If Netid or State columns are missing, we must not subtract one for each of these two columns from the remaining screen width, while distributing available space to columns. This one character corresponding to one delimiting space has to be subtracted only if the columns are actually printed.
Further, in the existing implementation, if the screen width is an odd number, one additional character is added to the width of one of the two columns. But if both are not printed, this filling character needs to be added somewhere else, in order to have the right spacing allowing us to fill lines completely. Address and port fields are printed in pairs (local and remote), so we can't distribute the space to any of them, because it would be doubled. Instead, print this additional space to the right of the Send-Q column, to keep code changes to a minimum. This is particularly visible with 'ss -f netlink -Z'. Before this patch, with an 80 column terminal, we have: $ ss -f netlink -Z|head -n3 Recv-Q Send-Q Local Address:Port Peer Address:Port 0 0 rtnl:evolution-calen/2049 * pr oc_ctx=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 0 0 rtnl:clock-applet/1944 * pr oc_ctx=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 and with an 81 column terminal: $ ss -f netlink -Z|head -n3 Recv-Q Send-Q Local Address:Port Peer Address:Port 0 0 rtnl:evolution-calen/2049 * pro c_ctx=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 0 0 rtnl:clock-applet/1944 * pro c_ctx=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 After this patch, in both cases, the output is: $ ss -f netlink -Z|head -n3 Recv-Q Send-Q Local Address:Port Peer Address:Port 0 0 rtnl:evolution-calen/2049 * proc_ctx=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 0 0 rtnl:clock-applet/1944 * proc_ctx=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 Signed-off-by: Stefano Brivio <sbri...@redhat.com> --- Note: the extra line printed after the header is still present, we will need some slightly more invasive changes to fix this. misc/ss.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/misc/ss.c b/misc/ss.c index fb80d84122fc..fd7308042c71 100644 --- a/misc/ss.c +++ b/misc/ss.c @@ -107,6 +107,7 @@ int netid_width; int state_width; int addr_width; int serv_width; +char *odd_width_pad=""; static const char *TCP_PROTO = "tcp"; static const char *SCTP_PROTO = "sctp"; @@ -838,7 +839,7 @@ static void sock_state_print(struct sockstat *s) printf("%-*s ", state_width, sstate_name[s->state]); } - printf("%-6d %-6d ", s->rq, s->wq); + printf("%-6d %-6d %s", s->rq, s->wq, odd_width_pad); } static void sock_details_print(struct sockstat *s) @@ -4364,8 +4365,8 @@ int main(int argc, char *argv[]) } addrp_width = screen_width; - addrp_width -= netid_width+1; - addrp_width -= state_width+1; + addrp_width -= netid_width + 1 * !!netid_width; + addrp_width -= state_width + 1 * !!state_width; addrp_width -= 14; if (addrp_width&1) { @@ -4373,6 +4374,8 @@ int main(int argc, char *argv[]) netid_width++; else if (state_width) state_width++; + else + odd_width_pad=" "; } addrp_width /= 2; @@ -4390,7 +4393,7 @@ int main(int argc, char *argv[]) printf("%-*s ", netid_width, "Netid"); if (state_width) printf("%-*s ", state_width, "State"); - printf("%-6s %-6s ", "Recv-Q", "Send-Q"); + printf("%-6s %-6s %s", "Recv-Q", "Send-Q", odd_width_pad); } /* Make enough space for the local/remote port field */ -- 2.9.4