using external .sql files from shell script ?

Hello all

#> I hope you can help me. I am a novice to postgreSQL.
#> I'm tying to write a little shellscript/SQL application on unix system.
#> I use a simple shell script that calls some external SQL insructions
file.

#> so I have 2 questions about it
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1) Is there any oracle-SPOOL similar command under psql ?
#> actually I use psql -f foobar.sql

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2) How to use shell scripts variables as parameter to the external .sql
file ?

#> for example currently I must do :

#!/bin/sh
.....
.....
read toto
.....
psql -f $commande.sql $basename -o $commande.log
.....
exit

#> all my .sql files look like :
.....
\set foo '\''`echo $toto`'\''
\set tabl '\''`echo $table`'\''
.....
begin
.....
insert into :tabl values(....,....,....,:foo,....);
.....
end

#> So is this possible to use toto named variable from shell script
without creating foo named variable in .sql script ?
#> Is there a better method to do so ?

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regards