Build a Linux executable using GCC

Question

I'm using Ubuntu 8.10 (Intrepid Ibex) and compiling C++ files with GCC, but when I compile, gcc makes an a.out file that is the executable. How can I make Linux executables?

What is the difference for you between an executable and a Linux executable ? — Ben, Jul 17 '09 at 00:38
can you clarify? The `*.out` files are the executables. Do you need another type of executables? — notnoop, Jul 17 '09 at 00:39
Nathan, the 'a.out' name is a historical artifact, from the earliest Unix compilers. See the Wikipedia article on the subject: http://en.wikipedia.org/wiki/A.out — quark, Jul 17 '09 at 01:05
@notnoop: It's just `a.out`, not `*.out`. (Greetings from the future!) — Keith Thompson, Apr 01 '18 at 20:52
`a.out` should already be executable. No need to do anything else. Just run with `./a.out` — Max MacLeod, Jul 04 '19 at 16:20
Related: *[How can I compile and run C/C++ code in a Unix console/Mac terminal?](https://stackoverflow.com/questions/221185/)* — Peter Mortensen, Apr 03 '22 at 13:42

score 23 · Accepted Answer · edited Apr 03 '22 at 13:36

23

That executable is a "Linux executable" - that is, it's executable on any recent Linux system. You can rename the file to what you want using

rename a.out your-executable-name

or better yet, tell GCC where to put its output file using

gcc -o your-executable-name your-source-file.c

Keep in mind that before Linux systems will let you run the file, you may need to set its "executable bit":

chmod +x your-executable-name

Also remember that on Linux, the extension of the file has very little to do with what it actually is - your executable can be named something, something.out, or even something.exe, and as long as it's produced by GCC and you do chmod +x on the file, you can run it as a Linux executable.

edited Apr 03 '22 at 13:36

Peter Mortensen

30,738
21
105
131

answered Jul 17 '09 at 00:39

Tim

59,527
19
156
165

4

Doesn't gcc (in fact the linker it calls) already set the executable bit in its output file? – CesarB Jul 17 '09 at 00:58
2

@CesarB: Yes, the gcc call makes 'your-executable-name' executable by default. – quark Jul 17 '09 at 01:04
1

Some systems might have a `rename` command, but `mv` is the usual way to rename a file. – Keith Thompson Apr 01 '18 at 20:52
Conversely it may or may not set too much: `-rwxrwxr-x`. – Peter Mortensen Apr 03 '22 at 13:33

score 4 · Answer 2 · edited Apr 03 '22 at 13:39

4

To create an executable called myprog, you can call gcc like this:

gcc -c -o myprog something.c

You could also just rename the *.out file gcc generates to the desired name.

edited Apr 03 '22 at 13:39

Peter Mortensen

30,738
21
105
131

answered Jul 17 '09 at 00:39

sth

222,467
53
283
367

score 3 · Answer 3 · edited Apr 03 '22 at 13:39

3

That is the executable. If you don't like a.out, you can pass an -o flag to the compiler. If the executable isn't marked with an executable bit, you need to do so yourself:

chmod u+x ./a.out
./a.out

edited Apr 03 '22 at 13:39

Peter Mortensen

30,738
21
105
131

answered Jul 17 '09 at 00:37

EightyEight

3,430
4
36
67

The *.out file already is an executable, but how i can build a native Linux executable, linux native executables don't have extensions. – Nathan Campos Jul 17 '09 at 00:40
5

In linux, extensions don't matter. You can just rename the file to anything you like. – notnoop Jul 17 '09 at 00:41
When the problem is permition i know. Thanks! – Nathan Campos Jul 17 '09 at 00:52

Build a Linux executable using GCC

3 Answers3