Some *nix questions

[smp]

Okay, I keep hearing this type of stuff and I just know that I whatever I read will require some sort of programming knowledge to understand, maybe I'm being naive in my attempt to get the hang of this since I'm not a comp-sci major, or a programmer.

What is

1) a.out and elf?
2) libc4 libc5 etc?
3) GCC is a compiler, I know, but what is ncurses?

Just stuff like that, how do you all know (those that do) this stuff? How do did you wrap your head around the concepts that are native to *nix in the first place? It seems that my learning curve is longer, steeper and harder than anyone elses

 

[DaHitman]

Ok... I will take a shot at these...

What is

1) a.out and elf?

They are formats for how an executable is stored on disk... more of a file format... sort of if there was 2 ways to format the contents of a .exe file... for a user...its not important.. a.out is an older standard that is not used much at all, and elf is the newer standard that everyone uses. Everyone moved to elf several years ago because it works with dynamic linking better, and allows programs to share memory easier. But, these days its nothing more than answer to triva questions and not important.

2) libc4 libc5 etc?

Different version of the C library. libc is the main sort of function calls that are used by C programs... Its the library that stores the basic c programming funnctions like read(), printf() etc..

See??...


This is only important because some programs are compiled against different versions.. the cool think about *NIX is you can have multiple versions of the same library on a system and have programs run that required either versions, and they don't interfere with each other.. this is one thing that Windows really screwed up... in windows a new program that required a newer library overwrites the older library and lots of times breaks compatibility with programs based on the older version (This is what DLL Hell means) ... NIX doesnt have that problem.

3) GCC is a compiler, I know, but what is ncurses?

ncurses, is a library which provides a programmer a simple to use interface which allows them to do character based GUI's in text mode screens... makes a text interface for a program much nicer with input boxes, buttoms, pop-ups etc..

Just stuff like that, how do you all know (those that do) this stuff? How do did you wrap your head around the concepts that are native to *nix in the first place? It seems that my learning curve is longer, steeper and harder than anyone elses

Nah... most of this stuff is "programmer" stuff, and you really don't have to know much of anything about it as a NIX user... I used NIX for many years before I picked this stuff up...

 

[hobgadling]

Originally posted by: smp
1) a.out and elf?

These are two different binary types, I'm not entirely sure what the difference is, but I believe it has somthing to do with what glibc they are compiled against.

2) libc4 libc5 etc?

These are different versions of the GNU C Library. Check the link for more info.

3) GCC is a compiler, I know, but what is ncurses?

Ncurses is a library that you can use to create graphical looking programs at a terminal or tty.

Just stuff like that, how do you all know (those that do) this stuff? How do did you wrap your head around the concepts that are native to *nix in the first place? It seems that my learning curve is longer, steeper and harder than anyone elses

No, its that bad for everyone. It takes lots of time, espically coming from a Windows environment. For straight up working in the environment, I suggest searching out Running Linux and/or Linux in a Nutshell from O'Reilly. If you're interested in programming, I'm sure there's lots of books, but for a beginner I've had lots of luck from Beginning Linux Programming from Wrox. HTH.

--Hob, Windows free for 2+ years and still a Linux newbie

 

[n0cmonkey]

Originally posted by: DaHitman
Ok... I will take a shot at these...

What is

1) a.out and elf?

They are formats for how an executable is stored on disk... more of a file format... sort of if there was 2 ways to format the contents of a .exe file... for a user...its not important.. a.out is an older standard that is not used much at all, and elf is the newer standard that everyone uses. Everyone moved to elf several years ago because it works with dynamic linking better, and allows programs to share memory easier. But, these days its nothing more than answer to triva questions and not important.

OpenBSD is still on a.out for all but sparc (maybe sparc64 too), I think. Darwin/Mac OS X uses Mach-o. I know there is atleast one more format out there, but I cant think of it offhand... Each has advantages and disadvantages, just dont ask me what they are.