Documentation: update build system documentation and prerequisites in preparation for next commit

README.md

@@ -22,13 +22,19 @@ Immediate goals:
 
 ### Prerequisites:
 
-This project requires bash and a C++20 compiler.
+Build dependencies:
 
-The project setup requires wget or curl, gzip, and tar.
+- bash
+- a C++ 20 compiler
 
-Additional requirements for building dependencies:
+Setup dependencies:
 
-- sockpp: a C compiler, CMake
+- wget or curl
+- gzip
+- sha256sum (or NetBSD's sha256, hashalot's sha256 will not work)
+- tar
+- a C compiler (for sockpp)
+- CMake (for sockpp)
 
 **For people using other shells than bash:** You need to at least have bash
 installed to use the scripts, but using it as your shell while working on

doc/build_system.md

@@ -76,3 +76,20 @@ Also removes the endianness header and the endianness check binary.
 
 Removes and re-creates `dependencies/` and prunes the download cache of files
 that either have been corrupted or are no longer used.
+
+# lib
+
+This is not a script you are supposed to run. It's a library that contains
+some functions for the other scripts to work properly on all platforms.
+
+Features it provides:
+
+- `$WAIT_ANYWAY`: a variable containing the `wait` command if `SINGLE=yes`
+is set.
+- `$CXX_WITH_FLAGS`: deals with `CXX` and `CXXFLAGS` environment variables
+so it can be used as a generic compiler command
+- function `check_sha256`: deals with `sha256sum` and NetBSD's `sha256`
+- function `remove`: better verbosity
+- function `create_directory`: alternative to `mkdir -v` because that's not
+available on some systems
+- function `create_file`: the same but for files