From 40c2d01da2ebfccf060a487f946bc79df0d33011 Mon Sep 17 00:00:00 2001
From: Denys Vlasenko <vda.linux@googlemail.com>
Date: Wed, 6 Aug 2025 14:02:05 +0200
Subject: [PATCH] libbb: make read_cmdline() replace chars 1..31 with '?', not
 space

Space was too inconspicuous on output

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
 libbb/procps.c |  2 +-
 procps/top.c   | 16 ++++++++++------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/libbb/procps.c b/libbb/procps.c
index fc31c075d..94bbd9eb5 100644
--- a/libbb/procps.c
+++ b/libbb/procps.c
@@ -578,7 +578,7 @@ int FAST_FUNC read_cmdline(char *buf, int col, unsigned pid, const char *comm)
 		 */
 		while (sz >= 0) {
 			if ((unsigned char)(buf[sz]) < ' ')
-				buf[sz] = ' ';
+				buf[sz] = (buf[sz] ? /*ctrl*/'?' : /*NUL*/' ');
 			sz--;
 		}
 
diff --git a/procps/top.c b/procps/top.c
index 96b3e2d4e..7902e82f0 100644
--- a/procps/top.c
+++ b/procps/top.c
@@ -166,7 +166,7 @@ struct globals {
 	top_status_t *top;
 	int ntop;
 	smallint inverted;
-	smallint not_first_line;
+	smallint first_line_printed;
 #if ENABLE_FEATURE_TOPMEM
 	smallint sort_field;
 #endif
@@ -420,8 +420,8 @@ static void print_line_buf(void)
 
 	G.lines_remaining--;
 	fmt = OPT_BATCH_MODE ? "\n""%.*s" : "\n""%.*s"CLREOL;
-	if (!G.not_first_line) {
-		G.not_first_line = 1;
+	if (!G.first_line_printed) {
+		G.first_line_printed = 1;
 		/* Go to top */
 		fmt = OPT_BATCH_MODE ? "%.*s" : HOME"%.*s"CLREOL;
 	}
@@ -432,9 +432,9 @@ static void print_line_bold(void)
 {
 	G.lines_remaining--;
 //we never print first line in bold
-//	if (!G.not_first_line) {
+//	if (!G.first_line_printed) {
 //		printf(OPT_BATCH_MODE ? "%.*s" : HOME"%.*s"CLREOL, G.scr_width - 1, G.line_buf);
-//		G.not_first_line = 1;
+//		G.first_line_printed = 1;
 //	} else {
 		printf(OPT_BATCH_MODE ? "\n""%.*s" : "\n"REVERSE"%.*s"NORMAL CLREOL, G.scr_width - 1, G.line_buf);
 //	}
@@ -443,7 +443,8 @@ static void print_line_bold(void)
 static void print_end(void)
 {
 	fputs_stdout(OPT_BATCH_MODE ? "\n" : CLREOS"\r");
-	G.not_first_line = 0; /* next print will be "first line" (will clear the screen) */
+	/* next print will be "first line" (will clear the screen) */
+	G.first_line_printed = 0;
 }
 
 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS && ENABLE_FEATURE_TOP_DECIMALS
@@ -1204,6 +1205,9 @@ int top_main(int argc UNUSED_PARAM, char **argv)
 
 	INIT_G();
 
+//worth it?
+//	setvbuf(stdout, /*buf*/ NULL, _IOFBF, /*size*/ 0);
+
 	interval = 5; /* default update interval is 5 seconds */
 	iterations = 0; /* infinite */
 #if ENABLE_FEATURE_TOP_SMP_CPU