Bash Script Variable Problem

jimmy512 · 05-10-2007, 02:20 PM

Hi. I have got a bit of a problem that I need some help with, and it has been bugging me all afternoon. I need to add the contents of a variable to every line in a text file, using a bash script. For example, if the original file contained:

Code:

World
World

and the variable contained something like "Hello", how would I go about producing something like this:

Code:

Hello World
Hello World

(I am not really concerned about the space in the middle.)

It has to use a variable, because the variable is taken from what the user types in to the computer.

I have so far tried using:

Code:

cat $VAR file1 | cat > file2

Returning:

Hello World
World

But I need the Hello on every line.

I have also tried:

Code:

sed 's/^/$VAR/g'

Returning:

$VAR World
$VAR World

I'm sorry if my question is a bit vague, but I really need help with this, and have tried everything I can think of. Thanks, in advance, for any advice or help given. It is greatly appreciated.

radoulov · 05-10-2007, 02:31 PM

Code:

$ cat file
World
World
$ var="Hello"
$ sed "s/^/$var /" file
Hello World
Hello World
$ awk '$1=v$1' v="$var " file
Hello World
Hello World

drawde83 · 05-10-2007, 02:35 PM

seems like a pretty trivial problem for something like perl
I'd write a solution but my morning coffee hasn't kicked in yet :-)
if no one else replies I'll whip something up.

lol someone else did :-) looks much simpler than what I was suggesting ;-)

bigearsbilly · 05-11-2007, 02:52 AM

Code:

billym.primadtpdev>ls -1 | perl -pe 'print "hello "'
hello access.conf
hello httpd.conf
hello httpd.conf-example
hello httpd.conf.bak
hello jserv.conf
hello jserv.properties
hello magic
hello mime.types
hello srm.conf
hello zone.properties

to replace in the file and backup

perl -pi.bak -e 'print "hello "' file

jimmy512 · 05-11-2007, 07:32 AM

Thanks for the quick replies everyone. Sorry, I'm not very experienced at writing scripts and the like. This is the first script I have written which actually does something useful. I will try all of the suggested solutions and see if they work. Thanks everyone.

bigearsbilly · 05-11-2007, 07:38 AM

or even...

xargs -n1 echo hello < file

I'll shut up now