Allow console commands abbreviation

The EC console input handling code is being enhanced to accept
abbreviated command names.

If the abbreviation is unique, the appropriate command is used, if the
abbreviation is ambiguous, the command is handled as nonexistent. The
error message is being modified to mention that the command either
does not exist or is ambiguous.

This change also makes it impossible to have command names matching
the beginning of other command names. Two such cases are being fixed
(`ch' renamed to `chan' and `thermal' renamed to 'thermalconf').

BUG=none
TEST=manual
 . program the new EC image. Try entering at the console:
  > h
  Command 'h' either not found or ambiguous.
  Command returned error 1
  > he
  Known commands:
    adc            autofan        battery        ch             charger
  ...
  > help
  Known commands:
    adc            autofan        battery        ch             charger
  ...

Change-Id: Iaa3e91e1504e42daefb02d561e00c39003548197
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>

5 files changed, 34 insertions, 10 deletions

diff --git a/common/console.c b/common/console.c
index 50ca6da2d4..cdb5daf5e6 100644
--- a/common/console.c
+++ b/common/console.c
@@ -128,14 +128,18 @@ static int split_words(char *input, int max_argc, int *argc, char **argv)
  * no match found. */
 static const struct console_command *find_command(char *name)
 {
-	const struct console_command *cmd;
+	const struct console_command *cmd, *match = NULL;
+	int match_length = strlen(name);
 
 	for (cmd = __cmds; cmd < __cmds_end; cmd++) {
-		if (!strcasecmp(name, cmd->name))
-			return cmd;
+		if (!strncasecmp(name, cmd->name, match_length)) {
+			if (match)
+				return NULL;
+			match = cmd;
+		}
 	}
 
-	return NULL;
+	return match;
 }
 
 
@@ -159,7 +163,7 @@ static int handle_command(char *input)
 	if (cmd)
 		return cmd->handler(argc, argv);
 
-	ccprintf("Command '%s' not found.\n", argv[0]);
+	ccprintf("Command '%s' either not found or ambiguous.\n", argv[0]);
 	return EC_ERROR_UNKNOWN;
 }
 
@@ -293,7 +297,7 @@ static int command_ch(int argc, char **argv)
 	}
 
 	/* Otherwise, print help */
-	ccputs("Usage: ch [newmask]\n");
+	ccputs("Usage: chan [newmask]\n");
 	return EC_ERROR_INVAL;
 };
-DECLARE_CONSOLE_COMMAND(ch, command_ch);
+DECLARE_CONSOLE_COMMAND(chan, command_ch);
diff --git a/common/thermal.c b/common/thermal.c
index de98f47e00..154ddbbfb0 100644
--- a/common/thermal.c
+++ b/common/thermal.c
@@ -238,7 +238,7 @@ static int command_thermal_config(int argc, char **argv)
 	int sensor_type, threshold_id, value;
 
 	if (argc != 2 && argc != 4) {
-		ccputs("Usage: thermal <sensor_type> "
+		ccputs("Usage: thermalconf <sensor_type> "
 		       "[<threshold_id> <value>]\n");
 		return EC_ERROR_UNKNOWN;
 	}
@@ -273,7 +273,7 @@ static int command_thermal_config(int argc, char **argv)
 
 	return EC_SUCCESS;
 }
-DECLARE_CONSOLE_COMMAND(thermal, command_thermal_config);
+DECLARE_CONSOLE_COMMAND(thermalconf, command_thermal_config);
 
 
 static int command_fan_config(int argc, char **argv)
diff --git a/common/util.c b/common/util.c
index 47e9ba1226..b8afdf45c9 100644
--- a/common/util.c
+++ b/common/util.c
@@ -54,6 +54,22 @@ int strcasecmp(const char *s1, const char *s2)
 }
 
 
+int strncasecmp(const char *s1, const char *s2, int size)
+{
+	int diff;
+
+	if (!size)
+		return 0;
+
+	do {
+		diff = tolower(*s1) - tolower(*s2);
+		if (diff)
+			return diff;
+	} while (*(s1++) && *(s2++) && --size);
+	return 0;
+}
+
+
 int atoi(const char *nptr)
 {
 	int result = 0;
diff --git a/include/console.h b/include/console.h
index 78fc6d8df4..c2785cc545 100644
--- a/include/console.h
+++ b/include/console.h
@@ -76,7 +76,10 @@ void cflush(void);
 void console_has_input(void);
 
 
-/* Register a console command handler */
+/*
+ * Register a console command handler. Note that `name' must never be a
+ * beginning of another existing command name.
+ */
 #define DECLARE_CONSOLE_COMMAND(name, routine)			\
 	static const char __con_cmd_label_##name[] = #name;	\
 	const struct console_command __con_cmd_##name		\
diff --git a/include/util.h b/include/util.h
index 3fb0657061..6bbb8dd7df 100644
--- a/include/util.h
+++ b/include/util.h
@@ -66,6 +66,7 @@ void *memcpy(void *dest, const void *src, int len);
 void *memset(void *dest, int c, int len);
 void *memmove(void *dest, const void *src, int len);
 int strcasecmp(const char *s1, const char *s2);
+int strncasecmp(const char *s1, const char *s2, int size);
 int strlen(const char *s);
 int strtoi(const char *nptr, char **endptr, int base);