Shell Programming and Scripting

I'm trying simple functionality of replacing the second line of files with some other string.
Problem is these files are huge and there are too many files to process.

Could anyone please suggest me a way to replace the second line of all files with another text in a fastest possible manner.

existing line:
<ase:aseXML xmlns:ase="urn:aseXML:r22" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:aseXML:r22 http://www.nemmco.com.au/aseXML/schemas/r22/aseXML_r22.xsd">

New line required:
<ase:aseXML xmlns:ase="urn:aseXML:r22" xmlns:xsi="/dstage/data/CISdev/MSATS/Schema/XMLSchema-instance.xml" xsi:schemaLocation="urn:aseXML:r22 /dstage/data/CISdev/MSATS/Schema/aseXML_r22.xsd">

Regards
Satish

If line to replace is always in the same position in the file (ie the first two lines are always the same length), I'd use dd to do it, just dd (or head) out the first line, append the second, then dd the rest of the file on.
If thats not an option, I'd think the simplest way would be to do the following:

Code:

head -1 input.txt > output.txt
echo '<ase:aseXML xmlns:ase="urn:aseXML:r22" xmlns:xsi="/dstage/data/CISdev/MSATS/Schema/XMLSchema-instance.xml"
   xsi:schemaLocation="urn:aseXML:r22 /dstage/data/CISdev/MSATS/Schema/aseXML_r22.xsd">' >> output.txt
tail +3 input.txt >> output.txt

---------- Post updated at 05:51 PM ---------- Previous update was at 05:49 PM ----------

If the file is truly epic, you may need to stream everything, just change the head and tails to head/tail < input.txt >> output.txt (ie add the < character).

Thanks.

This solution works perfect.