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|
{- HSH -- The Haskell Shell
Copyright (C) 2004-2007 John Goerzen <jgoerzen@complete.org>
Please see the COPYRIGHT file
-}
{- |
Module : HSH
Copyright : Copyright (C) 2006 John Goerzen
License : GNU LGPL, version 2.1 or above
Maintainer : John Goerzen <jgoerzen@complete.org>
Stability : provisional
Portability: portable
Copyright (c) 2006 John Goerzen, jgoerzen\@complete.org
Welcome to HSH, the Haskell Shell infrastructure.
<http://software.complete.org/hsh>
HSH is designed to let you mix and match shell expressions with Haskell
programs.
Here are a few examples to get you started:
>run $ "echo /etc/pass*" :: IO String
> -> "/etc/passwd /etc/passwd-"
>
>runIO $ "ls -l" -|- "wc -l"
> -> 12
>
>runIO $ "ls -l" -|- wcL
> -> 12
>
>runIO $ ("ls", ["-l", "file with spaces.txt"])
>glob "~jgoerzen" >>= cd . head
wcL is a pure Haskell function defined in "HSH.ShellEquivs.wcL" as:
>wcL :: [String] -> [String]
>wcL inp = [show $ genericLength inp]
Here's another example:
> let countLines = (zipWith (\i line -> printf "%-5d %s" i line)
> [(1::Int)..])::([String] -> [String])
>
> runIO $ ("ls", ["-l"]) -|- countLines -|- filter (isSuffixOf "hs")
> 6 -rw-r--r-- 1 jgoerzen jgoerzen 1285 Jun 6 09:43 HSH.hs
> 11 -rw-r--r-- 1 jgoerzen jgoerzen 565 Jun 6 09:43 test.hs
To use HSH, you\'ll just want to import the HSH module. To learn more,
please see the information in "HSH.Command" and "HSH.ShellEquivs".
You can run a command with HSH in several ways:
* By using 'run' in a context that expects IO (), which will leave
the final standard output going
to the normal standard output of the program
* By using 'run' in a context that expects a String, which will
capture standard output into a buffer and present it as a String
* Any of the numerous other methods documented in 'RunResult'.
* The shortcut functions 'runIO' and 'runSL'. 'runIO' lets you run
a command and force the context IO (), which is a frequently-useful
shortcut when you don't care about the result. 'runSL' grabs the
first line of output in the result.
You can then specify a command, which could be a single command or a command
joined together with pipes.
There are many different items that make valid types; see the list of
instances of 'ShellCommand' for a full list. Here are a few:
* A simple bare string is passed to the shell for execution. The shell
will then typically expand wildcards, parse parameters, etc.
* A @(String, [String])@ tuple. The first item in the tuple gives
the name of a program to run, and the second gives its arguments.
The shell is never involved. This is ideal for passing filenames,
since there is no security risk involving special shell characters.
* A Haskell function. This function will accept input representing
its standard input and generate output to go to stdout. Function
types that are supported natively include @(String -> String)@,
@(String -> IO String)@, plus many more involving ByteStrings and functions
that take no input. See 'HSH.Command.ShellCommand' for more.
Pipes can be constructed by using the -|- operator, as illustrated above.
It is quite possible to pipe data between Haskell functions and
shell commands at will.
In addition, "HSH.ShellEquivs" provides a number of useful pure-Haskell
equivalents of regular shell commands.
For more information, please consult the other modules in HSH as well as
the HSH wiki at:
<http://software.complete.org/hsh>
-}
module HSH (
module HSH.Command,
module HSH.ShellEquivs
)
where
import HSH.Command
import HSH.ShellEquivs
|
