In the era of “big data”, large text files (GB or more) could be commonly encountered around us. A typical text editor may not be designed to deal with such large text files efficiently, and may simply get choked while attempting to open a big file, due to insufficient memory. If you are a savvy system admin, you can probably open or touch an arbitrary text file with a combination of cat, tail, grep, sed, awk, etc. In this tutorial, I will discuss more user-friendly ways to open (and possibly edit) a large text file on Linux.