Steps to create and run a program

1. Write the source: Use an editor to write valid C code. Save the file with the .c extension, such as hello.c.
2. Preprocess: The preprocessor handles instructions such as #include and #define. Header information and macro replacements are prepared.
3. Compile: The compiler checks the C code and translates it for the selected target. Correct the reported errors.
4. Assemble: In a usual toolchain, assembly instructions are converted into object code. Some implementations combine these stages.
5. Link: The linker combines the object files and required library code. It produces an executable program.
6. Run: The operating system loads the executable. In a hosted C program, execution starts at main.

Object code and executable code

An object file contains translated code, but it may still need code from other files or libraries. An executable is the linked program prepared for the target environment. A successful compilation can still be followed by a linking error, for example when a required function definition is missing.

Types of errors

1. Syntax error: The code breaks a language rule, such as a missing semicolon. The compiler reports the problem.
2. Link error: The linker cannot find a required definition or compiled component.
3. Runtime failure: A problem occurs while the program is running, such as an invalid memory access.
4. Logical error: The program runs but uses the wrong steps or formula. For example, it subtracts marks instead of adding them.

Compile and run commands

With GCC installed, use the command below. On Linux or macOS, run ./hello. In Windows PowerShell, create hello.exe and run .\hello.exe. Read warnings as well as errors.

gcc -std=c11 -Wall -Wextra -pedantic hello.c -o hello

Reference tables

Diagram or flowchart

C program and output

/* CodeBhavya | PPS AR25 | Learning example */
#include <stdio.h>
int main(void)
{
    puts("Hello, CodeBhavya!");
    return 0;
}

Hello, CodeBhavya!

Key points

• A .c file is source, not a native executable.
• Warnings deserve attention even when an executable is produced.