When i type the command gcc filename.c a new file 'a.exe' is created, then i have to run a.exe to get my program to run.
Is there a way just to type one command to run my program or can you run a C program without having a new .exe file being created?
I use gcc version gcc (MinGW.org GCC-6.3.0-1) 6.3.0
(Complete beginner with C)
You can't run the .c file directly - you have to compile it into an executable (using gcc or whatever compiler). However, you don't have to compile it every time you want to run it - you only have to compile it after first creating it and after you make any changes. So you can run gcc once, then run a.exe multiple times.
You can name the executable something other than a.exe if you wish using the -o option:
gcc -o prog filename.c
./prog
You could make a .bat file that does everything for you. For example:
build.bat
gcc %1.c -o %1.exe
%1.exe
This will build and run the file for you:
build hello
will compile and run hello.exe for you.
I am new to C. Here is my "Hello, World!" program.
#include <stdio.h>
int main(void)
{
printf("Hello, World!\n");
return 0;
}
After I try to run it using Terminal it says:
/Users/macbook/Desktop/peng/Untitled1
-bash: /Users/macbook/Desktop/peng/Untitled1: Permission denied
Why?
First save your program as program.c.
Now you need the compiler, so you need to go to App Store and install Xcode which is Apple's compiler and development tools. How can you find App Store? Do a "Spotlight Search" by typing ⌘Space and start typing App Store and hit Enter when it guesses correctly.
App Store looks like this:
Xcode looks like this on App Store:
Then you need to install the command-line tools in Terminal. How can you start Terminal? You need to do another "Spotlight Search", which means you type ⌘Space and start typing Terminal and hit Enter when it guesses Terminal.
Now install the command-line tools like this:
xcode-select --install
Then you can compile your code with by simply running gcc as in the next line without having to fire up the big, ugly software development GUI called Xcode:
gcc -Wall -o program program.c
Note: On newer versions of OS X, you would use clang instead of gcc, like this:
clang program.c -o program
Then you can run it with:
./program
Hello, World!
If your program is C++, you'll probably want to use one of these commands:
clang++ -o program program.cpp
g++ -std=c++11 -o program program.cpp
g++-7 -std=c++11 -o program program.cpp
First make sure you correct your program:
#include <stdio.h>
int main(void) {
printf("Hello, World!\n"); //printf instead of pintf
return 0;
}
Save the file as HelloWorld.c and type in the terminal:
gcc -o HelloWorld HelloWorld.c
Afterwards, just run the executable like this:
./HelloWorld
You should be seeing Hello, World!
A "C-program" is not supposed to be run. It is meant to be compiled into an "executable" program which then can be run from your terminal. You need a compiler for that.
Oh, and the answer to your last question ("Why?") is that the file you are trying to execute doesn't have the executable rights set (which a compiler usually does automatically with the binary, which let's infer that you were trying to run the source code as a script, hence the hint at compiling.)
This is Working in 2019
By default, you can compile your name.c using the terminal:
cc name.c
And if you need to run, just write
./name.out
To do this:
Open the terminal
Type in the terminal: nano ; which is a text editor available for the terminal. When you do this, something like this would appear.
Here you can type in your C program
Type in Ctrl + X → which means to exit.
save the file by typing in Y to save the file
Type the file name; e.g., helloStack.c (don't forget to add .c)
When this appears, type in gcc helloStack.c
And then ./a.out: this should give you your result!
For compiling a C program on your latest macOS, just type the following in the terminal after saving the file with a .c extension and on reaching the path where the file is saved:
cc yourfilename.c
Once you have checked all the errors after compilation (if any), type the following for executing the code:
./a.out
These commands are tested on macOS v10.14 (Mojave) and are working perfectly fine.
To compile a C program in macOS, simply follow the below steps
Using the cd command in terminal, go to your C program location and then type the command present below:
make filename
then type
./filename
The answer is chmod 755 hello - it makes the file executable... I had same problem on macOS, which is now solved.
nano hello.c
make hello
chmod 755 hello
Then you run it by ./hello
clang --version
Output:
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin15.6.0
Nothing was installed. nano make (clang) chmod - all inside macOS already.
