Glob-0.9.1: Globbing library

Safe HaskellNone
LanguageHaskell98

System.FilePath.Glob

Contents

Description

A library for globbing: matching patterns against file paths akin to the POSIX glob() function.

Pattern syntax is documented by compile. To toggle features at compile time, look into CompOptions. To modify matching behaviour, look into MatchOptions.

Basic usage examples:

Matching a String pattern against a FilePath:

match (compile pattern) filepath

Matching a String pattern against all paths in the current working directory:

glob pattern

Matching a String pattern against all paths in a given directory (a FilePath):

globDir1 (compile pattern) directorypath

Matching a list of String patterns against all paths in a given directory, returning the matches for each pattern as well as the paths not matched by any of the patterns:

globDir (map compile patterns) directorypath

Synopsis

Data type

data Pattern Source #

An abstract data type representing a compiled pattern.

Note that the Eq instance cannot tell you whether two patterns behave in the same way; only whether they compile to the same Pattern. For instance, compile "x" and compile "[x]" may or may not compare equal, though a match will behave the exact same way no matter which Pattern is used.

Functions

Compilation

compile :: String -> Pattern Source #

Compiles a glob pattern from its textual representation into a Pattern object.

For the most part, a character matches itself. Recognized operators are as follows:

?
Matches any character except path separators.
*
Matches any number of characters except path separators, including the empty string.
@[..\
] Matches any of the enclosed characters. Ranges of characters can be specified by separating the endpoints with a '-'. '-' or ']' can be matched by including them as the first character(s) in the list. Never matches path separators: [/] matches nothing at all. Named character classes can also be matched: [:x:] within [] specifies the class named x@, which matches certain predefined characters. See below for a full list.
@[^..\
or [!..]] Like [..], but matches any character not listed. Note that [^-x] is not the inverse of [-x], but the range [^-x]@.
<m-n>
Matches any integer in the range m to n, inclusive. The range may be open-ended by leaving out either number: "<->", for instance, matches any integer.
**/
Matches any number of characters, including path separators, excluding the empty string.

Supported character classes:

@[:alnum:\
] Equivalent to "0-9A-Za-z"@.
@[:alpha:\
] Equivalent to "A-Za-z"@.
@[:blank:\
] Equivalent to "\t "@.
@[:cntrl:\
] Equivalent to "\0-\x1f\x7f"@.
@[:digit:\
] Equivalent to "0-9"@.
@[:graph:\
] Equivalent to "!-~"@.
@[:lower:\
] Equivalent to "a-z"@.
@[:print:\
] Equivalent to " -~"@.
@[:punct:\
] Equivalent to "!-/:-@[-`{-~"@.
@[:space:\
] Equivalent to "\t-\r "@.
@[:upper:\
] Equivalent to "A-Z"@.
@[:xdigit:\
] Equivalent to "0-9A-Fa-f"@.

Note that path separators (typically '/') have to be matched explicitly or using the **/ pattern. In addition, extension separators (typically '.') have to be matched explicitly at the beginning of the pattern or after any path separator.

If a system supports multiple path separators, any one of them will match any of them. For instance, on Windows, '/' will match itself as well as '\'.

Error recovery will be performed: erroneous operators will not be considered operators, but matched as literal strings. Such operators include:

  • An empty [] or [^] or [!]
  • A [ or < without a matching ] or >
  • A malformed <>: e.g. nonnumeric characters or no hyphen

So, e.g. [] will match the string "[]".

decompile :: Pattern -> String Source #

Decompiles a Pattern object into its textual representation: essentially the inverse of compile.

Note, however, that due to internal optimization, decompile . compile is not the identity function. Instead, compile . decompile is.

Be careful with CompOptions: decompile always produces a String which can be passed to compile to get back the same Pattern. compileWith options . decompile is not the identity function unless options is compDefault.

simplify :: Pattern -> Pattern Source #

Simplifies a Pattern object: removes redundant "./", for instance. The resulting Pattern matches the exact same input as the original one, with some differences:

  • The output of globDir will differ: for example, globbing for "./*" gives "./foo", but after simplification this'll be only "foo".
  • Decompiling the simplified Pattern will obviously not give the original.
  • The simplified Pattern is a bit faster to match with and uses less memory, since some redundant data is removed.

For the last of the above reasons, if you're performance-conscious and not using globDir, you should always simplify after calling compile.

Options

data CompOptions Source #

Options which can be passed to the tryCompileWith or compileWith functions: with these you can selectively toggle certain features at compile time.

Note that some of these options depend on each other: classes can never occur if ranges aren't allowed, for instance.

