Chapter 2. Preparing software for RPM packaging

This document features three versions of the Hello World program written in three different programming languages:

Each version is packaged differently.

These versions of the Hello World program cover the three major use cases of an RPM packager.

#!/bin/bash

printf "Hello World\n"

#!/usr/bin/python3

print("Hello World")

#include <stdio.h>

int main(void) {
    printf("Hello World\n");
    return 0;
}

Natively compiled software is software written in a programming language that compiles to machine code with a resulting binary executable file. Such software can be run stand-alone.

RPM packages built this way are architecture-specific.

If you compile such software on a computer that uses a 64-bit (x86_64) AMD or Intel processor, it does not execute on a 32-bit (x86) AMD or Intel processor. The resulting package has architecture specified in its name.

Some programming languages, such as bash or Python, do not compile to machine code. Instead, their programs' source code is executed step by step, without prior transformations, by a Language Interpreter or a Language Virtual Machine.

Software written entirely in interpreted programming languages is not architecture-specific. Hence, the resulting RPM Package has the noarch string in its name.

Interpreted languages are either Raw-interpreted programs or Byte-compiled programs. These two types differ in program build process and in packaging procedure.

This section shows how to build the cello.c program written in the C language into an executable.

cello.c

#include <stdio.h>

int main(void) {
    printf("Hello World\n");
    return 0;
}

This section shows how to byte-compile a program written in Python and raw-interpret a program written in bash.

#!/usr/bin/python3

print("Hello World")

#!/bin/bash

printf "Hello World\n"

Packagers often use the install command in cases when build automation tooling such as GNU make is not optimal; for example if the packaged program does not need extra overhead.

The install command is provided to the system by coreutils, which places the artifact to the specified directory in the file system with a specified set of permissions.

The following procedure uses the bello file that was previously created as the arbitrary artifact as a subject to this installation method.

Using the make install command is an automated way to install built software to the system. In this case, you need to specify how to install the arbitrary artifacts to the system in the Makefile that is usually written by the developer.

This procedure shows how to install a build artifact into a chosen location on the system.

The bello project implements Hello World in bash. The implementation only contains the bello shell script, so the resulting tar.gz archive will have only one file apart from the LICENSE file.

This procedure shows how to prepare the bello project for distribution.

For more information about the example source code written in bash, see Section 2.1.1.1, “Hello World written in bash”.

The pello project implements Hello World in Python. The implementation only contains the pello.py program, so the resulting tar.gz archive will have only one file apart from the LICENSE file.

This procedure shows how to prepare the pello project for distribution.

For more information about the example source code written in Python, see Section 2.1.1.2, “Hello World written in Python”.

The cello project implements Hello World in C. The implementation only contains the cello.c and the Makefile files, so the resulting tar.gz archive will have two files apart from the LICENSE file.

This procedure shows how to prepare the cello project for distribution.

For more information about the example source code written in C, see Section 2.1.1.3, “Hello World written in C”.