Linux - NewbieThis Linux forum is for members that are new to Linux.
Just starting out and have a question?
If it is not in the man pages or the how-to's this is the place!
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Get a virtual cloud desktop with the Linux distro that you want in less than five minutes with Shells! With over 10 pre-installed distros to choose from, the worry-free installation life is here! Whether you are a digital nomad or just looking for flexibility, Shells can put your Linux machine on the device that you want to use.
Exclusive for LQ members, get up to 45% off per month. Click here for more info.
What are linux headers or kernel headers. What do they do and what are they for?
When compiling a new kernel do you need to compile new the headers also?
a header tells other software what functions exist in other preexisting code on the system. if you need to use a function in an external library to your own code then rather than needing the source code of the other package all you need is a declaration of what exists within that other code, not the code itself. among other things, that's a header.
What are linux headers or kernel headers. What do they do and what are they for?
When compiling a new kernel do you need to compile new the headers also?
You don't "compile headers"....headers give the compiler information that it needs to compile from the source code.
Another good definition of a header: A place to define things so you don't have to do it in your code.
The best way to get a feel for how this works would be to write and compile the ever-popular "Hello World" program in C.
You don't "compile headers"....headers give the compiler information that it needs to compile from the source code.
Another good definition of a header: A place to define things so you don't have to do it in your code.
The best way to get a feel for how this works would be to write and compile the ever-popular "Hello World" program in C.
Don't some source codes require the headers for the new kernel in order to compile?
I have an hsf modem. Though you do not install the driver from source, I seem to recall that I could not install the linuxant hsf modem driver with the new kernel. Perhaps there was a different issue?
A "header" file is a source code file that is "included" in other source files. Structure, type, function and macro definitions are placed in these distinct files so that they may be shared with other source code that relies on these common definitions.
The kernel source code, being a critical component of a system, defines many types, structures, functions and macros for its own use. In order to ensure correct argument passing and data size, the kernel makes these include (aka: headers) files available not only for itself, but also for user programs and device drivers. Any source code that needs to interact with the system typically requires some include files defined for building the kernel itself. Some include files are "included" in user source code merely for a single macro, while other source code may use many of the objects defined in an include file.
An addition to kernel include files, there are also the libc runtime include files, that define the objects defined by the C runtime standard(s). These are some of the most commonly included header files.
Finally, there are other libraries installed and available, such as the openssl or BerkeleyDB libraries, which also makes their header files available to programs that wish to interact with these library.
Headers are simply include files written in C, they are needed when compiling kernel modules along with the kernel source code. Headers are not really "compiled" in and of themselves, but they are needed in the compiling of kernel modules when you could say they are compiled. Also, it's NOT recommended that you upgrade your kernel headers, doing so will cause problems. Usually these are only upgraded when also upgrading glibc.
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.