-@node Command basics
-@chapter Basic overview
-
-A command shell is a means of entering verbally-formed commands. This
-is really all that it does, and every feature described in this manual
-is a means to that end. Therefore, it's important to take firm hold on
-exactly what a command is, and how it fits in the overall picture of
-things.
-
-@menu
-* Commands verbs:: Commands always begin with a verb.
-* Command arguments:: Some verbs require arguments.
-@end menu
-
-@node Commands verbs
-@section Commands verbs
-
-Commands are expressed using @dfn{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:
-
-@example
-@var{verb} [@var{arguments}]
-@end example
-
-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. @command{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 @dfn{arguments}. For example, the
-@command{echo} verb prints back whatever arguments you type. It
-requires these arguments to know what to echo. A proper use of
-@command{echo} looks like this:
-
-@example
-echo This is an example of using echo!
-@end example
-
-This script command causes the computer to echo back: ``This is an
-example of using echo!''
-
-Although command verbs are always simple words, like @command{reboot} or
-@command{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.
-
-@node Command arguments
-@section Command arguments
-
-Eshell recognizes several different kinds of command arguments:
-
-@enumerate
-@item Strings (also called textual arguments)
-@item Numbers (floating point or integer)
-@item Lisp lists
-@item Lisp symbols
-@item Emacs buffers
-@item Emacs process handles
-@end enumerate
-
-Most users need to worry only about the first two. The third, Lisp lists,
-occur very frequently, but almost always behind the scenes.
-
-Strings are the most common type of argument, and consist of nearly any
-character. Special characters---those used by Eshell
-specifically---must be preceded by a backslash (@samp{\}). When in doubt, it
-is safe to add backslashes anywhere and everywhere.
-
-Here is a more complicated @command{echo} example:
-
-@example
-echo A\ Multi-word\ Argument\ With\ A\ \$\ dollar
-@end example
-
-Beyond this, things get a bit more complicated. While not beyond the
-reach of someone wishing to learn, it is definitely beyond the scope of
-this manual to present it all in a simplistic manner. Get comfortable
-with Eshell as a basic command invocation tool, and learn more about the
-commands on your system; then come back when it all sits more familiarly
-on your mind. Have fun!
-
HCoop / bpt / emacs.git / blobdiff