- Anatomy of a typical command:
commandname [options] arg1 arg2 ...
- Options in Unix use the "-" instead of the "/" in DOS
- Options are specific to the command, there are some
conventions but there are exceptions
- Single letter options can often be combined into one:
ls -l -a -r -t is equivalent to
ls -lart
- POSIX options use
-- and are readable words;
e.g. --help
- Some commands are built into the shell (pushd, popd,
dirs, ...)
- Some commands are small programs provided by the operating
system (pwd, ls, mv, cp, ... )