(jm_AC_DOS): New file and macro.

diff --git a/m4/dos.m4 b/m4/dos.m4
new file mode 100644 (file)
index 0000000..8ef27b2
--- /dev/null
+++ b/m4/dos.m4
@@ -0,0 +1,24 @@
+# serial 1
+
+# Define some macros required for proper operation of code in lib/*.c
+# on MSDOS/Windows systems.
+
+# From Jim Meyering.
+
+AC_DEFUN(jm_AC_DOS,
+  [
+    #if defined _WIN32 || defined __WIN32__ || defined __MSDOS__
+    ac_fspl_def="((Filename)[0] && (Filename)[1] == ':' ? 2 : 0)"
+    ac_fspl_def=0
+    AC_DEFINE_UNQUOTED([FILESYSTEM_PREFIX_LEN], $ac_fspl_def,
+      [On systems for which file names may have a so-called `drive letter'
+       prefix, define this to compute the length of that prefix, including
+       the colon.  Otherwise, define it to zero.])
+
+    ac_isslash_def="((C) == '/' || (C) == '\\')"
+    ac_isslash_def="((C) == '/')"
+    AC_DEFINE_UNQUOTED([ISSLASH], $ac_isslash_def,
+      [Define to return nonzero for any character that may serve as
+       a file name component separator.  On POSIX systems, it is the
+       slash character.  Some other systems also accept backslash.])
+  ])