Constructors

CompOptions 

Fields

compileWith :: CompOptions -> String -> Pattern Source #

Like compile, but recognizes operators according to the given CompOptions instead of the defaults.

If an error occurs and errorRecovery is disabled, error will be called.

tryCompileWith :: CompOptions -> String -> Either String Pattern Source #

A safe version of compileWith.

If an error occurs and errorRecovery is disabled, the error message will be returned in a Left.

Predefined option sets

compDefault :: CompOptions Source #

The default set of compilation options: closest to the behaviour of the zsh shell, with errorRecovery enabled.

All options are enabled.

compPosix :: CompOptions Source #

Options for POSIX-compliance, as described in man 7 glob.

numberRanges, recursiveWildcards, and pathSepInRanges are disabled.

Matching

match :: Pattern -> FilePath -> Bool Source #

Matches the given Pattern against the given FilePath, returning True if the pattern matches and False otherwise.

globDir :: [Pattern] -> FilePath -> IO [[FilePath]] Source #

Matches each given Pattern against the contents of the given FilePath, recursively. The result contains the matched paths, grouped for each given Pattern. The results are not in any defined order.

The given directory is prepended to all the matches: the returned paths are all valid from the point of view of the current working directory.

If multiple Patterns match a single FilePath, that path will be included in multiple groups.

Two FilePaths which can be canonicalized to the same file (e.g. "foo" and "./foo") may appear separately if explicit matching on paths beginning with "." is done. Looking for ".*/*", for instance, will cause "./foo" to return as a match but "foo" to not be matched.

This function is different from a simple filter over all the contents of the directory: the matching is performed relative to the directory, so that for instance the following is true:

fmap head (globDir [compile "*"] dir) == getDirectoryContents dir

(With the exception that that glob won't match anything beginning with ..)

If the given FilePath is [], getCurrentDirectory will be used.

If the given Pattern starts with a drive (as defined by FilePath), it is not relative to the given directory and the FilePath parameter is completely ignored! Similarly, if the given Pattern starts with a path separator, only the drive part of the FilePath is used. On Posix systems these behaviours are equivalent: Patterns starting with / work relative to /. On Windows, Patterns starting with / or \ work relative only to the drive part of the FilePath and Patterns starting with absolute paths ignore the FilePath.

Note that in some cases results outside the given directory may be returned: for instance the .* pattern matches the .. directory.

Any results deeper than in the given directory are enumerated lazily, using unsafeInterleaveIO.

Directories without read permissions are returned as entries but their contents, of course, are not.

globDir1 :: Pattern -> FilePath -> IO [FilePath] Source #

A convenience wrapper on top of globDir, for when you only have one Pattern you care about. Returns only the matched paths.

glob :: String -> IO [FilePath] Source #

The simplest IO function. Finds matches to the given pattern in the current working directory. Takes a String instead of a Pattern to avoid the need for a call to compile, simplifying usage further.

Can also be seen as a convenience wrapper on top of globDir1, for when you want to work in the current directory or have a pattern referring to an absolute path.

Options

data MatchOptions Source #

Options which can be passed to the matchWith or globDirWith functions: with these you can selectively toggle certain features at matching time.

Constructors

MatchOptions 

Fields

matchWith :: MatchOptions -> Pattern -> FilePath -> Bool Source #

Like match, but applies the given MatchOptions instead of the defaults.

data GlobOptions Source #

Options which can be passed to the globDirWith function.

Constructors

GlobOptions 

Fields

globDirWith :: GlobOptions -> [Pattern] -> FilePath -> IO ([[FilePath]], Maybe [FilePath]) Source #

Like globDir, but applies the given GlobOptions instead of the defaults when matching. The first component of the returned tuple contains the matched paths, grouped for each given Pattern, and the second contains Just the unmatched paths if the given GlobOptions specified that unmatched files should be included, or otherwise Nothing.

Predefined option sets

matchDefault :: MatchOptions Source #

The default set of execution options: closest to the behaviour of the zsh shell.

Currently identical to matchPosix.

matchPosix :: MatchOptions Source #

Options for POSIX-compliance, as described in man 7 glob.

ignoreDotSlash is enabled, the rest are disabled.

globDefault :: GlobOptions Source #

The default set of globbing options: uses the default matching options, and does not include unmatched files.

Miscellaneous

commonDirectory :: Pattern -> (FilePath, Pattern) Source #

Factors out the directory component of a Pattern. Useful in conjunction with globDir.

Preserves the number of path separators: commonDirectory (compile "foo///bar") becomes ("foo///", compile "bar").

isLiteral :: Pattern -> Bool Source #

Returns True iff the given Pattern is a literal file path, i.e. it has no wildcards, character ranges, etc.