how can i create a device like /dev/zero?

noone234 · 06-12-2012, 09:19 AM

Hello,
how can write a device like /dev/zero that willl output instead of zeroes ones and will be /dev/one.
Also where can i find /dev/zero source code?
thans.

pan64 · 06-12-2012, 11:20 AM

have you heard about the program called yes?

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273 · 06-12-2012, 11:49 AM

I was under the impression that /dev/zero, like /dev/null, was an output-only thing?

noone234 · 06-12-2012, 11:59 AM

what is the program Yes? and yeah they are an output devices.. what it has to do wuth the question?
edit: yes doesnt work out for me.. i want to create an actual device

pan64 · 06-12-2012, 12:40 PM

yes is not a device, but a simple program.
Here is a tutorial on creating a basic char device: http://learninglinuxkernel.com/Basic...Driver_07.html

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noone234 · 06-12-2012, 02:49 PM

"yes" doesnt workout for me i want to create a device similliar to /dev/zero that will output 1's

noone234 · 06-14-2012, 10:01 AM

does anyone knows where /dev/zero source code is located?

pan64 · 06-14-2012, 11:38 AM

I gave you a link about how to create a simple device. Have you tried?

2ck · 06-14-2012, 11:39 AM

Quote:

Originally Posted by 273

I was under the impression that /dev/zero, like /dev/null, was an output-only thing?

Well, you can write to them--they're just no-error data sinks. /dev/null doesn't do output though which is kinda why we like /dev/zero which you can read null bytes from.

noone234, what you want is to create a character device as pan64 indicated. A complete test program is provided at the end of the linked page.

Please mark this thread as solved if you are satisfied with that answer.

Edit:
Realized input/output might be confusing. By output I mean "read-from".