check whether command returned any output?

[watergrinder]

 write header to file   
 connect sqlplus spool to sqltemp
 cat $sqltemp |  awk '{print $1, $2, $3}' | while read x y z
 do
 if something then 
    write output to file
 fi
 done

Here I would like to print header before output in a file. It should be written only if there is sqlplus output. it can't be put in loop because it repeats. Is there a way to know if cat found data in sqltemp file?

 

[PHV]

Something like this (in ksh)?
connect sqlplus spool to sqltemp
if [ $(awk 'NF{++nr}END{print nr}' $sqltemp) -gt 0 ]
then
write header
while read x y z remainder
do
if something then
write output
fi
done <$sqltemp
fi >/path/to/file

Hope This Help, PH.
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