Safe Haskell | None |
---|---|
Language | Haskell98 |
- sourceFindFiles :: (MonadIO m, MonadResource m) => FindOptions -> FilePath -> CondT FileEntry m a -> Producer m (FileEntry, a)
- find :: (MonadIO m, MonadResource m) => FilePath -> CondT FileEntry m a -> Producer m FilePath
- findFiles :: (MonadIO m, MonadBaseControl IO m, MonadThrow m) => FindOptions -> FilePath -> CondT FileEntry m a -> m ()
- findFilePaths :: (MonadIO m, MonadResource m) => FindOptions -> FilePath -> CondT FileEntry m a -> Producer m FilePath
- data FindOptions = FindOptions {}
- defaultFindOptions :: FindOptions
- test :: MonadIO m => CondT FileEntry m () -> FilePath -> m Bool
- ltest :: MonadIO m => CondT FileEntry m () -> FilePath -> m Bool
- stat :: MonadIO m => CondT FileEntry m FileStatus
- lstat :: MonadIO m => CondT FileEntry m FileStatus
- hasStatus :: MonadIO m => (FileStatus -> Bool) -> CondT FileEntry m ()
- glob :: Monad m => String -> CondT FileEntry m ()
- regex :: Monad m => String -> CondT FileEntry m ()
- ignoreVcs :: Monad m => CondT FileEntry m ()
- depth_ :: Monad m => CondT FileEntry m ()
- follow_ :: Monad m => CondT FileEntry m ()
- noleaf_ :: Monad m => CondT FileEntry m ()
- prune_ :: Monad m => CondT a m ()
- maxdepth_ :: Monad m => Int -> CondT FileEntry m ()
- mindepth_ :: Monad m => Int -> CondT FileEntry m ()
- ignoreErrors_ :: Monad m => CondT FileEntry m ()
- noIgnoreErrors_ :: Monad m => CondT FileEntry m ()
- amin_ :: MonadIO m => Int -> CondT FileEntry m ()
- atime_ :: MonadIO m => Int -> CondT FileEntry m ()
- anewer_ :: MonadIO m => FilePath -> CondT FileEntry m ()
- empty_ :: MonadIO m => CondT FileEntry m ()
- executable_ :: MonadIO m => CondT FileEntry m ()
- gid_ :: MonadIO m => Int -> CondT FileEntry m ()
- name_ :: Monad m => FilePath -> CondT FileEntry m ()
- getDepth :: Monad m => CondT FileEntry m Int
- filename_ :: Monad m => (FilePath -> Bool) -> CondT FileEntry m ()
- pathname_ :: Monad m => (FilePath -> Bool) -> CondT FileEntry m ()
- getFilePath :: Monad m => CondT FileEntry m FilePath
- regular :: MonadIO m => CondT FileEntry m ()
- directory :: MonadIO m => CondT FileEntry m ()
- hasMode :: MonadIO m => FileMode -> CondT FileEntry m ()
- executable :: MonadIO m => CondT FileEntry m ()
- lastAccessed_ :: MonadIO m => (UTCTime -> Bool) -> CondT FileEntry m ()
- lastModified_ :: MonadIO m => (UTCTime -> Bool) -> CondT FileEntry m ()
- (=~) :: (RegexMaker Regex CompOption ExecOption source, RegexContext Regex source1 target) => source1 -> source -> target
- data FileEntry = FileEntry {
- entryPath :: !FilePath
- entryDepth :: !Int
- entryFindOptions :: !FindOptions
- entryStatus :: !(Maybe FileStatus)
Introduction
- *find-conduit** is essentially a souped version of GNU find for Haskell, using a DSL to provide both ease of us, and extensive flexbility.
In its simplest form, let's compare some uses of find to find-conduit. Bear in mind that the result of the find function is a conduit, so you're expected to either sink it to a list, or operate on the file paths as they are yielded.
