Looking at contents.
WHAT cat DOES
Prints a whole file.
WHEN TO USE IT
Short files only.
WHY NOT LONG ONES
The output scrolls past and cannot be read.
WHAT less DOES
Shows a file a screen at a time, scrollable.
HOW TO MOVE IN IT
Arrows and page keys A slash to search n for the next match q to quit
WHY IT IS THE RIGHT DEFAULT
It handles any size, and it does not load the whole file.
WHAT head DOES
Shows the first lines, ten by default.
WHAT tail DOES
Shows the last lines.
WHAT tail WITH THE FOLLOW OPTION DOES
Keeps showing new lines as they are written.
WHY THAT IS THE MOST USED COMMAND IN TROUBLESHOOTING
It shows a log live while you reproduce a problem.
WHAT wc DOES
Counts lines, words and characters.
WHAT TO USE IT FOR
Establishing how large something is before opening it.
WHAT file DOES
Reports what kind of file something is.
WHY THAT MATTERS
Extensions lie, and opening a binary in a text viewer floods the terminal.
WHAT TO DO IF THAT HAPPENS
Run reset.
