From 16a793a252e51530bca1b15ee3a0b470929816b4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hana=20Dusi=CC=81kova=CC=81?= <hanicka@hanicka.net>
Date: Fri, 2 Jan 2026 17:45:08 +0100
Subject: [PATCH] [check] make scripts detect presence of GNU sed and use it
 (to make it work on macOS) + update readme for macOS

---
 README.rst            | 19 +++++++++++++------
 tools/check-output.sh |  8 ++++++++
 tools/check-source.sh |  8 ++++++++
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/README.rst b/README.rst
index c737a81a71..b89ce85a4b 100644
--- a/README.rst
+++ b/README.rst
@@ -13,19 +13,26 @@ Get involved:
 - `How to tell if an issue is editorial <https://github.com/cplusplus/draft/wiki/How-to-tell-if-an-issue-is-editorial>`_
 - `How to submit a new issue/defect report <https://isocpp.org/std/submit-issue>`_ for non-editorial issues
 
-More information about the C++ standard can be found at `isocpp.org <http://isocpp.org/std>`_.
+More information about the C++ standard can be found at `isocpp.org <https://isocpp.org/std>`_.
 
----------------------------
-Getting Started on Mac OS X
----------------------------
+------------------------
+Getting Started on macOS
+------------------------
 
-Install the `MacTeX distribution <http://tug.org/mactex/>`_.
+Install the `MacTeX distribution <https://tug.org/mactex/>`_.
 
-If you are on a slow network, you'll want to get the `BasicTeX package <http://tug.org/mactex/morepackages.html>`_ instead,
+If you are on a slow network, you'll want to get the `BasicTeX package <https://tug.org/mactex/morepackages.html>`_ instead,
 then run the following command to install the other packages that the draft requires::
 
    sudo tlmgr install latexmk isodate substr relsize ulem fixme rsfs extract layouts enumitem l3packages l3kernel imakeidx splitindex xstring
 
+Using homebrew on macOS
+=======================
+
+Instead of downloading packages from the internet, you can use the `HomeBrew package manager <https://brew.sh>` to install all that is needed to build the draft and run checks on it:
+
+   brew install mactex gnu-sed
+
 ---------------------------------------
 Getting Started on Debian-based Systems
 ---------------------------------------
diff --git a/tools/check-output.sh b/tools/check-output.sh
index a28d236e0c..290312f9c4 100755
--- a/tools/check-output.sh
+++ b/tools/check-output.sh
@@ -11,6 +11,14 @@ function fail() {
     ! sed 's/^\(.\+\.tex\):/file=\1::/;s/^/::error /' | grep .
 }
 
+# If we detect GNU sed (on macOS installed with brew) then we will use it.
+# Otherwise the script can fail on macOS which ships with BSD sed.
+if command -v gsed >/dev/null 2>&1; then
+	GSED=$(command -v gsed)
+	sed() {
+		${GSED} "$@"
+	}
+fi
 
 # Discover "Overfull \[hv]box" and "Reference ... undefined" messages from LaTeX.
 sed -n '/\.tex/{s/^.*\/\([-a-z0-9]\+\.tex\).*$/\1/;h};
diff --git a/tools/check-source.sh b/tools/check-source.sh
index ffd7c94d47..900bf33295 100755
--- a/tools/check-source.sh
+++ b/tools/check-source.sh
@@ -21,6 +21,14 @@ function fail() {
     grep .
 }
 
+# If we detect GNU sed (on macOS installed with brew) then we will use it.
+# Otherwise the script can fail on macOS which ships with BSD sed.
+if command -v gsed >/dev/null 2>&1; then
+	GSED=$(command -v gsed)
+	sed() {
+		${GSED} "$@"
+	}
+fi
 
 # We require GNU tools.
 sed --version | grep -Fqe "GNU sed" || { echo "sed is not GNU sed"; exit 1; }