GNU Info

(eshell)Commands verbs

---

Next: Command arguments Prev: Command basics Up: Command basics

---

Enter node , (file) or (file)node

Commands verbs
==============

   Commands are expressed using "script", a special shorthand language
computers can understand with no trouble.  Script is an extremely simple
language; oddly enough, this is what makes it look so complicated!
Whereas normal languages use a variety of embellishments, the form of a
script command is always:

     VERB [ARGUMENTS]

   The verb expresses what you want your computer to do.  There are a
fixed number of verbs, although this number is usually quite large.  On
the author's computer, it reaches almost 1400 in number.  But of course,
only a handful of these are really necessary.

   Sometimes, the verb is all that's written.  A verb is always a single
word, usually related to the task it performs.  `reboot' is a good
example.  Entering that on GNU/Linux will reboot the computer--assuming
you have sufficient privileges.

   Other verbs require more information.  These are usually very capable
verbs, and must be told specifically what to do.  The extra information
is given in the form of "arguments".  For example, the `echo' verb
prints back whatever arguments you type.  It requires these arguments
to know what to echo.  A proper use of `echo' looks like this:

     echo This is an example of using echo!

   This script command causes the computer to echo back: "This is an
example of using echo!"

   Although command verbs are always simple words, like `reboot' or
`echo', arguments may have a wide variety of forms.  There are textual
arguments, numerical arguments--even Lisp arguments.  Distinguishing
these different types of arguments requires special typing, for the
computer to know exactly what you mean.