Propagate Error Status to the Shell on fw_printenv Errors

Changed implementation such that fw_printenv returns failure status
when one or more specified variables do not exist or when incorrect
command syntax is used.

This aids scripting fw_printenv such that the script can key of the
return status rather than relying on standard error "scraping".

Signed-off-by: Grant Erickson <gerickson@nuovations.com>
Signed-off-by: Wolfgang Denk <wd@denx.de>

3 files changed, 29 insertions, 21 deletions

diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
index e083a5b..b8bca91 100644
--- a/tools/env/fw_env.c
+++ b/tools/env/fw_env.c
@@ -1,5 +1,5 @@
 /*
- * (C) Copyright 2000-2003
+ * (C) Copyright 2000-2008
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
  * See file CREDITS for list of people who contributed to this
@@ -209,13 +209,14 @@ char *fw_getenv (char *name)
  * Print the current definition of one, or more, or all
  * environment variables
  */
-void fw_printenv (int argc, char *argv[])
+int fw_printenv (int argc, char *argv[])
 {
 	char *env, *nxt;
 	int i, n_flag;
+	int rc = 0;
 
 	if (env_init ())
-		return;
+		return (-1);
 
 	if (argc == 1) {		/* Print all env variables  */
 		for (env = environment.data; *env; env = nxt + 1) {
@@ -223,13 +224,13 @@ void fw_printenv (int argc, char *argv[])
 				if (nxt >= &environment.data[ENV_SIZE]) {
 					fprintf (stderr, "## Error: "
 						"environment not terminated\n");
-					return;
+					return (-1);
 				}
 			}
 
 			printf ("%s\n", env);
 		}
-		return;
+		return (0);
 	}
 
 	if (strcmp (argv[1], "-n") == 0) {
@@ -239,7 +240,7 @@ void fw_printenv (int argc, char *argv[])
 		if (argc != 2) {
 			fprintf (stderr, "## Error: "
 				"`-n' option requires exactly one argument\n");
-			return;
+			return (-1);
 		}
 	} else {
 		n_flag = 0;
@@ -255,7 +256,7 @@ void fw_printenv (int argc, char *argv[])
 				if (nxt >= &environment.data[ENV_SIZE]) {
 					fprintf (stderr, "## Error: "
 						"environment not terminated\n");
-					return;
+					return (-1);
 				}
 			}
 			val = envmatch (name, env);
@@ -268,9 +269,13 @@ void fw_printenv (int argc, char *argv[])
 				break;
 			}
 		}
-		if (!val)
+		if (!val) {
 			fprintf (stderr, "## Error: \"%s\" not defined\n", name);
+			rc = -1;
+		}
 	}
+
+	return (rc);
 }
 
 /*
diff --git a/tools/env/fw_env.h b/tools/env/fw_env.h
index 58607de..248f58c 100644
--- a/tools/env/fw_env.h
+++ b/tools/env/fw_env.h
@@ -1,5 +1,5 @@
 /*
- * (C) Copyright 2002
+ * (C) Copyright 2002-2008
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
  * See file CREDITS for list of people who contributed to this
@@ -47,7 +47,7 @@
 	"ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off; " 	\
 	"bootm"
 
-extern void  fw_printenv(int argc, char *argv[]);
+extern int   fw_printenv(int argc, char *argv[]);
 extern char *fw_getenv  (char *name);
 extern int fw_setenv  (int argc, char *argv[]);
 
diff --git a/tools/env/fw_env_main.c b/tools/env/fw_env_main.c
index 696e30e..7f631c4 100644
--- a/tools/env/fw_env_main.c
+++ b/tools/env/fw_env_main.c
@@ -1,5 +1,5 @@
 /*
- * (C) Copyright 2000
+ * (C) Copyright 2000-2008
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
  * See file CREDITS for list of people who contributed to this
@@ -25,15 +25,16 @@
  * Command line user interface to firmware (=U-Boot) environment.
  *
  * Implements:
- *	fw_printenv [ name ... ]
- *		- prints the values of the environment variables
- *		  "name", or the whole environment if no names are
- *		  specified
+ *	fw_printenv [[ -n name ] | [ name ... ]]
+ *              - prints the value of a single environment variable
+ *                "name", the ``name=value'' pairs of one or more
+ *                environment variables "name", or the whole
+ *                environment if no names are specified.
  *	fw_setenv name [ value ... ]
  *		- If a name without any values is given, the variable
  *		  with this name is deleted from the environment;
  *		  otherwise, all "value" arguments are concatenated,
- *		  separated by sinlge blank characters, and the
+ *		  separated by single blank characters, and the
  *		  resulting string is assigned to the environment
  *		  variable "name"
  */
@@ -58,16 +59,18 @@ main(int argc, char *argv[])
 
 	if (strcmp(cmdname, CMD_PRINTENV) == 0) {
 
-			fw_printenv (argc, argv);
+		if (fw_printenv (argc, argv) != 0)
+			return (EXIT_FAILURE);
 
-			return (EXIT_SUCCESS);
+		return (EXIT_SUCCESS);
 
 	} else if (strcmp(cmdname, CMD_SETENV) == 0) {
 
-			if (fw_setenv (argc, argv) != 0)
-				return (EXIT_FAILURE);
+		if (fw_setenv (argc, argv) != 0)
+			return (EXIT_FAILURE);
+
+		return (EXIT_SUCCESS);
 
-			return (EXIT_SUCCESS);
 	}
 
 	fprintf (stderr,