Shell Programming and Scripting

Hi there,

I'm trying to write a bash script and I have some difficulties...

I have multiple files, which have the following names:
file_1.txt
file_2.txt
...
file_26.txt

Within each file there is some information, like:
(in the file_1.txt) name of the file: file_name_1_info.hdr
(in the file_2.txt) name of the file: file_name_2_info.hdr
...
(in the file_26.txt) name of the file: file_name_26_info.hdr


I need to replace the information that is included in each file with this:
(in the file_1.txt) name of the file: file_01_tag.hdr
(in the file_2.txt) name of the file: file_02_tag.hdr
...
(in the file_26.txt) name of the file: file_26_tag.hdr


I tried to use either the sed or the gsub command in a for loop, for example something like this:

Code:

for ((i=1;i<=26;i++))
do
sed 's/file_name_${i)_info.hdr/file_${i}_tag.hdr/g' file_${i}.txt > filetag_${i}.txt
done

But unfortunately it does not recognise the variable within the sed command...

Is there any way to do this? Maybe it's easy, but I'm a beginner in bash scripting!

Thanks a lot in advance!

giorgos

This should work:

Code:

#!/bin/sh

count=0

until [ $count = "26" ]; do
        count=$(expr $count + 1)
        sed 's/file_name_${count}_info.hdr/file_${count}_tag.hdr/g' file_${count}.txt > filetag_${count}.txt
done

Use double quotes around the sed code:

Code:

sed "s/file_name_${i)_info.hdr/file_${i}_tag.hdr/g" file_${i}.txt > filetag_${i}.txt

Thanks a lot! I'll test it at work and I'll let you know!!

Thank you both for your response!

It worked perfectly! Thanks a lot! You've saved me a lot of time!!!