[PATCH 3/5] cmd: Convert echo to use cmd_result

[Sean Anderson]

This adds some complexity, since we need to know how big the arguments are
ahead of time instead of finding out when we print them.

Signed-off-by: Sean Anderson <seanga2 at gmail.com>
---

 cmd/echo.c | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/cmd/echo.c b/cmd/echo.c
index fda844ee9d..8f20e635ce 100644
--- a/cmd/echo.c
+++ b/cmd/echo.c
@@ -6,11 +6,16 @@
 
 #include <common.h>
 #include <command.h>
+#include <malloc.h>
+
+DECLARE_GLOBAL_DATA_PTR;
 
 static int do_echo(struct cmd_tbl *cmdtp, int flag, int argc,
 		   char *const argv[])
 {
-	int i = 1;
+	char *result;
+	int j, i = 1;
+	size_t result_size, arglens[CONFIG_SYS_MAXARGS];
 	bool space = false;
 	bool newline = true;
 
@@ -21,18 +26,32 @@ static int do_echo(struct cmd_tbl *cmdtp, int flag, int argc,
 		}
 	}
 
+	result_size = 1 + newline; /* \0 + \n */
+	result_size += argc - i - 1; /* spaces */
+	for (j = i; j < argc; ++j) {
+		arglens[j] = strlen(argv[j]);
+		result_size += arglens[j];
+	}
+
+	result = malloc(result_size);
+	if (!result)
+		return CMD_RET_FAILURE;
+	gd->cmd_result = result;
+
 	for (; i < argc; ++i) {
-		if (space) {
-			putc(' ');
-		}
-		puts(argv[i]);
+		if (space)
+			*result++ = ' ';
+
+		memcpy(result, argv[i], arglens[i]);
+		result += arglens[i];
 		space = true;
 	}
 
 	if (newline)
-		putc('\n');
+		*result++ = '\n';
+	*result = '\0';
 
-	return 0;
+	return CMD_RET_SUCCESS;
 }
 
 U_BOOT_CMD(
-- 
2.30.1