how to add one line at the top of a file

[Hanry Zhou]

thanks,

[Patrick Wallek]

Where are you trying to accomplish this? Within vi? Or using ed, sed, awk....?

If it is just within vi, you can do a -O (that is hold down shift and hit the letter O) while you are at the top of the file.

[Hanry Zhou]

please using command line.

[Fragon]

Use a shell scritp to do this:
=======================
#more addtotop
echo $1 >$$.tmp
cat $2 >>$$.tmp
cat $$.tmp >$2
rm $$.tmp
=======================
On how to use:
#addtotop "The string you want to add to the first line." FILENAME

Good luck!

[Michael Tully]

You actually get it doing this:

cat myfile | sed '1 s/^/\controlvcontrolj/'

it will appear on the screen as this:

cat myfile | sed '1 s/^/\^J/'

HTH
Michael

[Hanry Zhou]

I did not make myself clear.

Here is what I want to achieve.

I have a few lines coming from a output:
line1
line2
line3
and I want to add these lines
on the top of a file, myfile.

[Michael Tully]

How about this:

e.g.

# cat /tmp/wrk1
line1
line2
line3
# cat /tmp/wrk2
file1
file2
file3


# head -n 3 /tmp/wrk1 >/tmp/wrk3 ; cat /tmp/wrk2 >>/tmp/wrk3
# cat /tmp/wrk3
line1
line2
line3
file1
file2
file3

[MANOJ SRIVASTAVA]

Hi Roger


If u get line1
line2
line3 ina file say test then you can jsut

do

cat test >file
and then
cat myfile >> file


Manoj Srivastava

[Dietmar Konermann]

The is no efficient way to grow a file by inserting contents. You can only overwrite or append something... and you can truncate the file from the end.

So all solutions include unfortunately a complete and inefficient copy operation. See suggestions above and pick the one you like.

[Jean-Luc Oudart · Accepted solution]

take 1st 3 lines of file1 and insert them on top of file 2 :
( head -n3 f1 && cat f2) >> f3
file f3 is the result

Jean-Luc