Get specific string
This should also work if you are looking only for numbers after Tot
[srikanth@myhost ~]$ echo "Abcd1234_Tot9012_tore.dr" | awk ' { match($0,/Tot([0-9]*)/,a); print a[1]; } '9012[srikanth@myhost ~]$ echo "Abcd1234_Tot9012.tore.dr" | awk ' { match($0,/Tot([0-9]*)/,a); print a[1]; } '9012
I know this is tagged as bash/sed but perl is clearer for this kind of task, in my opinion. In case you're interested:
perl -ne 'print $1 if /Tot([0-9]+)[._]/' input.txt-ne tells perl to loop the specified one-liner over the input file without printing anything by default.
The regex is readable as: match Tot, followed by a number, followed by either a dot or an underscore; capture the number (that's what the parens are for). As it's the first/capture group it's assigned to the $1 variable, which then is printed.