Typographical conventions

Throughout this manual, we use certain typographical conventions to distinguish technical terms. In general, the conventions we use conform to those found in IEEE POSIX publications. The following table summarizes our conventions.

Reference Example
Code examples if( stream == NULL )
Command options -lR
Commands make
Environment variables PATH
File and pathnames /dev/null
Function names exit()
Keyboard chords Ctrl -Alt -Delete
Keyboard input something you type
Keyboard keys Enter
Program output login:
Programming constants NULL
Programming data types unsigned short
Programming literals 0xFF, "message string"
Variable names stdin

Single-step instructions are formatted like this:

=>> To reboot your computer, press Ctrl -Alt -Shift -Delete .

Notes, cautions, and warnings are used to highlight important messages:

Note: Notes point out something important or useful.

Caution: Cautions tell you about commands or procedures that may have unwanted or undesirable side effects.

WARNING: Warnings tell you about commands or procedures that could be dangerous to your files, your hardware, or even yourself.