Help with inserting a line

Hello,

I am new to this forum. I have a question in Unix shell scripting. Here is my requirement

I have 1000 files and I need to insert a header with one line at the top of
each of the 1000 files. Please let me know if you have any solution for this

Thanks in advance.

Raj

perl -i -0pe '$_="header\n" . $_' *

suppose all files in one directory (not tested but should work) :
HEADER="--- This is the header ---
"
for F in *
do
echo "$HEADER$(cat $F)" > $F
done

$ ruby -i.bak -pe '$_="text\n#{$_}" if $.==1' file
$ sed -i '1 i text' file

######## This match to you requirement perfectly########
HEADER="This is the header line"

    for F in \*
    do
       echo "$HEADER\\n$\(cat $F\)" > $F
    done