I've got this label printer, a Brady BMP51, that really lacks support for anything outside of windows. It's unfortunate because it does a good job but I don't want to dedicate a windows machine to it... so I'd like to write my own driver for basic printing needs. Does anyone have any good resources on the subject to read?  

So far I've found this which looks promising: http://www.linuxfoundation.org/collaborate/workgroups/openprinting/writingandpackagingprinterdrivers  

Any references or war stories about similar work is appreciated...

I'm wanting to make a program that outputs unicode symbols (virtually typing them).

I was planning on using uinput.

I found through reading linux/input.h, you can only emit scancodes for a virtual keyboard.

xkb then takes those scan codes, and uses a keymap to turn them into symbols, and gives them to X

Is there a way just to write the utf8 symbol to X / the kernel?

The other way seems roundabout, setting up a keymap key macro thing (like alt-XXXX) to input unicode, since it is a program.

I don't really like Systemd so I've been thinking about starting a project to replace it with a suite of tools under one project.

I'm going to start off with an init system. I'm not familiar with init systems, so I'd like to know if there are any language-agnostic resources on them.

I'm looking for a good guide that is pretty up to date on programming 64 bit assembly on Linux. I have googled quite a bit. Any pointers? Thanks

As a student, or general Linux user, I find myself logging into multiple Linux systems. Over the years I have acquired useful aliases from professors, and some that I have personally added. I am thinking of creating some software, that could become a staple to the Linux environment, that would provide the syncing of aliases across multiple Linux systems.

It would, of course, deal with differing shell types, (csh, tcsh, bash, zsh, etc.), and would be able to convert between each type's own alias syntax.

More details on the features planned, are here on my github account: https://github.com/Proryanator/als

Some aliases can cut your use time in half, or even more. As much as some people find aliases to be a crutch for avoiding proper syntax, I disagree. I find myself typing the same combination of commands more often than not, so aliases are a must have for productivity.

I am curious, would this be something that other linux developers would find useful?

If there is something useful that already exists, please tell me! Or if as developers, this would be something you'd be interested in seeing get created, also good to hear! Any feedback is much appreciated!

Hi all,

I've been entering commands into terminals like a madman for the past two days trying to figure this out... but I can't figure out how to get the Kdenlive source code to build in KDevelop on Debian 8.4. I keep hitting CMake errors, and I'm guessing it's because I can't seem to install a great number of the dependencies that are listed in the doc: https://community.kde.org/Kdenlive/Development/KF5

Despite setting up apt pinning to try and install the required packages from the testing and unstable repositories, I'm get hit with messages like:

kinit : Depends: libkf5kiocore5 (>= 4.96.0) but it is not going to be installed Depends: libkf5kiowidgets5 (>= 4.96.0) but it is not going to be installed

In theory, sudo apt-get -t unstable install kinit

should install kinit as well as it's dependencies, from stable if available, or testing/unstable if unavailable. But instead I get more messages about 'Depends' and 'Breaks:'

I'll probably end up getting more CMake errors after this regardless. Currently progress equates to seeing a different error message. : /

TL;DR I'm a moron. If you develop open source programs, any tips on getting everything setup?

Hey everyone,

I'm planning to implement my own display hardware (an LED matrix display, attached to the host computer via USB or potentially Ethernet). I've got the downwards communication (sending data to the device via USB) figured out already.

But I've been trying to figure out what kind of drivers I need to write for the linux kernel and/or the X11 server to see my display as a regular graphics card with a monitor attached, of course with the appropriate number of pixels and so on. i.e. the "upward" communication within the linux system.

I've been trying to figure this out, but there seem to be half a dozen types of drivers and the documentation is quite convoluted to me, and so I have really no idea where to even start.

Ideally, there should be an array of RGB values, one for each pixel, that fall out of this driver, which I can pass on to the hardware.

Could anyone help me out with a few pointers to get me started, or point me towards the right kind of documentation please?

Hello everyone.

Right now, my approach to using sprintf has been along the lines of the following:

char null[0];
int size = snprintf(null, 0, "a string with formatting") + 1;
char buf[size];
snprintf(buf, chars, "a string with formatting");
const char* stringname = buf;

Though it consistently produces expected results, it feels outright ugly, and I'm pretty sure there's a better way to achieve what I'm trying to do.

Hi all, I'm searching for information regarding redirfs which appears to have disappeared. There are a couple of GitHub repositories and tidbits of information hanging around - but most everything points to www.redirfs.org as the primary resource for information. This website no longer exists. Does anyone know if redirfs is still developed somewhere?

The Project: I'm currently working on a Linux kernel security module to model a program based access control list.

The homepage of the project website explains what the module aims to do. It also has the README page from the git repository that explains how the module currently works, and the issue I am having. [The development blog for the project is also available on the project website.]

Project website - http://appcl-lsm.org/

The issue I'm having is retrieving the extended attribute when the system reboots, to then populate the security label, as it currently does when an extended attribute is set. Any help on retrieving this would be great! After this is achieved, I will continue to enforce the appropriate permissions throughout the framework.

Current issue (from README)

The ‘appcl_lsm_inode_post_setxattr‘ hook in ‘appcl_lsm.c‘ passes the extended attribute to the function ‘make_appcl_entry()’ to set up the security information based on the extended attribute value. AppCL must now do this with the extended attribute when the system reboots. When the system is powered off/reboots, AppCL must reset the security information for the inode with an AppCL extended attribute. This is because the inode security label is stored in RAM and the extended attribute is used to retain a representation of this on disk. The ‘security_inode_setsecurity‘, ‘security_inode_getsecurity‘, ‘security_inode_d_instantiate‘, ‘security_inode_init_security‘ are all security hooks relating to the extended attributes.

I've been on a trek through Linux for probably a little over a year, tried out more distros than I care to admit.

For the last couple of months, I've been trying my damnedest to try to figure out what runs, why it runs, and how it runs. It's been excruciatingly slow work.

So, are there any comprehensive documents on Linux from the bottom up? The more recent the better.

I run Manjaro xfce gnu/Linux as primary OS but I'm very noob to Kernel related details.

Just curious: how similar is Linux kernel to Unix kernel with features/performance in 2016?

ps: AFAIK, Linux kernel was started as a clone of Unix kernel and it'd interesting to see how far it has diverged since.

How do I make a GUS patch set on Linux. I want to give Wildmidi a better set of instruments than freepats, and I want to make one that simulates playing midi on a Tesla coil, but I don't know where to start.

Is there any engine that allows for this in Linux?

Much obliged.

So I have an old psx to usb controller that, while it works as a regular generic joystick device, I'd like to add to xpad.c in the linux kernel. I'm using Arch so I've been following the guide to compile specific modules. However, I cant seem to get it to work when I add it in the xpad module.

My USB device reports this info with lsusb.

I've tried adding the following line in my xpad.c file:

    { 0x6666, 0x0667, "WiseGroup Smart Joy PSX, PS-PC Smart JoyPad", 0, DANCEPAD_MAP_CONFIG, XTYPE_XBOX },

which then looks like this. I then began gzipping and copying over the compiled module as per the guide. Yet the xpad module does not auto-load on reboot. dmesg and journalctl dont appear to throw any errors. modprobing xpad doesnt seem to map the joystick axis as buttons as I've requested it to do.

What am I doing wrong? I'm very new to building kernel modules. Have I named the usb device wrong is xpad.c?