1 files changed, 97 insertions, 0 deletions
diff --git a/m4/stpncpy.m4 b/m4/stpncpy.m4
new file mode 100644
index 0000000..ea1089b
--- /dev/null
+++ b/m4/stpncpy.m4
@@ -0,0 +1,97 @@
+# stpncpy.m4 serial 16
+dnl Copyright (C) 2002-2003, 2005-2007, 2009-2016 Free Software Foundation,
+dnl Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_STPNCPY],
+[
+  dnl Persuade glibc <string.h> to declare stpncpy().
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  dnl The stpncpy() declaration in lib/string.in.h uses 'restrict'.
+  AC_REQUIRE([AC_C_RESTRICT])
+
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+
+  dnl Both glibc and AIX (4.3.3, 5.1) have an stpncpy() function
+  dnl declared in <string.h>. Its side effects are the same as those
+  dnl of strncpy():
+  dnl      stpncpy (dest, src, n)
+  dnl overwrites dest[0..n-1], min(strlen(src),n) bytes coming from src,
+  dnl and the remaining bytes being NULs.  However, the return value is
+  dnl   in glibc:   dest + min(strlen(src),n)
+  dnl   in AIX:     dest + max(0,n-1)
+  dnl Only the glibc return value is useful in practice.
+
+  AC_CHECK_DECLS_ONCE([stpncpy])
+  AC_CHECK_FUNCS_ONCE([stpncpy])
+  if test $ac_cv_func_stpncpy = yes; then
+    AC_CACHE_CHECK([for working stpncpy], [gl_cv_func_stpncpy], [
+      AC_RUN_IFELSE(
+        [AC_LANG_SOURCE([[
+#include <stdlib.h>
+#include <string.h> /* for strcpy */
+/* The stpncpy prototype is missing in <string.h> on AIX 4.  */
+#if !HAVE_DECL_STPNCPY
+extern
+# ifdef __cplusplus
+"C"
+# endif
+char *stpncpy (char *dest, const char *src, size_t n);
+#endif
+int main ()
+{
+  int result = 0;
+  const char *src = "Hello";
+  char dest[10];
+  /* AIX 4.3.3 and AIX 5.1 stpncpy() returns dest+1 here.  */
+  {
+    strcpy (dest, "\377\377\377\377\377\377");
+    if (stpncpy (dest, src, 2) != dest + 2)
+      result |= 1;
+  }
+  /* AIX 4.3.3 and AIX 5.1 stpncpy() returns dest+4 here.  */
+  {
+    strcpy (dest, "\377\377\377\377\377\377");
+    if (stpncpy (dest, src, 5) != dest + 5)
+      result |= 2;
+  }
+  /* AIX 4.3.3 and AIX 5.1 stpncpy() returns dest+6 here.  */
+  {
+    strcpy (dest, "\377\377\377\377\377\377");
+    if (stpncpy (dest, src, 7) != dest + 5)
+      result |= 4;
+  }
+  return result;
+}
+]])],
+        [gl_cv_func_stpncpy=yes],
+        [gl_cv_func_stpncpy=no],
+        [AC_EGREP_CPP([Thanks for using GNU], [
+#include <features.h>
+#ifdef __GNU_LIBRARY__
+  Thanks for using GNU
+#endif
+], [gl_cv_func_stpncpy="guessing yes"], [gl_cv_func_stpncpy="guessing no"])
+        ])
+    ])
+    case "$gl_cv_func_stpncpy" in
+      *yes)
+        AC_DEFINE([HAVE_STPNCPY], [1],
+          [Define if you have the stpncpy() function and it works.])
+        ;;
+      *)
+        REPLACE_STPNCPY=1
+        ;;
+    esac
+  else
+    HAVE_STPNCPY=0
+  fi
+])
+
+# Prerequisites of lib/stpncpy.c.
+AC_DEFUN([gl_PREREQ_STPNCPY], [
+  :
+])