(UTILS_FUNC_MKSTEMP): New file and macro.

Prompted by a report from Bob Proulx.

diff --git a/m4/mkstemp.m4 b/m4/mkstemp.m4
new file mode 100644 (file)
index 0000000..21bcc38
--- /dev/null
+++ b/m4/mkstemp.m4
@@ -0,0 +1,51 @@
+#serial 1
+
+# On some systems (e.g., HPUX-10.20), mkstemp has the silly limit that it
+# can create no more than 26 files from a given template.  Other systems
+# lack mkstemp altogether.  On either type of system, arrange to use the
+# replacement function.
+AC_DEFUN([UTILS_FUNC_MKSTEMP],
+[dnl
+  AC_REPLACE_FUNCS(mkstemp)
+  if test $ac_cv_func_mkstemp = no; then
+    utils_cv_func_mkstemp_limitations=yes
+  else
+    AC_CACHE_CHECK([for mkstemp limitations],
+      utils_cv_func_mkstemp_limitations,
+      [
+       utils_tmpdir_mkstemp=mkst-$$$$
+       # Arrange for deletion-upon-exception of this temporary directory.
+       ac_clean_files="$ac_clean_files $utils_tmpdir_mkstemp"
+       mkdir $utils_tmpdir_mkstemp
+
+       AC_TRY_RUN([
+#         include <stdlib.h>
+         int main ()
+         {
+           int i;
+           for (i = 0; i < 30; i++)
+             {
+               char template[] = "$utils_tmpdir_mkstemp/aXXXXXX";
+               if (mkstemp (template) == -1)
+                 exit (1);
+             }
+           exit (0);
+         }
+         ],
+       utils_cv_func_mkstemp_limitations=no,
+       utils_cv_func_mkstemp_limitations=yes,
+       utils_cv_func_mkstemp_limitations=yes
+       )
+
+       rm -rf $utils_tmpdir_mkstemp
+      ]
+    )
+  fi
+
+  if test $utils_cv_func_mkstemp_limitations = yes; then
+    AC_LIBOBJ(mkstemp)
+    AC_LIBOBJ(tempname)
+    AC_DEFINE(mkstemp, rpl_mkstemp,
+      [Define to rpl_mkstemp if the replacement function should be used.])
+  fi
+])