diff mbox series

[net-next] ss: use compact output for undetected screen width

Message ID 20191226130709.GA29733@peto-laptopnovy
State Accepted
Delegated to: David Ahern
Headers show
Series [net-next] ss: use compact output for undetected screen width | expand

Commit Message

Peter Junos Dec. 26, 2019, 1:07 p.m. UTC
This change fixes calculation of width in case user pipes the output.

SS output output works correctly when stdout is a terminal. When one
pipes the output, it tries to use 80 or 160 columns. That adds a
line-break if user has terminal width of 100 chars and output is of
the similar width. No width is assumed here.

To reproduce the issue, call
ss | less
and see every other line empty if your screen is between 80 and 160
columns wide.

This second version of the patch fixes screen_width being set to arbitrary
value.

Signed-off-by: Peter Junos <petoju@gmail.com>
---
 misc/ss.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

Comments

David Ahern Jan. 2, 2020, 6:42 p.m. UTC | #1
On 12/26/19 6:07 AM, Peter Junos wrote:
> This change fixes calculation of width in case user pipes the output.
> 
> SS output output works correctly when stdout is a terminal. When one
> pipes the output, it tries to use 80 or 160 columns. That adds a
> line-break if user has terminal width of 100 chars and output is of
> the similar width. No width is assumed here.
> 
> To reproduce the issue, call
> ss | less
> and see every other line empty if your screen is between 80 and 160
> columns wide.
> 
> This second version of the patch fixes screen_width being set to arbitrary
> value.
> 
> Signed-off-by: Peter Junos <petoju@gmail.com>
> ---
>  misc/ss.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
> 

...

> @@ -1159,9 +1159,15 @@ static int render_screen_width(void)
>   */
>  static void render_calc_width(void)
>  {
> -	int screen_width = render_screen_width();
> +	int screen_width, first, len = 0, linecols = 0;
> +	bool compact_output = false;
>  	struct column *c, *eol = columns - 1;
> -	int first, len = 0, linecols = 0;

moved the new bool after struct column to maintain reverse xmas tree and
applied to iproute2-next. Thanks,
diff mbox series

Patch

diff --git a/misc/ss.c b/misc/ss.c
index 95f1d37a..d5bae16d 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -1135,10 +1135,10 @@  static void buf_free_all(void)
 	buffer.chunks = 0;
 }
 
-/* Get current screen width, default to 80 columns if TIOCGWINSZ fails */
+/* Get current screen width, returns -1 if TIOCGWINSZ fails */
 static int render_screen_width(void)
 {
-	int width = 80;
+	int width = -1;
 
 	if (isatty(STDOUT_FILENO)) {
 		struct winsize w;
@@ -1159,9 +1159,15 @@  static int render_screen_width(void)
  */
 static void render_calc_width(void)
 {
-	int screen_width = render_screen_width();
+	int screen_width, first, len = 0, linecols = 0;
+	bool compact_output = false;
 	struct column *c, *eol = columns - 1;
-	int first, len = 0, linecols = 0;
+
+	screen_width = render_screen_width();
+	if (screen_width == -1) {
+		screen_width = INT_MAX;
+		compact_output = true;
+	}
 
 	/* First pass: set width for each column to measured content length */
 	for (first = 1, c = columns; c - columns < COL_MAX; c++) {
@@ -1183,6 +1189,11 @@  static void render_calc_width(void)
 			first = 0;
 	}
 
+	if (compact_output) {
+		/* Compact output, skip extending columns. */
+		return;
+	}
+
 	/* Second pass: find out newlines and distribute available spacing */
 	for (c = columns; c - columns < COL_MAX; c++) {
 		int pad, spacing, rem, last;