On Mac, GCC (executable gcc) is installed by default in /usr/local/bin.
To run C:
gcc -o tutor tutor.c
First you need to install a GCC compiler for Mac (google it and install it from the Internet)
Remember the path where you are storing the C file
Go to Terminal and set the path
E.g., if you have saved in a new folder ProgramC in the Document folder.
Then type this in Terminal:
cd Document
cd ProgramC
Now you can see that you are in folder where you have saved your C program (let you saved your program as Hello.c)
Now compile your program
make Hello
./hello
I am having trouble compiling and running my C program. What are the commands?
My code is:
#include <stdio.h>
int main(){
printf("Hello World!\n");
exit(0);
}
I tried compiling with
gcc -o hello.c
only to be unsuccessful. I am using a Mac terminal, if that matters.
In gcc, option -o is used to specify a custom output filename. The immediate next argument should be the file name.
-o file
Place output in file file. This applies to whatever sort of output is being produced, whether it be an executable file, an object file, an assembler file or preprocessed C code.
A simple revised command will be
gcc -o hello hello.c
where, hello is the name of the binary.
You can check the online gcc manual for more info.
I'm trying to compile my first "Hello World" application using GCC (build-on clang and stand-alone GCC-4.9.2) without any success:
OS version is OS X Yosemite 10.10.2.
I'm using the following code (main.c):
#include <stdlib.h>
#include <stdio.h>
int main (){
printf("Hello World!");
getchar();
return 0;
}
Then I compile it in terminal with a command (clang shipped with XCode):
gcc -o hello -c main.c
As a result I got following error whe running compiled hello file:
MBP-Andrii:cTest andrii$ gcc -o hello -c main.c
MBP-Andrii:cTest andrii$ hello
-bash: /Users/andrii/avrTest/cTest/hello: Permission denied
If I change the permissions for hello file to 777 and a new error again:
MBP-Andrii:cTest andrii$ chmod 777 hello
MBP-Andrii:cTest andrii$ hello
Killed: 9
MBP-Andrii:cTest andrii$
The same thing happens with stand-alone GCC-4.9.2.
I guess It might be something related to the output binary format or some missing flags for compiler.
Remove the -c from the command you're using to compile the application.
The -c tells the compiler to only compile and assemble but not link. You are not actually creating an application when using -c.
See the GCC Manual:
-c
Compile or assemble the source files, but do not link. The linking stage simply is not done. The ultimate output is in the form of an object file for each source file.
By default, the object file name for a source file is made by replacing the suffix ‘.c’, ‘.i’, ‘.s’, etc., with ‘.o’.
Unrecognized input files, not requiring compilation or assembly, are ignored.
Try executing it by typing ./hello
I have GCC running on my Ubuntu operating system. I wrote a small program in C and tried compiling it. Its output was an a.out file like it would do on Windows. How can I make it put out a Linux executable?
a.out is the executable (assuming you've done full compilation rather than just generation of object files but that's the most likely case). To run it, use (from a shell):
./a.out
If you want to give it a different name, simply rename it, or better:
gcc -o actualname myprog.c
to get an executable called actualname which is then run (of course) with:
./actualname
See the following transcript:
pax> cat testprog.c
#include <stdio.h>
int main (void) { printf("Hi.\n\n"); return 0; }
pax> gcc testprog.c ; ./a.out
Hi.
pax> gcc -o xyzzy testprog.c ; ./xyzzy
Hi.
Suppose your C file is f.c.
gcc f.c gives the a.out executable, and you can run it in a terminal as ./a.out.
gcc f.c -o myprog gives myprog as the executable, and you can run it in a terminal as ./myprog.
It is a Linux executable. a.out files (actual a.out format, not files named a.out by default) cannot be executed on Windows.
In both cases, most likely you get a standard executable usable in the local system, but named a.out. On Linux it's an ELF file.