Replace character string between new lines
Clash Royale CLAN TAG #URR8PPP Replace character string between new lines I am trying to edit a file such that strings flanked by new lines are removed. My file looks like: ENSG00000000460_chr1.dat varX data data data data data varX data data data data data varX data data data data data ENSG00000005801_chr11.dat ENSG00000006007_chr16.dat ENSG00000006607_chr2.dat varX data data data data data varX data data data data data ENSG00000010219_chr12.dat ENSG00000011052_chr17.dat The output I am trying to get would delete lines which are flanked by new lines (and delete the new lines) resulting in output which looks like: ENSG00000000460_chr1.dat varX data data data data data varX data data data data data varX data data data data data ENSG00000006607_chr2.dat varX data data data data data varX data data data data data I have tried various ideas in sed, but it either returns: sed 's/[na-zA-Z0-9n]//g' file.txt | head _. . .- . . . . . . .-...