Bash-C Hello World: Compile and run a C program from a single Bash script

bash_c_example.sh

#!/bin/bash
# bash_c_example.sh

# Directory to store the C source file and the executable
EXAMPLES_DIR="$HOME/bash_c_examples"

# Ensure the directory exists, create it if not
mkdir -p "$EXAMPLES_DIR"

# Check if hello_world.c and hello_world executable already exist
if [[ -f "$EXAMPLES_DIR/hello_world.c" && -x "$EXAMPLES_DIR/hello_world" ]]; then
    # Run the existing executable
    echo "(Running existing hello_world executable)"
    "$EXAMPLES_DIR/hello_world"
else
    # Define the C code with "Hello, World!" inside a docstring
    CODE=$(cat <<EOF
#include <stdio.h>

int main() {
    printf("\\nHello, World!\\n\\n");
    return 0;
}
EOF
)

    # Create a C source file with the defined code in the specified directory
    echo "$CODE" > "$EXAMPLES_DIR/hello_world.c"

    # Change directory to the examples directory
    cd "$EXAMPLES_DIR" || exit

    # Compile the C source file using GCC
    gcc -o hello_world hello_world.c

    # Run the compiled executable
    echo "(Running newly compiled hello_world executable)"
    ./hello_world
fi

make executable:

$ chmod +x bash_c_example.sh

run it the first time:

$ ./bash_c_example.sh

example output:

(Running newly compiled hello_world executable)

Hello, World!

run it a second time:

$ ./bash_c_example.sh

(Running existing hello_world executable)

Hello, World!