add get_arg_max(). Use sysconf() if ARG_MAX is not defined.

ChangeLog

@@ -13,6 +13,8 @@
  - (djm) Release 2.5.2p1
 - tim@mindrot.org 2001/03/19 18:33:47 [defines.h]
   change S_ISLNK macro to work for UnixWare 2.03
+- tim@mindrot.org 2001/03/19 20:45:11 [openbsd-compat/glob.c]
+  add get_arg_max(). Use sysconf() if ARG_MAX is not defined
 
 20010319
  - (djm) Seed PRNG at startup, rather than waiting for arc4random calls to 
@@ -4643,4 +4645,4 @@
  - Wrote replacements for strlcpy and mkdtemp
  - Released 1.0pre1
 
-$Id: ChangeLog,v 1.992 2001/03/20 02:31:44 tim Exp $
+$Id: ChangeLog,v 1.993 2001/03/20 04:46:50 tim Exp $

openbsd-compat/glob.c

@@ -37,6 +37,18 @@
 #include "includes.h"
 #include <ctype.h>
 
+long
+get_arg_max()
+{
+#ifdef ARG_MAX
+	return(ARG_MAX);
+#elif defined(HAVE_SYSCONF) && defined(_SC_ARG_MAX)
+	return(sysconf(_SC_ARG_MAX));
+#else
+	return(256); /* XXX: arbitrary */
+#endif
+}
+
 #if !defined(HAVE_GLOB) || !defined(GLOB_HAS_ALTDIRFUNC) || \
     !defined(GLOB_HAS_GL_MATCHC)
 
@@ -689,7 +701,7 @@ globextend(path, pglob, limitp)
 	pathv[pglob->gl_offs + pglob->gl_pathc] = NULL;
 
 	if ((pglob->gl_flags & GLOB_LIMIT) &&
-	    newsize + *limitp >= ARG_MAX) {
+	    newsize + *limitp >= (u_int) get_arg_max()) {
 		errno = 0;
 		return(GLOB_NOSPACE);
 	}