Try to compile your code normally as

gcc test.c

If you get default output file a.exe,then go for

gcc test.c -o test.exe

Do NOT use nano (or another text editor to put your code into) with root/sudo permissions (ie. do not edit with sudo nano, only use nano) if all you are doing is personal stuff that does not need superuser permissions.

Answer

To compile from the command line (assuming yourcode.c is the name of your C file, and program the name of the resulting program after compilation):

1. Write your code in your favorite editor:

   • In the terminal, type nano yourcode.c (assuming you want to use nano);
   • Or use your Leafpad editor (and make sure to know where your file is saved).

2. Back to the terminal, navigate to where your C file is stored. (Reminder: ls to list directory contents, cd to change directory.)

3. Compile your code with gcc -o program yourcode.c.

4. Execute it with ./program. Done!

Bonus method

If you intend on compiling/executing your program quite a lot, you may save yourself time by writing a Makefile. Create this file with Leafpad (or, in terminal, nano Makefile), then write:

all:
    gcc -o program yourcode.c
    ./program

(Make sure you presently use Tab for indents, and not spaces.) Then every time you just type make in the terminal (or make all, but let’s keep things short!), your program will compile and execute.

Testing

Want to make sure your GCC installation works? Copy-paste the following to your terminal:

cd /tmp
cat <<EOF > main.c
#include <stdio.h>

int main() {
    printf("Hello World\n");
    return 0;
}
EOF
gcc -o hello main.c
./hello # Press Enter to execute your program

If it echoes “Hello World”, then you’re good to go.