diff -ur esh-20110121/esh/src/esh.c esh-20110929/esh/src/esh.c
--- esh-20110121/esh/src/esh.c	2011-01-21 15:17:02.000000000 -0500
+++ esh-20110929/esh/src/esh.c	2011-09-29 11:41:37.000000000 -0400
@@ -99,9 +99,14 @@
 
         struct esh_command_line * cline = shell.parse_command_line(cmdline);
         free (cmdline);
-        if (list_empty(&cline->pipes))    /* User hit enter */
+        if (cline == NULL)                  /* Error in command line */
             continue;
 
+        if (list_empty(&cline->pipes)) {    /* User hit enter */
+            esh_command_line_free(cline);
+            continue;
+        }
+
         esh_command_line_print(cline);
         esh_command_line_free(cline);
     }
diff -ur esh-20110121/esh/src/esh-grammar.y esh-20110929/esh/src/esh-grammar.y
--- esh-20110121/esh/src/esh-grammar.y	2011-01-21 15:17:02.000000000 -0500
+++ esh-20110929/esh/src/esh-grammar.y	2011-09-29 11:41:37.000000000 -0400
@@ -6,6 +6,8 @@
  *
  * This is based on an assignment I did in 1993 as an undergraduate
  * student at Technische Universitaet Berlin.
+ *
+ * Known bugs: leaks memory when parse errors occur.
  */
 %{
 #include <stdio.h>
@@ -167,12 +169,14 @@
             obstack_ptr_grow(&$$.words, $2);
 		}
 |		command input {
+            obstack_free(&$2.words, NULL);
             /* Error: ambiguous redirect 'a <b <c' */
             if($1.iored_input)   { p_error(AMBINP); YYABORT; }
             $$ = $1; 
             $$.iored_input = $2.iored_input;
 		}
 |		command output {
+            obstack_free(&$2.words, NULL);
             /* Error: ambiguous redirect 'a >b >c' */
             if ($1.iored_output) { p_error(AMBOUT); YYABORT; }
             $$ = $1; 
diff -ur esh-20110121/esh/src/esh.h esh-20110929/esh/src/esh.h
--- esh-20110121/esh/src/esh.h	2011-01-21 15:17:02.000000000 -0500
+++ esh-20110929/esh/src/esh.h	2011-09-29 11:41:37.000000000 -0400
@@ -4,7 +4,7 @@
  * Developed by Godmar Back for CS 3214 Fall 2009
  * Virginia Tech.
  * 
- * $Id: esh.h,v 1.6 2011/01/21 20:11:26 cs3214 Exp $
+ * $Id: esh.h,v 1.7 2011/09/29 15:39:20 cs3214 Exp $
  */
 
 #include <stdbool.h>
@@ -63,8 +63,10 @@
     /* Initialize plugin and pass shell object */
     bool (* init)(struct esh_shell *);
 
-    /* A plugin may return false for each following functions 
-     * to indicate that processing should stop.
+    /* The return value of the following three functions indicates
+     * whether the plugin wants processing to stop.
+     * true - indicates processing should stop.
+     * false - indicates processing should continue.
      */
     /* The command line the user entered.
      * A plugin may change it. */
diff -ur esh-20110121/esh/src/eshoutput.py esh-20110929/esh/src/eshoutput.py
--- esh-20110121/esh/src/eshoutput.py	2011-01-21 15:17:02.000000000 -0500
+++ esh-20110929/esh/src/eshoutput.py	2011-09-29 11:41:37.000000000 -0400
@@ -36,6 +36,9 @@
 #
 # builtin commands
 #
+# Use printf-style formats. stop, kill, fg, and bg expect job ids.
+# If your shell requires a % before the jobid, use %%%s.
+#
 builtin_commands = {
     'jobs' : 'jobs',
     'stop' : 'stop %s',
@@ -43,6 +46,3 @@
     'fg'   : 'fg %s',
     'bg'   : 'bg %s'
 }
-
-# logfile = open("/dev/tty", "w")
-
diff -ur esh-20110121/esh/src/esh-sys-utils.c esh-20110929/esh/src/esh-sys-utils.c
--- esh-20110121/esh/src/esh-sys-utils.c	2011-01-21 15:17:02.000000000 -0500
+++ esh-20110929/esh/src/esh-sys-utils.c	2011-09-29 11:41:37.000000000 -0400
@@ -20,7 +20,7 @@
 
 #include "esh-sys-utils.h"
 
-static const char rcsid [] = "$Id: esh-sys-utils.c,v 1.4 2011/01/21 20:11:26 cs3214 Exp $";
+static const char rcsid [] = "$Id: esh-sys-utils.c,v 1.5 2011/09/29 15:39:20 cs3214 Exp $";
 
 /* Utility function for esh_sys_fatal_error and esh_sys_error */
 static void 
@@ -151,7 +151,7 @@
          * signal handler is entered. */
         .sa_mask = emptymask,
         /* restart system calls when possible */
-        .sa_flags = SA_RESTART
+        .sa_flags = SA_RESTART | SA_SIGINFO
     };
 
     if (sigaction(sig, &sa, NULL) != 0)
diff -ur esh-20110121/esh/src/esh-utils.c esh-20110929/esh/src/esh-utils.c
--- esh-20110121/esh/src/esh-utils.c	2011-01-21 15:17:02.000000000 -0500
+++ esh-20110929/esh/src/esh-utils.c	2011-09-29 11:41:37.000000000 -0400
@@ -13,7 +13,7 @@
 
 #include "esh.h"
 
-static const char rcsid [] = "$Id: esh-utils.c,v 1.5 2011/01/21 20:11:26 cs3214 Exp $";
+static const char rcsid [] = "$Id: esh-utils.c,v 1.6 2011/09/29 15:39:20 cs3214 Exp $";
 
 /* List of loaded plugins */
 struct list esh_plugin_list;
@@ -176,6 +176,10 @@
     while (*p) {
         free(*p++);
     }
+    if (cmd->iored_input)
+        free(cmd->iored_input);
+    if (cmd->iored_output)
+        free(cmd->iored_output);
     free(cmd->argv);
     free(cmd);
 }