Commented by: @pavel-zotov

If you create trivial script:
C:\FB\30SS>echo set heading off;select count(*) from rdb$database; > c:\temp\tmp4isql.tmp

... and run ISQL like this:
C:\FB\30SS>C:\FB\30SS\isql /:e30 -i c:\temp\tmp4isql.tmp

-- then outbut will contain two empty lines and result of count(*), but WITHOUT header and "========":

                1

PS.
Unfortunately, for some backward compatibility reasons one can not do almost the same but using PIPE (without creating script):

C:\FB\30SS>echo set heading off;select count(*) from rdb$database; | C:\FB\30SS\isql /:e30 -q
Database: /:e30, User: SYSDBA
SQL>
1

SQL>

Garbage lines with "SQL>" prompt appear always :(

Commented by: Ray Holme (rholme)

Nice Pavel. Thank you.

So to summarize and get SUPER quiet -
a) use "isql -q"
b) embed the following command before doing anything else
"set heading off;"

I assume one does not need to specify "-page 999999999" as ALL heading are gone
and even voluminous output will not get a page heading.

VERY NICE. Thanks again. Close this one and suggest that it go in the FB book.

Commented by: Ray Holme (rholme)

Just a note in passing, I do NOT get "SQL>" in my output streams.

I suspect that is because isql knows my input is not from a human typing, but from an input stream
I think that is a feature - at least it is in Linux and I like it a lot (don't change that :=]]] )

[rainbow]$ echo 'set heading off;select count(*) from rdb$database;' | isql $DB

       1