I have a file that looks roughly like this :
[25]:0.00843832,469:0.0109533):0.00657864,((((872:0.00120503,((980:0.0001
[29]:((962:0.000580339,930:0.000580339):0.00543993 ((758:0.000598847,726:0.000598847)
position:
sites: 5 4 2 1 3 4 543 5 67 657 78 67 8 5645 6
01010010101010101010101010101011111100011
1111010010010101010101010111101000100000
00000000000000011001100101010010101011111
Now I would like to extract only those lines which start with [numeric]: from the file. It is not always only the first two, it could also be the first 7 or 8 or whatever. How would I read in this file and output a file only containing the lines with [numeric]:?