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

[Heinrich Schuchardt]

Am 1. März 2021 00:47:16 MEZ schrieb Sean Anderson <seanga2 at gmail.com>:
>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.

Why do you want to add complexity?

Where is the documentation update?

Best regards

Heinrich


>
>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(