Basic comparison with GNU find
A typical find command:
find src -name '*.hs' -type f -print
Would in find-conduit be:
find "src" (glob "*.hs" <> regular) $$ mapM_C (liftIO . print)
The glob
predicate matches the file basename against the globbing pattern,
while the regular
predicate matches plain files.
A more complicated example:
find . -size +100M -perm 644 -mtime 1
Now in find-conduit:
let megs = 1024 * 1024 days = 86400 now <- liftIO getCurrentTime find "." ( fileSize (> 100*megs) <> hasMode 0o644 <> lastModified (> addUTCTime now (-(1*days))) )
Appending predicates like this expressing an "and" relationship. Use <|>
to
express "or". You can also negate any predicate:
find "." (not_ (hasMode 0o644))
By default, predicates, whether matching or not, will allow recursion into
directories. In order to express that matching predicate should disallow
recursion, use prune
:
find "." (prune (depth (> 2)))
This is the same as using '-maxdepth 2' in find.
find "." (prune (filename_ (== "dist")))
This is the same as:
find . \( -name dist -prune \) -o -print
Performance
find-conduit strives to make file-finding a well performing operation. To this end, a composed Predicate will only call stat once per entry being considered; and if you prune a directory, it is not traversed at all.
By default, find
calls stat for every file before it applies the predicate,
in order to ensure that only one such call is needed. Sometimes, however, you
know just from the FilePath that you don't want to consider a certain file, or
you want to prune a directory tree.
To support these types of optimized queries, a variant of find is provided
called findWithPreFilter
. This takes two predicates: one that is applied to
only the FilePath, before stat (or lstat) is called; and one that is applied
to the full file information after the stat.
Other notes
See Cond
for more details on the Monad used to build predicates.
Finding functions
sourceFindFiles :: (MonadIO m, MonadResource m) => FindOptions -> FilePath -> CondT FileEntry m a -> Producer m (FileEntry, a) Source
Find file entries in a directory tree, recursively, applying the given
recursion predicate to the search. This conduit yields pairs of type
(FileEntry, a)
, where is the return value from the predicate at each
step.
find :: (MonadIO m, MonadResource m) => FilePath -> CondT FileEntry m a -> Producer m FilePath Source
Calls findFilePaths
with the default set of finding options.
Equivalent to findFilePaths defaultFindOptions
.
findFiles :: (MonadIO m, MonadBaseControl IO m, MonadThrow m) => FindOptions -> FilePath -> CondT FileEntry m a -> m () Source
findFilePaths :: (MonadIO m, MonadResource m) => FindOptions -> FilePath -> CondT FileEntry m a -> Producer m FilePath Source
data FindOptions Source
FindOptions | |
|
test :: MonadIO m => CondT FileEntry m () -> FilePath -> m Bool Source
Test a file path using the same type of predicate that is accepted by
findFiles
.
ltest :: MonadIO m => CondT FileEntry m () -> FilePath -> m Bool Source
Test a file path using the same type of predicate that is accepted by
findFiles
, but do not follow symlinks.
File path predicates
glob :: Monad m => String -> CondT FileEntry m () Source
Find every entry whose filename part matching the given filename globbing
expression. For example: glob "*.hs"
.
ignoreVcs :: Monad m => CondT FileEntry m () Source
Return all entries, except for those within version-control metadata directories (and not including the version control directory itself either).
GNU find compatibility predicates
ignoreErrors_ :: Monad m => CondT FileEntry m () Source
noIgnoreErrors_ :: Monad m => CondT FileEntry m () Source
executable_ :: MonadIO m => CondT FileEntry m () Source
File entry predicates (uses stat information)
executable :: MonadIO m => CondT FileEntry m () Source
Predicate combinators
(=~) :: (RegexMaker Regex CompOption ExecOption source, RegexContext Regex source1 target) => source1 -> source -> target
Types and type classes
FileEntry | |
|