readFile

The readFile function reads a file and returns the contents of the file as a string. The file is read lazily, on demand, as with getContents. This operation may fail with the same errors as hGetContents and openFile.

Examples

>>> readFile "~/hello_world"
"Greetings!"

>>> take 5 <$> readFile "/dev/zero"
"\NUL\NUL\NUL\NUL\NUL"

Read an entire file strictly into a ByteString.

Read an entire file lazily into a ByteString. The Handle will be held open until EOF is encountered. Note that this function's implementation relies on hGetContents. The reader is advised to read its documentation.

The readFile function reads a file and returns the contents of the file as a string. The entire file is read strictly, as with getContents. Beware that this function (similarly to readFile) is locale-dependent. Unexpected system locale may cause your application to read corrupted data or throw runtime exceptions about "invalid argument (invalid byte sequence)" or "invalid argument (invalid character)". This is also slow, because GHC first converts an entire input to UTF-32, which is afterwards converted to UTF-8. If your data is UTF-8, using decodeUtf8 . readFile is a much faster and safer alternative.

The readFile function reads a file and returns the contents of the file as a string. The entire file is read strictly, as with getContents.

Read a file and return its contents as a string. The file is read lazily, as with getContents. Beware that this function (similarly to readFile) is locale-dependent. Unexpected system locale may cause your application to read corrupted data or throw runtime exceptions about "invalid argument (invalid byte sequence)" or "invalid argument (invalid character)". This is also slow, because GHC first converts an entire input to UTF-32, which is afterwards converted to UTF-8. If your data is UTF-8, using decodeUtf8 . readFile is a much faster and safer alternative.

The readFile function reads a file and returns the contents of the file as a string. The file is read lazily, on demand, as with getContents.

Read file.

>>> foreach fail BS.putStr (readFile "servant.cabal")
cabal-version:      3.0
name:               servant
...

The readFile function reads a file and returns the contents of the file as a string. The file is read strictly, as with getContents.

Warning: readFile depends on the system's locale settings and can throw unexpected exceptions.Use readFileBS or readFileLBS instead.

Read the lines of a file, using a function of the type: 'Stream (Of String) IO () -> IO a' to turn the stream into a value of type 'IO a'.

>>> S.writeFile "lines.txt" $ S.take 2 S.stdinLn
hello<Enter>
world<Enter>

>>> S.readFile "lines.txt" S.print
"hello"
"world"

Lifted readFile

Lifted readFile

Read lines from a file, automatically opening and closing the file as necessary

Read in the entire content of a binary file. This computation throws IOError on failure. See “Classifying I/O errors” in the System.IO.Error documentation for information on why the failure occured.

see readFile

Read an entire file strictly into a Bytes.

Read an entire file strictly into chunks. If reading from a regular file, this makes an effort read the file into a single chunk.

Strictly read a file into a ByteString.

Read an entire file into a chunked ByteStream IO (). The handle will be held open until EOF is encountered. The block governed by runResourceT will end with the closing of any handles opened.

>>> :! cat hello.txt
Hello world.
Goodbye world.

>>> runResourceT $ Q.stdout $ Q.readFile "hello.txt"
Hello world.
Goodbye world.