up my system, please help. Thanks :b: (3 Replies)
Discussion started by: only
3 Replies

Featured Tech Videos