From 8b56edcda001038a7ed3e63dc44c545fc0b02227 Mon Sep 17 00:00:00 2001
From: P. J. McDermott <pj@pehjota.net>
Date: Thu, 05 Oct 2023 09:28:17 -0400
Subject: build: Optionally install "@" symbolic link

---
diff --git a/Makefile.am b/Makefile.am
index c08fb30..c6d8e2b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -77,6 +77,21 @@ really-clean: distclean
 		$(srcdir)/build-aux/ $(srcdir)/INSTALL $(srcdir)/Makefile.in \
 		$(srcdir)/ChangeLog
 
+if ENABLE_SYMLINK
+install-exec-hook:
+	@set -e; \
+		dst="$$(printf 'atsign' | \
+			sed 's/$(EXEEXT)$$//;$(transform);s/$$/$(EXEEXT)/')"; \
+		src='$(DESTDIR)$(bindir)/@$(EXEEXT)'; \
+		echo " $(LN_S) '$${dst}' '$${src}'"; \
+		$(LN_S) "$${dst}" "$${src}"
+uninstall-hook:
+	@set -e; \
+		src='$(DESTDIR)$(bindir)/@$(EXEEXT)'; \
+		echo " rm -f '$${src}'"; \
+		rm -f "$${src}"
+endif
+
 dist-hook:
 if IN_GIT
 	printf 'Generated file.  Do not edit.\n\n' 1>'$(distdir)/ChangeLog~'
diff --git a/configure.ac b/configure.ac
index 40a3205..6578718 100644
--- a/configure.ac
+++ b/configure.ac
@@ -56,6 +56,19 @@ if ${funcs_missing}; then
 	AC_MSG_ERROR([required functions are missing])
 fi
 
+AC_PROG_LN_S()
+AC_ARG_ENABLE([symlink],
+	[AS_HELP_STRING([--disable-symlink],
+		[install \`@' symbolic link])],
+	dnl This `dnl' is needed to workaround Vim syntax highlighting.
+	[case "${enableval}" in yes|no) symlink=${enableval};;
+		*) AC_MSG_ERROR(
+			[bad value ${enableval} for symlink option]);;
+	esac],
+	[symlink=yes]
+)
+AM_CONDITIONAL([ENABLE_SYMLINK], [test x"${symlink}" = x'yes'])
+
 AC_ARG_ENABLE([tests],
 	[AS_HELP_STRING([--enable-tests],
 		[include test suite support in executable])],
--
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