Replacing variable values in html tags

Shell Programming and Scripting
1

Hi please help me with this .

I have a file test.txt with following content
$cat test.txt
<td>$test</td>
<h2>$test2</h2>

and I have a ksh with following content

$cat test.ksh

#!/bin/ksh
test=3
test2=4
while read line
do
echo $line
done < test.html

I am expecting the output as
<td>3</td>
<h2>4</h2>

but I get the out put as

<td>$test</td>
<h2>$test2</h2>

please let me know how can I get the expected output and where my logic is failing :slight_smile:

2

It doesn't work because shell doens't do that. It doesn't evaluate variables inside variables inside variables inside variables -- and that's mostly a good thing, you could tie yourself in knots with that.

I'd modify the file a little bit, into this:

cat <<EOF
<td>$test</td>
<h2>$test2</h2>
EOF

Then use it like

. test.txt

That will do it.

3

Hi Corona688,

Thanks for the reply and sorry to bother you again.

I am pretty new to this and I am afraid I didn't understand the how to use the file that is modified. Please explain. I have changed the content of file to

$cat test
cat <<EOF
<td>$test</td>
<h2>$test2</h2>
EOF

But I am not sure how to use this in the script to have the variable values replaced.

4

So you must write all lines manually..
shell writes to stdoutput what just read from your file..

# test=3;test2=4
# echo "<td>$test</td>"
<td>3</td>
# echo "<td>$test2</td>"
<td>4</td>

or maybe test with sed (also manually)

# test=3;test2=4;sed 's/$test\b/'$test'/;s/$test2/'$test2'/' test.html
<td>3</td>
<h2>4</h2>

regards
ygemici

5

I have just worked around the cat and EOF,got the desired out put. Thanks for your help.