Copyright | Copyright (C) 2009 John Goerzen |
---|---|
License | GNU LGPL, version 2.1 or above |
Maintainer | John Goerzen <jgoerzen@complete.org> |
Stability | provisional |
Portability | portable |
Safe Haskell | None |
Language | Haskell98 |
Copyright (c) 2006-2009 John Goerzen, jgoerzen@complete.org
This module provides shell-like commands. Most, but not all, are designed to be used directly as part of a HSH pipeline. All may be used outside HSH entirely as well.
- abspath :: FilePath -> IO FilePath
- appendTo :: FilePath -> String -> IO String
- basename :: FilePath -> FilePath
- bracketCD :: FilePath -> IO a -> IO a
- catFrom :: [FilePath] -> Channel -> IO Channel
- catBytes :: Maybe Integer -> Channel -> IO Channel
- catBytesFrom :: Channel -> Maybe Integer -> Channel -> IO Channel
- catTo :: FilePath -> Channel -> IO Channel
- catToFIFO :: FilePath -> Channel -> IO Channel
- cd :: FilePath -> IO ()
- cut :: Integer -> Char -> String -> String
- cutR :: [Integer] -> Char -> String -> String
- dirname :: FilePath -> FilePath
- discard :: Channel -> IO Channel
- echo :: Channelizable a => a -> Channel -> IO Channel
- exit :: Int -> IO a
- glob :: FilePath -> IO [FilePath]
- grep :: String -> [String] -> [String]
- grepV :: String -> [String] -> [String]
- egrep :: String -> [String] -> [String]
- egrepV :: String -> [String] -> [String]
- joinLines :: [String] -> [String]
- lower :: String -> String
- upper :: String -> String
- mkdir :: FilePath -> FileMode -> IO ()
- numberLines :: [String] -> [String]
- pwd :: IO FilePath
- readlink :: FilePath -> IO FilePath
- readlinkabs :: FilePath -> IO FilePath
- rev :: [String] -> [String]
- revW :: [String] -> [String]
- setenv :: ShellCommand cmd => [(String, String)] -> cmd -> EnvironCommand cmd
- space :: [String] -> [String]
- unspace :: [String] -> [String]
- tac :: [String] -> [String]
- tee :: [FilePath] -> Channel -> IO Channel
- teeFIFO :: [FilePath] -> Channel -> IO Channel
- tr :: Char -> Char -> String -> String
- trd :: Char -> String -> String
- wcW :: [String] -> [String]
- wcL :: [String] -> [String]
- unsetenv :: ShellCommand cmd => [String] -> cmd -> EnvironCommand cmd
- uniq :: String -> String
Documentation
abspath :: FilePath -> IO FilePath Source #
Return the absolute path of the arg. Raises an error if the
computation is impossible. This is a thin wrapper around
System.Path.absNormPath. Unix/Linux users note:
System.Path.absNormPath is known to produce odd results when
a tilde expansion is requested; you might prefer glob
to this
function if you know your input is free of wildcards. See
https:/github.comjgoerzenhshissues/7 for details.
bracketCD :: FilePath -> IO a -> IO a Source #
Changes the current working directory to the given path, executes the given I/O action, then changes back to the original directory, even if the I/O action raised an exception.
This is an alias for the MissingH function System.Path.bracketCWD.
catFrom :: [FilePath] -> Channel -> IO Channel Source #
Load the specified files and display them, one at a time.
The special file -
means to display the input. If it is not given,
no input is processed at all.
-
may be given a maximum of one time.
See also catBytes
.
Copy data from input to output, optionally with a fixed maximum size, in bytes. Processes data using ByteStrings internally, so be aware of any possible UTF-8 conversions.
You may wish to use hSetBuffering h (BlockBuffering Nothing)
prior to calling
this function for optimal performance.
See also catFrom
, catBytesFrom
:: Channel | Handle to read from |
-> Maybe Integer | Maximum amount of data to transfer |
-> Channel | Handle for input (ignored) |
-> IO Channel |
Generic version of catBytes
; reads data from specified Channel, and
ignores stdin.
catTo :: FilePath -> Channel -> IO Channel Source #
Takes input, writes it to the specified file, and does not pass it on.
The return value is the empty string. See also catToBS
,
catToFIFO
catToFIFO :: FilePath -> Channel -> IO Channel Source #
Like catTo
, but opens the destination in ReadWriteMode instead of
ReadOnlyMode. Due to an oddity of the Haskell IO system, this is required
when writing to a named pipe (FIFO) even if you will never read from it.
This call will BLOCK all threads on open until a reader connects.
This is provided in addition to catTo
because you may want to cat to
something that you do not have permission to read from.
