I've a problem with character device mounting. I've a character device module code. Here is the code
Code: /* chardev.c: Creates a read-only char device that says how many times
* you've read from the dev file
*/
#if defined(CONFIG_MODVERSIONS) && ! defined(MODVERSIONS)
#include <linux/modversions.h>
#define MODVERSIONS
[Code]...
i woul like to know if i could get help in writing a charater device driver for communication between two pc's in linux using RS-232 serial port.
View 5 Replies View RelatedI did searched you tube but my results were not great.I have 2 books on KernelProgramming.I feel I need if some where I can get a video tutorial which can help me to understand how to develop a Linux Device driver that will be great.I had a look at Greg Kroah Hartmans video lecture of developing patches on ......I have been reading books and a lot of stuff.So I wish if I could get a video lecture that would be better
View 1 Replies View RelatedI know, I know..."How long is a piece of string"?
I have one of these devices:
[URL]
Of course, it's Windows only, and XP only at that. However, the data that needs transferred between the device and the computer should be fairly basic, unless it offloads a lot of processing to the computer. I'm not a programmer, nor do I play one on TV, but I have written some fairly complicated microcontroller programs and some basic Java GUIs. Besides writing the actual code, how hard is it to do whatever needs done to make a Linux device driver, apart from the code to make the device work?
Is there an easy example of a block device driver I could follow as a guide to write my own module?
View 5 Replies View RelatedHow to do device driver programming in Ubuntu 10.04?
View 2 Replies View RelatedI wrote a small hello world type of character device driver. When I type echo -n "abcdef" > /dev/bond and do a cat /dev/bond then only last "f" of above input abcdef is displayed rest nothing is displayed. I asked this question earlier and some people suggested me some modifications I have done and experimented all that but I am unable to catch the error.
Here is the code
Code:
/* Necessary includes for device drivers */
#include <linux/init.h>
//#include <linux/config.h>
#include <linux/module.h>
[Code].....
I have a user Application for transferring the data from one PC to the other PC using Ethernet Port, can we create a device driver for that ?? that means it should act like a virtual device, if we write data into /dev/some file, it should go the other PC
View 3 Replies View Related1.What character instructd the shell to interpret a special character as an ordinary character?
2.What directory contains some of the utilities available on the system in the form of binary files?
3. What command is used to search the location of a utility?
4. What command is used to instruct the editor to write the file and quit the editor?
5. What key quits the more utility and displays the shell prompt?
6. What command starts a child shell as the super user, taking on root's identity and environment?
7. Which wildcard characters can be used for searching all the files in the system that start with "A"?
8. The user name or login name of the super user is????
[Code]....
i am trying learn to program linux kernel modules and smoothly transition in device driver programming. I have a year and a half worth of programming in C and have been using linux for years!! But my question is how do i compile a module? I got as far as coding it but am stuck as of now.
View 2 Replies View Relatedi studied the program chardev.c from 'The kernel module programming guide'. The text tells me that by doing a :
1. 'cat' the character device is opened.
2. hi > /dev/hello the character device is written into.
now i wanted to know how to 'read' from the character device !
I'm reading linux device drivers,
and I'm creating a scull-like driver.
I alloc a chrdev region
with
alloc_chrdev_region(&dev,minor_number,number_of_devs);
how can i deallocate it ? I tried with
unregister_chrdev_region but it does work only for
statically allocated devices.
i want to deallocate it so that only a single major number is assigned to my driver and
cat /dev/devices | grep $dev_name
returns no more than 1 line.
There are so many system information tools i figure that this one would be in the set. I just can't seen to find it.
View 9 Replies View RelatedI'm trying to install an open source driver BADDRV on Suse 11, x64 system.What I have done:installed kernel source. make. insmod ./BADDRV.ko.On Redhat 5, this just works and I can run the user program that calls open(/dev/BADDRV) and its ioctls.On Suse 11 there is no entry in /dev so I add mknod /dev/BADDRV c 0 0.The user open(/dev/BADDRV) fails with errno 6.(I also tried mknod /dev/BADDRV c 244 0, per suggestion of dmesg. No difference.)There is an rpm provided with the driver. Installing the rpm on Suse 11 works and then the user program works. The only problem with the rpm is that it requires kernel source to be installed, which I can't ask of my customer base.
View 3 Replies View RelatedI am currently using fedora 11 kernel 2.6.29 version, i wanted to write device driver for usb to detect my own device. My project is radio with computer. My fm radio get connected to usb port so i need to write h/w interfacing program.
