Sponsored Content
Top Forums UNIX for Dummies Questions & Answers how to read or write device files Post 94751 by Perderabo on Tuesday 3rd of January 2006 04:27:53 PM
Old 01-03-2006
/dev/tty is a device file. Try this:
echo hello > /dev/tty
See? You just wrote on a device file. You write to them like any other file.

HOWEVER!!!! You cannot use mknod and create usable device file unless you know exactly what you are doing. mknod is the last step. First you write a device driver, then you install the driver into your kernel, and finally you use mknod to create a device file that points to your new driver.
 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

How to read and write files one line at a time.

Hi! All! I am wirting a shell script in which i want to read one line at a time from the file and write it simultaneouly to other file one line at a time. Please let me know about some shell utility which can help me out. Thanx. If further clarifications are needed then please let me know... (2 Replies)
Discussion started by: s_chopra
2 Replies

2. Shell Programming and Scripting

Script with read/write Files

Hello, I am a Newbie in ksh Unix Script. So I must write a ksh/sh script who read character at a position in a File. So also it must read all the lines who belongs at these characters , then write these lines in a another File. Can you help me , or give little councils to advance with my... (5 Replies)
Discussion started by: steiner
5 Replies

3. UNIX for Dummies Questions & Answers

how to read and write device registers

hello friends, While in the process of writing device drivers, i am facing problem in reading and writing device registers.I got base address of those mapped device registers. Can i add offset of those registers to that Base address to get access of those... (1 Reply)
Discussion started by: sriram.ec
1 Replies

4. Shell Programming and Scripting

SED command for read and write to different files

Hi I need some help on SED command I am writing a shell script which does the following: 1. Read one line at a time from a file abc.txt which has millions of lines 2. Prefix each line read with some text " 3. Post fix each line read with a quote " 4. Write the new modified... (11 Replies)
Discussion started by: gaurav_1711
11 Replies

5. Shell Programming and Scripting

Find all files with group read OR group write OR user write permission

I need to find all the files that have group Read or Write permission or files that have user write permission. This is what I have so far: find . -exec ls -l {} \; | awk '/-...rw..w./ {print $1 " " $3 " " $4 " " $9}' It shows me all files where group read = true, group write = true... (5 Replies)
Discussion started by: shunter63
5 Replies

6. Programming

read/write files

Hi all, I have a problem with some read/write functions. I have a .bin file which contains a lot of structures as follows: struct alumno { char id; char apellido1; char apellido2; char nombre; float nota1p; float nota2p; float notamedia; char photofilename; }; What I have... (3 Replies)
Discussion started by: Attenea
3 Replies

7. IP Networking

read/write,write/write lock with smbclient fails

Hi, We have smb client running on two of the linux boxes and smb server on another linux system. During a backup operation which uses smb, read of a file was allowed while write to the same file was going on.Also simultaneous writes to the same file were allowed.Following are the settings in the... (1 Reply)
Discussion started by: swatidas11
1 Replies

8. Shell Programming and Scripting

How to read and write last modified timestamp to files?

Need help reading file last modified date in format: Filename (relative path);YYYYMMDDHHMMSS And then write it back. My idea is to backup it to a text file to restore later. Checked this command but does not work: Getting the Last Modification Timestamp of a File with Stat $ stat -f... (5 Replies)
Discussion started by: Tribe
5 Replies

9. UNIX for Beginners Questions & Answers

GPS Device not able to read xml files

Hi, new to Forum and I am not knowledgeable on any coding/encrypting or xml. Short version of my problem is this; My wife bought me a golf GPS unit years ago and the company was bought out by Callaway Golf and eventually discontinued. They dropped all support and website servers. This unit... (14 Replies)
Discussion started by: raidercruz
14 Replies

10. Shell Programming and Scripting

Read and write operations on files.

Dears. kindly guide !!! I have data, which is delimited by | . it should contain 26 columns, but one column data contain | makes few row to 27 columns. I want to find rows have 27 columns and then concatenate the specific columns to single column to make it 26 columns. Kindly help, Can... (3 Replies)
Discussion started by: sadique.manzar
3 Replies
NG_DEVICE(4)						   BSD Kernel Interfaces Manual 					      NG_DEVICE(4)

NAME
ng_device -- device netgraph node type SYNOPSIS
#include <netgraph/ng_device.h> DESCRIPTION
A device node is both a netgraph node and a system device interface. When a device node is created, a new device entry appears which is accessible via the regular file operators such as open(2), close(2), read(2), write(2), etc. The first node is created as /dev/ngd0, all subsequent nodes /dev/ngd1, /dev/ngd2, etc. HOOKS
A device node has a single hook with an arbitrary name. All data coming in over the hook will be presented to the device for read(2). All data coming in from the device entry by write(2) will be forwarded to the hook. CONTROL MESSAGES
The device node supports one non-generic control message: NGM_DEVICE_GET_DEVNAME Returns device name corresponding to a node. SHUTDOWN
This node shuts down upon receipt of a NGM_SHUTDOWN control message, or upon hook disconnection. The associated device entry is removed and becomes available for use by future device nodes. SEE ALSO
netgraph(4), ngctl(8) HISTORY
The device node type was first implemented in FreeBSD 5.0. AUTHORS
Mark Santcroos <marks@ripe.net> Gleb Smirnoff <glebius@FreeBSD.org> BSD
October 19, 2004 BSD
All times are GMT -4. The time now is 04:04 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy