Extract filename from multiple lines in unix - sed

Question

I'm trying to extract the name of the file name that has been generated by a Java program. This Java program spits out multiple lines and I know exactly what the format of the file name is going to be. The information text that the Java program is spitting out is as follows:
ABCASJASLEKJASDFALDSF
Generated file YANNANI-0008876_17.xml.
TDSFALSFJLSDJF;
I'm capturing the output in a variable and then applying a sed operator in the following format:
sed -n 's/.*\(YANNANI.\([[:digit:]]\).\([xml]\)*\)/\1/p'
The result set is:
YANNANI-0008876_17.xml.
However, my problem is that want the extraction of the filename to stop at .xml. The last dot should never be extracted.
Is there a way to do this using sed?

Answer 1

Let's look at what your capture group actually captures:
$ grep 'YANNANI.\([[:digit:]]\).\([xml]\)*' infile
Generated file YANNANI-0008876_17.xml.
That's probably not what you intended:
\([[:digit:]]\) captures just a single digit (and the capture group around it doesn't do anything)
\([xml]\)* is "any of x, m or l, 0 or more times", so it matches the empty string (as above – or the line wouldn't match at all!), x, xx, lll, mxxxxxmmmmlxlxmxlmxlm, xml, ...
There is no way the final period is removed because you don't match anything after the capture groups
What would make sense instead:
Match "digits or underscores, 0 or more": [[:digit:]_]*
Match .xml, literally (escape the period): \.xml
Make sure the rest of the line (just the period, in this case) is matched by adding .* after the capture group
So the regex for the string you'd like to extract becomes
$ grep 'YANNANI.[[:digit:]_]*\.xml' infile
Generated file YANNANI-0008876_17.xml.
and to remove everything else on the line using sed, we surround regex with .*\( ... \).*:
$ sed -n 's/.*\(YANNANI.[[:digit:]_]*\.xml\).*/\1/p' infile
YANNANI-0008876_17.xml
This assumes you really meant . after YANNANI (any character).

Answer 2

You can call sed twice: first in printing and then in replacement mode:
sed -n 's/.*\(YANNANI.\([[:digit:]]\).\([xml]\)*\)/\1/p' | sed 's/\.$//g'
the last sed will remove all the last . at the end of all the lines fetched by your first sed
or you can go for a awk solution as you prefer:
awk '/.*YANNANI.[0-9]+.[0-9]+.xml/{print substr($NF,1,length($NF)-1)}'
this will print the last field (and truncate the last char of it using substr) of all the lines that do match your regex.