Unix’s best features is the shell’s command line. Why? Nearly every modern
operating system has a command line; we don’t use card readers with obscure
job setup cards any more. What makes Unix’s special?
shell command line allows lots of shortcuts. Some of these you’ll find in
other operating systems; some you won’t. In this chapter, we’ll introduce a
lot of these shortcuts. Among other things, we’ll discuss:
Filename completion (
Section 28.6, Section 28.7), which allows
you to type the beginning of a filename and let the shell fill in
the rest. (This is finally possible on certain Redmond-born OSes as
well, but it usually involves a registry hack or two.)
Command substitution (
Section 28.14), which
lets you use the output from one command as arguments to another.
(Note that this is different from
Process substitution in
bash, and a script named
! for other shells, lets you
put the output of a command into a temporary file and give that
filename to a process.