View 1 Replies View RelatedThe error "USB device 6 (vend/prod 0x603/0xf2) is not claimed by any active driver." is in dmesg every time I connect my Logitech keyboard to my system. I also tried (all with the same error):
- Memory stick
- DVD-burner
- Compaq mouse
I have installed live cd on usb pendrive. Everything works great. How can I find out which device driver it is using? Where are the device driver files stored? How do you specify the device driver when mounting a device?
View 3 Replies View RelatedI have a string like this "/home/test/filename.txt" and i want to delete all character after the last "/". how to do that using sed or awk.
View 5 Replies View RelatedI was reading Kernighan Ritchie book chapter 4 which deals with character pointers.I am not able to understand following different type of declarations
Code:
char aname[][15] = { "Illegal month", "Jan", "Feb", "Mar" };
char amessage[] = "now is the time";
[code]...
i am compiling the following program in linux. it's in c language. after the compilation with gcc when i run the executable file. it asks for input. but when i enter a name. i prints "Segmentation fault" and then terminate the program. can you please help me.
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
[code]....
which is the simplest way to have first and last character cropped out from a string? Something simpler than
Code:
echo $STRING | cut -b 2- | rev | cut -b 2- | rev
I have the following file:
Code:
1 line
...
49 test test=AA:AA:AA:AA:AA=0
I need to substitute on the line number 49, all text until =. I have used the following, but with no actual result.
sed -re '49s/^.+=//' file
and
sed -e '49s/.*[=]//' file
I have a file with one line. I want to check whether the first character is TAB or space, how can i do this.? using "cut" wont as it "bypasses the tab and space characters"
View 3 Replies View RelatedI am trying to check if the 9th character in a file on each line is a v and if so, then print the first word. I've tried a number of variations and am stuck !If it's possible to also check if character position 1 begins with a s in the same awk, that would make it cleaner instead of using egrep.
egrep '^s' file | nawk '{virtual=substr($0,9,1); if ($virtual=="v") {printf "%s", $1}}'
nawk: illegal field $(e)
input record number 1
source line number 1
I believe I have unwanted ' characters left in a 9 element character array that are causing subsequent operations with it to fail. I see wildly differing views on the web on the proper way to flush 'em. It's clearly not as simple as it would appear at first sight. What's currently the best (or else "least deprecated") method?
View 5 Replies View RelatedI am loading variables for cXtXdXsX disk names into a script, and at present I have only accounted for there being 3 characters from c to t. I need to change it to a variable recognition so that it can count any number of charcters such as c1t , c10t , or c100t.
I can then take that information and use it with the following string to strip off the lead characters so as to make the 3 in $substr either a variable or redirect to multiple occurrences of raw based on the count returned.
sub raw {
$substr = substr ($_, 3);
$raw1 = substr ($substr, 0, -4);
$raw = lc($raw1);
}
how to count from the c to the t inclusive so I get 3, 4, 5, etc ...
how to replace last character string. For example
$>export T1=abcde
$>export T2=xyz
how to get result abcdxyz?
I have a string as below
LogFormat "%h %l %u %t "%r" %>s %b "%{Referer}i" "%{User-Agent}i"" combined
Want the above string to be modified as
LogFormat "%h %l %u %D %t "%r" %>s %b "%{Referer}i" "%{User-Agent}i"" combined
inserting %D after %u in the string
I am trying to create a table T having a field F which should be able to store variable-length sequences of "unsigned" characters (8bit values ranging from 0 to 255 (not including 0, including 255)).(MAX_LENGTH) is not working, as it seems to want sequences of 8bit values ranging from 0 to 127 (thus "signed" characters).Can anyone help me by pointing out if there is a type suited for my needs (or if such a type does not exist)?For those familiar to C programming and working with the MySQL client library, I should be able to (successfully) do something along the lines of:
Code:
unsigned char value[] = { 'H', 'E', 'L', 'L', 'O', -1, -128, 'W', 'O', 'R', 'L', 'D' };
unsigned char query[255];
[code]....
i have the following:
Quote:
echo %host%|sed "$s/.$//"
this would remove the Last character of the value assigned to the %host%. for example if my value is: abcd i get abc. but i am not able to assign the output. for example when i do
Quote:
set k=`echo %host%|sed "$s/.$//"`
after doing echo %k i get no output at the command prompt...!! whereas when i just type:
Quote:
echo abcd|sed "$s/.$//"
at the command prompt i get abc. maybe some other ways to Remove the Last character...?