This function is only available on POSIX platforms.
See also catTo
cd :: FilePath -> IO () Source #
An alias for System.Directory.setCurrentDirectory.
Want to change to a user's home directory? Try this:
glob "~jgoerzen" >>= cd . head
See also bracketCD
.
cut :: Integer -> Char -> String -> String Source #
Split a list by a given character and select the nth list.
cut ' ' 2 "foo bar baz quux" -> "bar"
cutR :: [Integer] -> Char -> String -> String Source #
Split a list by a given character and select ranges of the resultant lists.
cutR [2..4] ' ' "foo bar baz quux foobar" -> "baz quux foobar" cutR [1..1000] ' ' "foo bar baz quux foobar" -> "bar baz quux foobar" cutR [-1000..1000] ' ' "foo bar baz quux foobar" -> "foo bar baz quux foobar"
Note that too large and too small indices are essentially ignored.
discard :: Channel -> IO Channel Source #
Read all input and produce no output. Discards input completely.
echo :: Channelizable a => a -> Channel -> IO Channel Source #
Takes a string and sends it on as standard output.
The input to this function is never read.
You can pass this thing a String, a ByteString, or even a Handle.
See also echoBS
.
glob :: FilePath -> IO [FilePath] Source #
Takes a pattern. Returns a list of names that match that pattern. Handles:
~username at beginning of file to expand to user's home dir ? matches exactly one character * matches zero or more characters [list] matches any character in list [!list] matches any character not in list
The result of a tilde expansion on a nonexistant username is to do no tilde expansion.
The tilde with no username equates to the current user.
Non-tilde expansion is done by the MissingH module System.Path.Glob.
grep :: String -> [String] -> [String] Source #
Search for the string in the lines. Return those that match. Same as:
grep needle = filter (isInfixOf needle)
grepV :: String -> [String] -> [String] Source #
Search for the string in the lines. Return those that do NOT match.
egrep :: String -> [String] -> [String] Source #
Search for the regexp in the lines. Return those that match.
egrepV :: String -> [String] -> [String] Source #
Search for the regexp in the lines. Return those that do NOT match.
mkdir :: FilePath -> FileMode -> IO () Source #
Creates the given directory. A value of 0o755 for mode would be typical.
An alias for System.Posix.Directory.createDirectory.
The second argument will be ignored on non-POSIX systems.
numberLines :: [String] -> [String] Source #
Number each line of a file
readlink :: FilePath -> IO FilePath Source #
Return the destination that the given symlink points to.
An alias for System.Posix.Files.readSymbolicLink
This function is only available on POSIX platforms.
readlinkabs :: FilePath -> IO FilePath Source #
As readlink
, but turns the result into an absolute path.
This function is only available on POSIX platforms.
revW :: [String] -> [String] Source #
Reverse words on each line
Reverse characters on each line (rev)
setenv :: ShellCommand cmd => [(String, String)] -> cmd -> EnvironCommand cmd Source #
Sets an environment variable, replacing an existing one if it exists.
Here's a sample ghci session to illustrate. First, let's see the defaults for some variables:
Prelude HSH> runIO $ "echo $TERM, $LANG" xterm, en_US.UTF-8
Now, let's set one:
Prelude HSH> runIO $ setenv [("TERM", "foo")] $ "echo $TERM, $LANG" foo, en_US.UTF-8
Or two:
Prelude HSH> runIO $ setenv [("TERM", "foo")] $ setenv [("LANG", "de_DE.UTF-8")] $ "echo $TERM, $LANG" foo, de_DE.UTF-8
We could also do it easier, like this:
Prelude HSH> runIO $ setenv [("TERM", "foo"), ("LANG", "de_DE.UTF-8")] $ "echo $TERM, $LANG" foo, de_DE.UTF-8
It can be combined with unsetenv:
Prelude HSH> runIO $ setenv [("TERM", "foo")] $ unsetenv ["LANG"] $ "echo $TERM, $LANG" foo,
And used with pipes:
Prelude HSH> runIO $ setenv [("TERM", "foo")] $ "echo $TERM, $LANG" -|- "tr a-z A-Z" FOO, EN_US.UTF-8
See also unsetenv
.
tee :: [FilePath] -> Channel -> IO Channel Source #
Takes input, writes it to all the specified files, and passes it on. This function does NOT buffer input.
See also catFrom
.
teeFIFO :: [FilePath] -> Channel -> IO Channel Source #
FIFO-safe version of tee
.
This call will BLOCK all threads on open until a reader connects.
This function is only available on POSIX platforms.
tr :: Char -> Char -> String -> String Source #
Translate a character x to y, like:
tr 'e' 'f'
Or, in sed,
y//