From 36e08dc49e2d18d2a42143d01a3ad333fe02065a Mon Sep 17 00:00:00 2001
From: liljencrantz <liljencrantz@gmail.com>
Date: Mon, 15 Oct 2007 21:39:36 +1000
Subject: [PATCH] Make the maximum execve size test use sysconf. Create a
 fallback if sysconf is unavailable.

darcs-hash:20071015113936-75c98-078e9f8727e91d41fabc80827bf97c8e04dd97ba.gz
---
 configure.ac |  2 +-
 exec.c       | 31 ++++++++++++++++++++-----------
 fallback.c   | 17 +++++++++++++++++
 fallback.h   |  7 +++++++
 4 files changed, 45 insertions(+), 12 deletions(-)

diff --git a/configure.ac b/configure.ac
index 786e9ef6e..bce63168b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -732,7 +732,7 @@ fi
 AC_CHECK_FUNCS( wcsdup wcsndup wcslen wcscasecmp wcsncasecmp fwprintf )
 AC_CHECK_FUNCS( futimes wcwidth wcswidth wcstok fputwc fgetwc )
 AC_CHECK_FUNCS( wcstol wcslcat wcslcpy lrand48_r killpg gettext )
-AC_CHECK_FUNCS( dcgettext backtrace backtrace_symbols)
+AC_CHECK_FUNCS( dcgettext backtrace backtrace_symbols sysconf )
 
 #
 # The Makefile also needs to know if we have gettext, so it knows if
diff --git a/exec.c b/exec.c
index 5fa8b6152..a0ce5ae1f 100644
--- a/exec.c
+++ b/exec.c
@@ -507,6 +507,8 @@ static void launch_process( process_t *p )
 			string_buffer_t sz1;
 			string_buffer_t sz2;
 			
+			long arg_max = -1;
+						
 			sb_init( &sz1 );
 			sb_init( &sz2 );
 						
@@ -521,19 +523,26 @@ static void launch_process( process_t *p )
 			}
 			
 			sb_format_size( &sz1, sz );
+
+			arg_max = sysconf( _SC_ARG_MAX );
 			
-#ifdef ARG_MAX
-			sb_format_size( &sz2, ARG_MAX );
+			if( arg_max > 0 )
+			{
+				
+				sb_format_size( &sz2, ARG_MAX );
+				
+				debug( 0,
+				       L"The total size of the argument and environment lists (%ls) exceeds the system limit of %ls.",
+				       (wchar_t *)sz1.buff,
+				       (wchar_t *)sz2.buff);
+			}
+			else
+			{
+				debug( 0,
+				       L"The total size of the argument and environment lists (%ls) exceeds the system limit.",
+				       (wchar_t *)sz1.buff);
+			}
 			
-			debug( 0,
-			       L"The total size of the argument and environment lists (%ls) exceeds the system limit of %ls.",
-			       (wchar_t *)sz1.buff,
-			       (wchar_t *)sz2.buff);
-#else
-			debug( 0,
-			       L"The total size of the argument and environment lists (%ls) exceeds the system limit.",
-			       (wchar_t *)sz1.buff);
-#endif
 			debug( 0, 
 			       L"Please try running the command again with fewer arguments.");
 			sb_destroy( &sz1 );
diff --git a/fallback.c b/fallback.c
index d686f58d8..af719cf51 100644
--- a/fallback.c
+++ b/fallback.c
@@ -1168,3 +1168,20 @@ char ** backtrace_symbols (void *const *buffer, int size)
 	return 0;
 }
 #endif
+
+#ifndef HAVE_SYSCONF
+
+long sysconf(int name)
+{
+	if( name == _SC_ARG_MAX )
+	{
+#ifdef ARG_MAX
+		return ARG_MAX;
+#endif
+	}
+
+	return -1;
+	
+}
+
+#endif
diff --git a/fallback.h b/fallback.h
index e6f8e3412..8f6289779 100644
--- a/fallback.h
+++ b/fallback.h
@@ -435,4 +435,11 @@ int getopt_long(int argc,
 
 #endif
 
+#ifndef HAVE_SYSCONF
+
+#define _SC_ARG_MAX 1
+long sysconf(int name);
+
+#endif
+
 #endif