% eddie(1)

# NAME

eddie \- run Haskell filters from the command line

# SYNOPSYS


**eddie** [ *options* ] [ *EXPRESSION* ] *FILE* ...

# DESCRIPTION


**eddie** evalutes the provided *EXPRESSION* on either the contents of
the *FILE* arguments concatenated together, or standard input if no
*FILE* arguments are present.

The `--lines`, `--files` and `--names` options can be used to cause
*expression* to be used to process each line, each file, or tuple of
`(name, content)` for each file, respectively. The `--lists` option
can be used with `--lines`, `--files` and `--names` to cause the
*files* to be processed as a list instead of one element at a time.

The `ClassyPrelude` module is used instead of the default `Prelude`
when building expressions. The default type for input and output is
`Text`, but input or both can be changed to `ByteString` with the
`--binary` and `--text` options.

Other modules may be added with the `--Module` and `--module`
options.

# OPTIONS

**--expression**
:   The **--expression** *EXPRESSION* (short form **-e** *EXPRESSION* ) option
    concatenates it's value to the Haskell expression being evaluated
    with a newline separator.  Multiple occurrences can be used to
    build up a multi-line expression.

    If no **-e** *EXPRESSION* option is present, the first non-flag argument
    will be used for the Haskell expression.

**--lines**
:   The **--lines** (short form **-l**) option causes **eddie** to
    process the input one line at a time. The *EXPRESSION* will be run
    on each line and the results concatenated together (using
    unlines).

    The command
    ```
    eddie -l EXPRESSION file ...
    ```
    is equivalent to the command
	```
    eddie "unlines . map EXPRESSION  . lines" file ...
    ```

    Note that the **--lines**, **--files** and **--names** options
    cannot be used together.

**--files**
:   The **--files** (short form **-f**) causes each file to be processed
    individually.

    Note that the **--lines**, **--files** and **--names** options
    cannot be used together.

**--names**
:   The **--names** (short form **-n**) causes each file to
    be processed individually, as a tuple of `(name, content)`.

    Note that the **--lines**, **--files** and **--names** options
    cannot be used together.

**--list**
:   The **--list** (short form **-L**) option causes **eddie** to pass
    the expression a list of lines or files.  This requires one of the
	**--list**, **--files** or **--names** options be used.

    The command
    
    ```
    eddie -l -L EXPRESSION file ...
    ```
    is equivalent to the command
    
    ```
    eddie "EXPRESSION . lines" file ...
    ```

**--binary**
:   The **--binary** (short form **-b**) option changes the data from
    `Text` to `ByteString`. This disable all processing of the input
    and output.

**--lazy**
:   The **--lazy** (no short form) option switches the data types
    to their *lazy* versions.
    
    Note that using this is **NOT** recommended unless you know what you
    are doing. It seems to break type checking, cause hangs, or
    incorrect results when used. Even if everything works as expected,
    using it improperly can drastically increase memory usage and run
    time.

**--text**
:   The **--text** (short form **-t**) option switches the output type
    back to `Text` if the **--binary** or **--lazy** option was used.

    Using **--text** without **--binary** or **--lazy** is an error.

**--input-encoding**
:   The **--input-encoding** *ENCODING* (no short form) option sets
    the encoding of the input file(s) to *ENCODING*.
    
    It is an error to use **--input-encoding** with **--binary**.

**--output-encoding**
:   The **--output-encoding** *ENCODING* (no short form) option sets
    the encoding of the output file to *ENCODING*.
    
    It is an error to use **--output-encoding** with **--binary**
    unless **--text** is also specified.

**--encoding**
:   The **--encoding** *ENCODING* (no short form) option sets the
    encoding of all text files to *ENCODING*, whether for input or
    output.

    It is an error to use **--encoding** with **--binary**
    unless **--text** is also specified.

**--module**
:   The **--module** *NAME* (short form **-m** *NAME*) option is used
    to import module *NAME* into Haskell before evaluating the
    expression.

**--Module**
:   The **--Module** *NAME*,*AS* (short form **-M** *NAME*,*AS*) option
    imports the *NAME* module using a qualified import with an as
    clause, with *AS* being the value for the as clause.

**--extension**
:   The **--extension** *EXTENSION* (short form **-X** *EXTENSION*)
    option is used to enable the named GHC extension when evaluating
    the expression.

# DIAGNOSTICS

If the command runs with no problems, eddie will exit with a status of 0.
If there are problems with the options, such that the expression is never
evaluated, then eddie will exit with a status of 1.
If Haskell returns an error - probably a compilation problem - then
eddie will exit with the status of 2.

# SEE ALSO

The wiki at <https://chiselapp.com/user/mwm/repository/eddie/wcontent>
for examples.

# BUGS

See the issues list at <https://chiselapp.com/user/mwm/repository/eddie/rptview?rn=1>.

# AUTHOR

Mike Meyer <mwm@mired.org>