Linux and UNIX Man Pages

Test Your Knowledge in Computers #353
Difficulty: Medium
mawk is a very fast AWK implementation by Mike Brennan based on a Python interpreter.
True or False?
Linux & Unix Commands - Search Man Pages

vop_ioctl(9) [posix man page]

VOP_IOCTL(9)						   BSD Kernel Developer's Manual					      VOP_IOCTL(9)

VOP_IOCTL -- device specific control SYNOPSIS
#include <sys/param.h> #include <sys/vnode.h> int VOP_IOCTL(struct vnode *vp, u_long command, caddr_t data, int fflag, struct ucred *cred, struct thread *td); DESCRIPTION
Manipulate a file in device dependent ways. Its arguments are: vp The vnode of the file (normally representing a device). command The device specific operation to perform. data Extra data for the specified operation. fflag Some flags ??? cred The caller's credentials. td The calling thread. Most file systems do not implement this entry point. LOCKS
The file should not be locked on entry. RETURN VALUES
If successful, zero is returned, otherwise an appropriate error code. If the ioctl is not recognized or not handled, ENOTTY should be returned. SEE ALSO
vnode(9) AUTHORS
This manual page was written by Doug Rabson. BSD
July 24, 1996 BSD

Check Out this Related Man Page

VOP_OPEN(9)						   BSD Kernel Developer's Manual					       VOP_OPEN(9)

VOP_OPEN, VOP_CLOSE -- open or close a file SYNOPSIS
#include <sys/param.h> #include <sys/vnode.h> int VOP_OPEN(struct vnode *vp, int mode, struct ucred *cred, struct thread *td, struct file *fp); int VOP_CLOSE(struct vnode *vp, int mode, struct ucred *cred, struct thread *td); DESCRIPTION
The VOP_OPEN() entry point is called before a file is accessed by a process and the VOP_CLOSE() entry point is called after a file is fin- ished with by the process. The arguments are: vp The vnode of the file. mode The access mode required by the calling process. cred The caller's credentials. td The thread which is accessing the file. fp The file being opened. Pointer to the file fp is useful for file systems which require such information, e.g., fdescfs(5). Use 'NULL' as fp argument to VOP_OPEN() for in-kernel opens. The access mode is a set of flags, including FREAD, FWRITE, O_NONBLOCK, O_APPEND. LOCKS
VOP_OPEN() expects vp to be locked on entry and will leave it locked on return. VOP_CLOSE() expects at least a reference to be associated with the vnode and does not care whether the vnode is locked or not. The lock and reference state is left unchanged on return. Note that vn_close expects an unlocked, referenced vnode and will dereference the vnode prior to returning. RETURN VALUES
Zero is returned on success, otherwise an error code is returned. SEE ALSO
This manual page was written by Doug Rabson. BSD
December 2, 2009 BSD

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Why does /bin contain binaries for builtins?

Why do shell builtins like echo and pwd have binaries in /bin? When I do which pwd, I get the one in /bin. that means that I am not using the builtin version? What determines which one gets used? Is the which command a definitive way to determine what is being run when I enter pwd? (16 Replies)
Discussion started by: glev2005
16 Replies

2. Tips and Tutorials

Unix File Permissions

Introduction I have seen some misinformation regarding Unix file permissions. I will try to set the record straight. Take a look at this example of some output from ls: $ ls -ld /usr/bin /usr/bin/cat drwxrwxr-x 3 root bin 8704 Sep 23 2004 /usr/bin -r-xr-xr-x 1 bin bin ... (6 Replies)
Discussion started by: Perderabo
6 Replies

3. Shell Programming and Scripting

Scripts without shebang

I see lot of ad-hoc shell scripts in our servers which don't have a shebang at the beginning . Does this mean that it will run on any shell ? Is it a good practice to create scripts (even ad-hoc ones) without shebang ? (16 Replies)
Discussion started by: kraljic
16 Replies

4. UNIX for Advanced & Expert Users

When is a _function_ not a _function_?

For a starter I know the braces are NOT in the code... Consider these code snippets:- #!/bin/bash --posix x=0 somefunction() if then echo "I am here." fi # somefunction #!/bin/bash --posix x=0 somefunction() if (2 Replies)
Discussion started by: wisecracker
2 Replies

5. Fedora

Is UNIX an open source OS ?

Hi everyone, I know the following questions are noobish questions but I am asking them because I am confused about the basics of history behind UNIX and LINUX. Ok onto business, my questions are-: Was/Is UNIX ever an open source operating system ? If UNIX was... (21 Replies)
Discussion started by: sreyan32
21 Replies

6. OS X (Apple)

Installing Dash Shell on OS X Lion

For those interested in installing dash shell on OSX Lion to help test POSIX compliancy of shell scripts, it is quite easy. I did it like this: If you don't have gcc on your system: 0. Download and install the Command Line Tools for Xcode package from Sign In - Apple * 1. Download the dash... (2 Replies)
Discussion started by: Scrutinizer
2 Replies

7. Shell Programming and Scripting

Equivalent to let command in POSIX shell

Hi all, I am learning POSIX shell programming, and the book I read, uses the let command for integer arithmetic. I have downloaded and use the shellcheck program on Linux. This programs says: In POSIX sh, 'let' is undefined. See the screenshot attached. What is the POSIX... (1 Reply)
Discussion started by: johnprogrammer
1 Replies

8. What is on Your Mind?

I'll probably never be the best in the field...

I don't know how to start this but here goes. I've been "using" Linux for over 10 years, possibly more and I still feel like I'm nowhere where I should be. I'll be fair most of my time was spent either figuring out how to run games on *nix at the time but as I got older and "wiser" I... (8 Replies)
Discussion started by: samthewildone
8 Replies

9. UNIX for Advanced & Expert Users

[Tip] How to display the number of logged-in users

In a professional environment with traditional application you often want (or are asked) to report the users. Traditionally there is the who command who | awk '{print $1}'telnetd or sshd register the users in the utmp file, to be shown with who, w, users, finger, pinky, ... In addition they... (1 Reply)
Discussion started by: MadeInGermany
1 Replies

10. What is on Your Mind?

The square root code I coded on this site...

Hi all, (mainly Neo)... I keep noticing that the SQRT code I wrote recently for a POSIX shell keeps appearing, (the green colour sticks out like a sore thumb). So I decided to take a look on Google. Guess what? UNIX.COM comes first in Google's listing just from two words, see image... (2 Replies)
Discussion started by: wisecracker
2 Replies

Featured Tech Videos