insert text in the first line of a file

[goude]

Hello

Can anyone tell me how I can insert a text in the first line of a file. I'm trying to do that with the following, but it writes the file at the end of it.

 #!/usr/bin/perl 
   use strict;

system ("touch /tmp/txtfile");
my ($fileappend, $fileread, $filein);
$filein = '/tmp/txtfile';

open $fileread, '>', $filein || die ("Can't open: $filein $!");
print $fileread "\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n";    # Creates 20 blank lines
close $fileread;

open ($fileappend, ">>$filein");	# Open for appending
print $fileappend "blabla";

Thank you

[tpl]

let's suppose you have a line "abcdefg" first in file N
and you want it to read "abctestdefg" inserting "test"
between "c" and "d"

sed 's1/cd/ctestd/' <N

where the "1" is the lline number on which to operate

[goude]

Thank you for replying tpl

But what if the line is blank, and want to write ctestd only.
I tried this
sed 's1//ctestd/' <N but didn't work.

[ghostdog74]

very simply , you could just use cat

# echo "text to insert" >> temp
# cat file >> temp
# mv temp file

[goude]

Simple but clever!
Thanks a lot for your help guys.

[secondmouse]

perl -i~ -0777pe's/^/New first line\n/' yourfile

Reference: Insert line in the first line - Dev Archives

[ghostdog74]

perl -i~ -0777pe's/^/New first line\n/' yourfile

Reference: Insert line in the first line - Dev Archives

cool, but for huge files, it will still be slower than using cat.