I've now learned that grep can, halfway through grepping in a file, think
the file is suddenly binary and stop returning results.

xsv is a command line program for indexing, slicing, analyzing, splitting and joining CSV files. Commands should be simple, fast and composable:

Simple tasks should be easy.
Performance trade offs should be exposed in the CLI interface.
Composition should not come at the expense of performance.

Ncdu is a command line tool to view and analyse disk space usage on linux. It can drill down into directories and report space used by individual directories. This way it is very easy to track down space consuming files/directories. It actually allows the user to do this much faster than even a gui file manager. On the server ofcourse gui tools are not present.

Resource monitor that shows usage and stats for processor, memory, disks, network and processes.

The first of McIlroy's dicta is often paraphrased as "do one thing and do it well", which is shortened from "Make each program do one thing well. To do a new job, build afresh rather than complicate old programs by adding new 'features.'"

McIlroy's example of this dictum is:

Surprising to outsiders is the fact that UNIX compilers produce no listings: printing can be done better and more flexibly by a separate program.

If you open up a manpage for ls on mac, you’ll see that it starts with

ls [-ABCFGHLOPRSTUW@abcdefghiklmnopqrstuwx1] [file ...]

That is, the one-letter flags to ls include every lowercase letter except for {jvyz}, 14 uppercase letters, plus @ and 1. That’s 22 + 14 + 2 = 38 single-character options alone.

One of the things that makes the shell an invaluable tool is the amount of available text processing commands, and the ability to easily pipe them into each other to build complex text processing workflows. These commands can make it trivial to perform text and data analysis, convert data between different formats, filter lines, etc.

When working with text data, the philosophy is to break any complex problem you have into a set of smaller ones, and to solve each of them with a specialized tool.

Once in a while a new program really surprises me. Reminiscing a while
ago, I came up with a list of eye-opening Unix gems. Only a couple of
these programs are indispensable or much used. What singles them out is
their originality. I cannot imagine myself inventing any of them.

Meld is a visual diff tool that makes it easier to compare and merge changes in files, directories, Git repos, and more.