lix/doc/manual/src/expressions/simple-expression.md
Eelco Dolstra 8d0b311a1c
Get rid of footnotes
Markdown doesn't support them.
2020-07-24 11:43:44 +02:00

24 lines
996 B
Markdown

# A Simple Nix Expression
This section shows how to add and test the [GNU Hello
package](http://www.gnu.org/software/hello/hello.html) to the Nix
Packages collection. Hello is a program that prints out the text “Hello,
world\!”.
To add a package to the Nix Packages collection, you generally need to
do three things:
1. Write a Nix expression for the package. This is a file that
describes all the inputs involved in building the package, such as
dependencies, sources, and so on.
2. Write a *builder*. This is a shell script that builds the package
from the inputs. (In fact, it can be written in any language, but
typically it's a `bash` shell script.)
3. Add the package to the file `pkgs/top-level/all-packages.nix`. The
Nix expression written in the first step is a *function*; it
requires other packages in order to build it. In this step you put
it all together, i.e., you call the function with the right
arguments to build the actual package.