Count lines below grep and include filename in output

Question

I would like to count the number of lines below a sed command and append filename to the output.

Sample file.txt

Aaaaaaa
Bbbbbbb
Ccccccc
Ddddddd

I would like to grep Bbbbbb and find the number of line below and output the number plus the filename

I tried this cat ${samplename}.txt|sed -n 'Bbbbbbb/,$p'| wc -l but the filename is not in the output

Answer 1

In order to know the line where "Bbbbb" is found:

grep -n "Bbbbb" file.txt | cut -d ':' -f 1
  // grep -n adds line number in front of the search result, this is followed by a colon.
  // You get that number by splitting over that colon and take the first field.
  

In order to know the amount of lines in a file:

wc -l file.txt

In order to perform calculations:

echo $((43 - 7))

Just combine everything :-)
Have fun