Import getline helper from cdecl99.

[dxcommon.git] / m4 / getline.m4

diff --git a/m4/getline.m4 b/m4/getline.m4
new file mode 100644 (file)
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--- /dev/null
+++ b/m4/getline.m4
@@ -0,0 +1,31 @@
+# Copyright © 2024 Nick Bowler
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+# DX_CHECK_GETLINE
+#
+# Check whether or not the getline function is available.  If it is, the macro
+# HAVE_GETLINE is defined to 1 and the cache variable dx_cv_have_getline is set
+# to "yes".  Otherwise, dx_cv_have_getline is set to "no".
+AC_DEFUN([DX_CHECK_GETLINE],
+[AC_CACHE_CHECK([for getline], [dx_cv_have_getline],
+  [AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <stdio.h>
+], [ssize_t (*x)() = getline;
+char *p = 0;
+size_t n = 0;
+return getline(&p, &n, stdin);
+])], [dx_cv_have_getline=yes], [dx_cv_have_getline=no])])
+AS_CASE([$dx_cv_have_getline], [yes],
+  [AC_DEFINE([HAVE_GETLINE], [1],
+    [Define to 1 if the getline function is available.])])])