Run a c program

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November 10th, 2012, 07:59 AM

McDuck4

Registered User

Join Date: May 2012

Posts: 4

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Run a c program

Alright first of all, i just spend 30 min making a threat, where i have put screenshots in, so it might would help me to understand, and explain what my problem was. But the site dosent allow me to????? I really dont understand why, especially when some people are newbies, this would be the perfect place for that.

Hello everybody.

I really hope someone can help me.

I just startet on a course, where we have to learn C programming. I downloaded Xocde and followed this installation the installation proces.

I also installede the GRR commandoline toll, and it looks like it is working

I tried to make a hello world, from the page "thenewboston.org", which is running fine from within the Xcode program, but i want to run the program from my terminal on my mac, but i dont know what to write.
my file is called "main.c". Then i go to my terminal and find the folder where my file is, then i write:

g++ main.c (and then it just goes to the next line. Then i write): /.main.c and then i get an answer where it says: "Permission denied"

But what am i doing wrong? I am out of options now, so i hope someone can help me?

Best Regards
Mads

November 10th, 2012, 08:11 AM

bdb

Contributing User

Join Date: Aug 2012

Posts: 156

Time spent in forums: 1 Week 15 h 48 m 11 sec
Reputation Power: 32

The compiler generates an executable file with a different name than the file with the source code.
Probably your compiler generated an executable file named "a.out". Try

Code:

$ g++ main.c
$ ./a.out
<OUTPUT OF YOUR PROGRAM>
$

You can make the compiler output a specific name instead of "a.out". For instance "executable"

Code:

$ g++ main.c -o executable
$ ./executable
<OUTPUT OF YOUR PROGRAM>
$

Also you really, really should enable warnings and mind them, eg

Code:

$ g++ -Wall main.c -o executable
<SOME WARNINGS>
<EDIT CODE TO ADDRESS THE WARNINGS>
$ g++ -Wall main.c -o executable
<NO WARNINGS>
$ ./executable
<OUTPUT OF YOUR PROGRAM>
$

Last edited by bdb : November 10th, 2012 at 08:15 AM.

November 10th, 2012, 08:18 AM

McDuck4

Registered User

Join Date: May 2012

Posts: 4

Time spent in forums: 1 h 1 m 35 sec
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perfect, thank you so much for that :-) it works now. The only thing that is annoying is, that when i get printed "Hello World", it is as the same line that my name of the comuter is. So I write:

Mads-Macbook-pro:test Mads$ get++ main.c -o main
Mads-Macbook-pro:test Mads$./main

and the output is:

Hello WorldMads-Macbook-pro:test Mads$

where i would like it said

Mads-Macbook-pro:test Mads$
Hello World

But i cant do anything about that?

November 10th, 2012, 08:29 AM

bdb

Contributing User

Join Date: Aug 2012

Posts: 156

Time spent in forums: 1 Week 15 h 48 m 11 sec
Reputation Power: 32

Quote:

Originally Posted by McDuck4

... it is as the same line ...

Print a full line within your program

Code:

puts("Hello World"); // puts automatically adds a newline

Code:

printf("Hello World\n"); // add newline manually (the \n)

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