Sybase ASE find running process
There is no direct way of doing it in SybaseASE (as opposed to sql server - which exposes DMV data).

You can get close to see if your UPDATE INDEX STATISTICS is getting CPU, Physical IO and is not being blocked.

I use below query :

select l.spid
    ,p.status as status
    ,Db_name(l.dbid) as dbname
    ,p.hostname as hostname
    ,p.program_name as program_name
    ,substring(Object_name(l.id, l.dbid), 1, 30) as object
    ,p.blocked
    ,case 
        when type = 1
            then "Exclusive table lock"
        when type = 2
            then "Shared table lock"
        when type = 3
            then "Exclusive intent lock"
        when type = 4
            then "Shared intent lock"
        when type = 5
            then "Exclusive page lock"
        when type = 6
            then "Shared page lock"
        when type = 7
            then "Update page lock"
        when type = 8
            then "Exclusive row lock"
        when type = 9
            then "Shared row lock"
        when type = 10
            then "Update row lock"
        when type = 11
            then "Shared next key lock"
        when type = 256
            then "Lock is blocking another process"
        when type = 512
            then "Demand lock"
        end as "TYPE_OF_LOCK"
    ,l.page "Page"
    ,Substring(p.cmd, 1, 16) as executing_command
    ,p.physical_io as "PHYSICAL_I/O"
    ,p.cpu as cpu
from master..syslocks l
    ,master..sysprocesses p
where l.spid = p.spid