Add the function 'confirm_yesno' for interactive

User's confirmation is asked in different commands. This commit adds a
function for such confirmation.

Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Pierre Aubert <p.aubert@staubli.com>

common/cmd_fuse.c

@@ -33,15 +33,8 @@ static int confirm_prog(void)
 					"what you are doing!\n"
 			"\nReally perform this fuse programming? <y/N>\n");
 
-	if (getc() == 'y') {
-		int c;
-
-		putc('y');
-		c = getc();
-		putc('\n');
-		if (c == '\r')
-			return 1;
-	}
+	if (confirm_yesno())
+		return 1;
 
 	puts("Fuse programming aborted\n");
 	return 0;

common/cmd_nand.c

@@ -605,22 +605,16 @@ static int do_nand(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		opts.spread = spread;
 
 		if (scrub) {
-			if (!scrub_yes)
-				puts(scrub_warn);
-
-			if (scrub_yes)
+			if (scrub_yes) {
 				opts.scrub = 1;
-			else if (getc() == 'y') {
-				puts("y");
-				if (getc() == '\r')
+			} else {
+				puts(scrub_warn);
+				if (confirm_yesno()) {
 					opts.scrub = 1;
-				else {
+				} else {
 					puts("scrub aborted\n");
 					return 1;
 				}
-			} else {
-				puts("scrub aborted\n");
-				return 1;
 			}
 		}
 		ret = nand_erase_opts(nand, &opts);

common/cmd_otp.c

@@ -158,21 +158,9 @@ int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 			lowup(half + count - 1), page + (half + count - 1) / 2,
 			half + count
 		);
-
-		i = 0;
-		while (1) {
-			if (tstc()) {
-				const char exp_ans[] = "YES\r";
-				char c;
-				putc(c = getc());
-				if (exp_ans[i++] != c) {
-					printf(" Aborting\n");
-					return 1;
-				} else if (!exp_ans[i]) {
-					puts("\n");
-					break;
-				}
-			}
+		if (!confirm_yesno()) {
+			printf(" Aborting\n");
+			return 1;
 		}
 	}
 

common/console.c

@@ -537,7 +537,33 @@ int ctrlc(void)
 	}
 	return 0;
 }
-
+/* Reads user's confirmation.
+   Returns 1 if user's input is "y", "Y", "yes" or "YES"
+*/
+int confirm_yesno(void)
+{
+	int i;
+	char str_input[5];
+
+	/* Flush input */
+	while (tstc())
+		getc();
+	i = 0;
+	while (i < sizeof(str_input)) {
+		str_input[i] = getc();
+		putc(str_input[i]);
+		if (str_input[i] == '\r')
+			break;
+		i++;
+	}
+	putc('\n');
+	if (strncmp(str_input, "y\r", 2) == 0 ||
+	    strncmp(str_input, "Y\r", 2) == 0 ||
+	    strncmp(str_input, "yes\r", 4) == 0 ||
+	    strncmp(str_input, "YES\r", 4) == 0)
+		return 1;
+	return 0;
+}
 /* pass 1 to disable ctrlc() checking, 0 to enable.
  * returns previous state
  */

include/common.h

@@ -836,7 +836,7 @@ int	ctrlc (void);
 int	had_ctrlc (void);	/* have we had a Control-C since last clear? */
 void	clear_ctrlc (void);	/* clear the Control-C condition */
 int	disable_ctrlc (int);	/* 1 to disable, 0 to enable Control-C detect */
-
+int confirm_yesno(void);        /*  1 if input is "y", "Y", "yes" or "YES" */
 /*
  * STDIO based functions (can always be used)
  */