Fix ss Netid column and Local/Peer_Address

When using ss -Hutn4 or -utn3, Netid and State columns are sometime merged, it can be confusing when trying to pipe into awk or column.
Details (before and after output) are available on this github issue: https://
github.com/shemminger/iproute2/issues/20

Signed-off-by YoyPa <[email protected]>

---
 misc/ss.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

misc/ss.c +2 -2

index c8970438..5e46cc0e 100644
@@ -144,9 +144,9 @@ static struct column columns[] = {
        { ALIGN_LEFT,   "State",                " ",    0, 0, 0 },
        { ALIGN_LEFT,   "Recv-Q",               " ",    0, 0, 0 },
        { ALIGN_LEFT,   "Send-Q",               " ",    0, 0, 0 },
-       { ALIGN_RIGHT,  "Local Address:",       " ",    0, 0, 0 },
+       { ALIGN_RIGHT,  "Local_Address:",       " ",    0, 0, 0 },
        { ALIGN_LEFT,   "Port",                 "",     0, 0, 0 },
-       { ALIGN_RIGHT,  "Peer Address:",        " ",    0, 0, 0 },
+       { ALIGN_RIGHT,  "Peer_Address:",        " ",    0, 0, 0 },
        { ALIGN_LEFT,   "Port",                 "",     0, 0, 0 },
        { ALIGN_LEFT,   "",                     "",     0, 0, 0 },
 };

When using ss -Hutn4 or -utn3, Netid and State columns are sometime merged, it can be confusing when trying to pipe into awk or column.

The actual issue seems to be that in some cases the left delimiter for the State column is not printed

On Mon, 29 Oct 2018 19:20:36 +0100

Quoted 2 lines · Stefano Brivio

The actual issue seems to be that in some cases the left delimiter for the State column is not printed

Much worse, we always print the left delimiter of the last buffered column, which is usually empty. My bad.

The issue is not so visible in general as we almost always have spaces to distribute around, but not if you start going below 70/75 columns. Can you try this?

misc/ss.c +0 -0

index f99b6874c228..90986b1dc15f 100644

misc/ss.c static void render(void) · line 1265

Quoted 4 lines

misc/ss.c +1 -1

-                       printed = printf("%s", current_field->ldelim);
+                       printed = printf("%s", f->ldelim);
                else
                        printed = 0;  

I can't reproduce the issue with this modification. :).

Hi Yohann,

On Fri, 26 Oct 2018 22:53:32 +0200

Quoted 2 lines · Yoann P.

When using ss -Hutn4 or -utn3, Netid and State columns are sometime merged, it can be confusing when trying to pipe into awk or column.

Thanks for fixing this. A few comments though:

Quoted 9 lines

misc/ss.c +1 -1

@@ -144,9 +144,9 @@ static struct column columns[] = {
 
        { ALIGN_LEFT,   "State",                " ",    0, 0, 0 },
        { ALIGN_LEFT,   "Recv-Q",               " ",    0, 0, 0 },
        { ALIGN_LEFT,   "Send-Q",               " ",    0, 0, 0 },
 
-       { ALIGN_RIGHT,  "Local Address:",       " ",    0, 0, 0 },
+       { ALIGN_RIGHT,  "Local_Address:",       " ",    0, 0, 0 },
 

misc/ss.c static struct column columns[] = { · line 149

Quoted 4 lines

misc/ss.c +1 -1

        { ALIGN_LEFT,   "Port",                 "",     0, 0, 0 },
 
-       { ALIGN_RIGHT,  "Peer Address:",        " ",    0, 0, 0 },
+       { ALIGN_RIGHT,  "Peer_Address:",        " ",    0, 0, 0 },

This is needed only if you pipe the output to column(1), I don't think it's a bug, because printing the header when you pass the output to column(1) makes little sense -- one should use -H then.

By the way, why do you use column(1), when ss already prints output in columns? Any other issue you are working around?

Quoted 7 lines

        { ALIGN_LEFT,   "Port",                 "",     0, 0, 0 },
        { ALIGN_LEFT,   "",                     "",     0, 0, 0 },

};

misc/ss.c static void sock_state_print(struct sockstat *s) · line 1337

Quoted 9 lines

misc/ss.c +1 -1

@@ -1334,7 +1334,7 @@ static void sock_state_print(struct sockstat *s)
 
                out("`- %s", sctp_sstate_name[s->state]);
 
        } else {
 
                field_set(COL_NETID);
 
-               out("%s", sock_name);
+               out("%-6s", sock_name);

I could reproduce this issue with a 70-columns terminal and the options you gave.

Anyway, I don't think this is the right way to fix it: this will waste one to two columns in case we have three letters for the Netid specifier, and won't work the day we get six-letters names. In general, it looks like a bad idea to reintroduce hardcoded width counts.

The actual issue seems to be that in some cases the left delimiter for the State column is not printed, and I think you should fix that instead. I'll look into this within a couple of days and give you some more specific hints in case you still need them by then.

Quoted 2 lines

By the way, why do you use column(1), when ss already prints output in columns? Any other issue you are working around?

column can hide columns with "-H -" and is a bit faster than awk to output a single column according to time, it's the only reason I mentioned it.

On Mon, 29 Oct 2018 21:06:35 +0100

Quoted 5 lines · Yoann P.

Quoted 2 lines

By the way, why do you use column(1), when ss already prints output in columns? Any other issue you are working around?

column can hide columns with "-H -" and is a bit faster than awk to output a single column according to time, it's the only reason I mentioned it.

Okay, but why do you need to hide some columns in the first place? I'm wondering if your use case would justify adding options to print selected columns only, in a generic way (right now, you can only disable some).

Another possibility would be to rename "Local Address:" to "Local:" and "Peer Address:" to "Peer:" -- in some cases (UNIX sockets) it's already not so much of an address, more of a path, and "Address" doesn't really add value when the field contains an address.

I don't like too much "Local_Address:" and "Peer_Address:" as the output is supposed to be human-readable by default, and that underscore just doesn't fit.