insert at the top of a file

saavik · 08-29-2008, 04:02 AM

Hello!

I need to insert a text at the top of a file ( in BASH ).

How can that be done ?

I need something like

# echo test >> test.txt

but at the top of the file.

THANKS

ghostdog74 · 08-29-2008, 04:11 AM

Code:

echo test > test
echo test.txt >> test
mv test test.txt

saavik · 08-29-2008, 04:13 AM

No, not really!

I have a variable lets say $a which I have to insert at the top of an existing file.

colucix · 08-29-2008, 04:22 AM

ghostdog, maybe you mean

Code:

echo test > test
cat test.txt >> test
mv test test.txt

saavik, ghostdog74 just gave you one of the infinite solutions. You can try to figure it out. If a string is the value of a shell variable, don't you think that the following are equivalent?

Code:

echo some_text

Code:

a=some_text
echo $a

ghostdog74 · 08-29-2008, 05:38 AM

Quote:

Originally Posted by colucix

ghostdog, maybe you mean

Code:

echo test > test
cat test.txt >> test
mv test test.txt

oh yes, my bad. thanks

matthewg42 · 08-29-2008, 05:44 AM

How about:

Code:

cat test.txt test > test.new
mv test.new test

fberbert · 08-29-2008, 04:20 PM

Hi,

Try this:

echo -e "text in the top\n`cat oldfile.txt`" > newfile.txt

For keeping the same filename:

echo -e "text in the top\n`cat oldfile.txt`" > newfile.txt && mv newfile.txt oldfile.txt

---
Fabio Berbert de Paula
http://www.vivaolinux.com.br

Kenhelm · 08-29-2008, 06:29 PM

This modifies the file without using a second file:-

Code:

echo "test$( < test.txt)" > test.txt