Compile and Run, How Do I?

[joelindo]

I can create a program in C, but I don't know how compile and run it on Pi4B or a PiZeroW.

[bassamanator]

Can you compile and run the C program on a non-RPi linux computer? I imagine the process would be the same. Likely need to use GCC.

[jahboater]

If your program is called "hello.c" then the shortest command is:

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cc hello.c && ./a.out

[W. H. Heydt]

Depends on what resources your program needs...like libraries and such. For instance, here is a small selection from a makefile I have for recompiling my con reg system:

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CC = gcc
INCLUDES = -I/usr/include/mysql
LIBS = -L/usr/lib/mysql -lmariadbclient

all: ddc

ddc.o: ddc.c
        $(CC) -c $(INCLUDES) ddc.c


ddc: ddc.o
        $(CC) -o ddc ddc.o $(LIBS)
        cp ddc /home/ddcadmin/bin
        
clean:
        rm -f ddc*.o ddc

[joelindo]

Sorry about the extra post. I'm new here and quite lost so far. . . I have compiled and run programs only on a Windows machine, never on Linux. I've never worked with Linux before.

[joelindo]

I suppose learning Linux is the next step. . . Does Linux take the text file and compile it by itself?

[DougieLawson]

I suppose learning Linux is the next step. . . Does Linux take the text file and compile it by itself?

No. There nothing in stock Linux that would do that for you (without adding special scripts).

You're running a program to compile source code to object code and link object code to an executable.
The program that does that compilation is cc or gcc (or for C++ you'd run g++ or gpp).

https://medium.com/@salmenzouari/how-to ... 8ab78a5f53

[jahboater]

I suppose learning Linux is the next step. . . Does Linux take the text file and compile it by itself?

No. There nothing in stock Linux that would do that for you (without adding special scripts).

Yes there is, for simple programs anyway.

Just type "make program" and make will deduce how to build it and create the executable for you.

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$ ls
hello.c
$ make hello
cc     hello.c   -o hello 
$ ./hello
Hello world!
$  

as you can see, make has found a matching source file with a ".c" extension, so it uses the C compiler to create the target program.
No makefile or script is needed for a simple program like this.

[dsyleixa123]

the most simple way IMO is using the Geany IDE. It comes already installed with Stretch or Buster (look into the GUI menu) and it provides a convenient text editor for your file, you don't have to mess around with the annoying make/makefile thing. Geany can address the C/C++ compiler gcc which also already preinstalled on the Pi.
For compiling, building, and running you can just write the parameters into Geany's preferences:

compile: gcc -Wall -c "%f"
build: gcc -Wall -o "%e" "%f"
run: „sudo ./%e"

save the settings.

now Geany uses your active source code tab automatically and you can use short-cuts for
compile : [F8]
build: [F9}
run: [F5]
For further questions continue in the C/C++ sub-forum
viewforum.php?f=33&sid=c3510c309cae6a9e3a832e3a42a7309e

[joelindo]

Thanks All! The learning is slow and you've been great.

[GlowInTheDark]

Another cute solution (literal solution to the problem as phrased in the Subject line) is tcc - the tiny C compiler. tcc is very fast; much faster (at compiling) than gcc.

For example:

(Note: As far as I can tell, you can't do this with gcc - and, believe me, I've tried...)
$ tcc -run - <<< 'int main(void) { puts("hello, world"); }'
hello, world
$

tcc is in the Raspbian repos - it runs on x86, x64, or ARM.

tcc is actually pretty cool. It is also possible, with tcc, to write a C program that accepts another C program as input. It will then compile and run that C program (without forking another process; that would be cheating).

Incidentally, as far as I can tell, you can't do both of these tricks at once, though. I.e., you can't use -run with a program that does what is described in the previous paragraph. You have to create an output file and run that.

[jahboater]

tcc is in the Raspbian repos - it runs on x86, x64, or ARM.

And aarch64 on Raspberry Pi OS 64-bit, just tried it.

Great little compiler!

[W. H. Heydt]

All various ways to do what we used to call "compile, load, and blow". (Which was then followed by reading the core dump to find out what went wrong.)

[GlowInTheDark]

All various ways to do what we used to call "compile, load, and blow". (Which was then followed by reading the core dump to find out what went wrong.)

Yeah, that actually points to one of the design goals/ideas behind tcc - that it is good for development (I.e., endless edit/compile/test/repeat cycles) because it compiles fast. The emphasis is on compiling fast, rather than on generating fast (efficient) code. gcc is just the opposite; slow compiler that generates very good code.

It is generally held, in particular, that such a compiler is good for students, since they compile often, but once working, their code is pretty much never used.

[deepo]

Sorry about the extra post. I'm new here and quite lost so far. . . I have compiled and run programs only on a Windows machine, never on Linux. I've never worked with Linux before.

It's quite simple, but in the end you will need to learn Linux to progress. But that can come later.

Log in to your Raspberry Pi, then start the nano editor:

nano helloworld.c
Then type in the hello world code:

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#include <stdio.h>

int main(int argc, char *argv[])
{
        printf("Hello world!\n");
        return 0;
}

Then write the changes to the file using Ctrl+O and exit the editor using Ctrl+X
Then compile the code (the compiler is already installed):
cc helloworld.c
The output of the compilation is in a.out per default, now run it:
./a.out
And you should see:

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Hello world!

As jahboater describes, you can use the -o option to get an executable with the name you desire.

But for larger projects you should look into makefiles or even CMake.

/Mogens

[jahboater]

Yeah, that actually points to one of the design goals/ideas behind tcc - that it is good for development (I.e., endless edit/compile/test/repeat cycles) because it compiles fast. The emphasis is on compiling fast, rather than on generating fast (efficient) code. gcc is just the opposite; slow compiler that generates very good code.

You are supposed to use -O0 for fast debug/test cycles, and turn on optimization as production/release approaches.

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pi@raspberrypi:~ $ time tcc hello.c

real	0m0.027s
user	0m0.020s
sys	0m0.008s
pi@raspberrypi:~ $pi@raspberrypi:~ $ time gcc -O3 hello.c

real	0m0.105s
user	0m0.073s
sys	0m0.032s

TCC is a good bit faster than GCC, but then 105ms is not long to wait (for this trivial program anyway)!

GCC fully supports the latest standards: C18, C++17, and the draft C2x and C++20, which although TCC is very good in this respect, likely will not match.

The -run option is great too, but "gcc hello.c && ./a.out" is easy enough in a script called perhaps "ccr".
Oddly, "gcc hello.c && ./a.out" is faster than running a similar Python program ......explain that!!!

[joelindo]

Sorry for taking so long to respond. Been busy learning on my own, which, along with all your help, has fixed my problem. Thanks again.

[W. H. Heydt]

All various ways to do what we used to call "compile, load, and blow". (Which was then followed by reading the core dump to find out what went wrong.)

Yeah, that actually points to one of the design goals/ideas behind tcc - that it is good for development (I.e., endless edit/compile/test/repeat cycles) because it compiles fast. The emphasis is on compiling fast, rather than on generating fast (efficient) code. gcc is just the opposite; slow compiler that generates very good code.

It is generally held, in particular, that such a compiler is good for students, since they compile often, but once working, their code is pretty much never used.

Yes and no. If you only get one shot at compiling and failing per day (unless you're on especially good terms with the console operators), it tends to make one really check the code to get the most out of each run. On the other hand, more or less immediate feedback has it's advantages as well.

When dealing with student programs, I doubt that you'll see any that take gcc very long to compile. I'd be surprised to see a student program that took long enough to compile to go get a cup of tea.