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linguist/samples/Nit/file.nit
Lucas Bajolet 163ea9ecdd Added a few samples for the Nit language
Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
2015-01-08 10:52:45 -05:00

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# This file is part of NIT ( http://www.nitlanguage.org ).
#
# Copyright 2004-2008 Jean Privat <jean@pryen.org>
# Copyright 2008 Floréal Morandat <morandat@lirmm.fr>
# Copyright 2008 Jean-Sébastien Gélinas <calestar@gmail.com>
#
# This file is free software, which comes along with NIT. This software is
# distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
# PARTICULAR PURPOSE. You can modify it is you want, provided this header
# is kept unaltered, and a notification of the changes is added.
# You are allowed to redistribute it and sell it, alone or is a part of
# another product.
# File manipulations (create, read, write, etc.)
module file
intrude import stream
intrude import ropes
import string_search
import time
in "C Header" `{
#include <dirent.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <poll.h>
#include <errno.h>
`}
# File Abstract Stream
abstract class FStream
super IOS
# The path of the file.
var path: nullable String = null
# The FILE *.
private var file: nullable NativeFile = null
fun file_stat: FileStat do return _file.file_stat
# File descriptor of this file
fun fd: Int do return _file.fileno
end
# File input stream
class IFStream
super FStream
super BufferedIStream
super PollableIStream
# Misc
# Open the same file again.
# The original path is reused, therefore the reopened file can be a different file.
fun reopen
do
if not eof and not _file.address_is_null then close
_file = new NativeFile.io_open_read(path.to_cstring)
if _file.address_is_null then
last_error = new IOError("Error: Opening file at '{path.as(not null)}' failed with '{sys.errno.strerror}'")
end_reached = true
return
end
end_reached = false
_buffer_pos = 0
_buffer.clear
end
redef fun close
do
if _file.address_is_null then return
var i = _file.io_close
_buffer.clear
end_reached = true
end
redef fun fill_buffer
do
var nb = _file.io_read(_buffer.items, _buffer.capacity)
if nb <= 0 then
end_reached = true
nb = 0
end
_buffer.length = nb
_buffer_pos = 0
end
# End of file?
redef var end_reached: Bool = false
# Open the file at `path` for reading.
init open(path: String)
do
self.path = path
prepare_buffer(10)
_file = new NativeFile.io_open_read(path.to_cstring)
if _file.address_is_null then
last_error = new IOError("Error: Opening file at '{path}' failed with '{sys.errno.strerror}'")
end_reached = true
end
end
init from_fd(fd: Int) do
self.path = ""
prepare_buffer(10)
_file = fd_to_stream(fd, read_only)
if _file.address_is_null then
last_error = new IOError("Error: Converting fd {fd} to stream failed with '{sys.errno.strerror}'")
end_reached = true
end
end
end
# File output stream
class OFStream
super FStream
super OStream
redef fun write(s)
do
if last_error != null then return
if not _is_writable then
last_error = new IOError("Cannot write to non-writable stream")
return
end
if s isa FlatText then
write_native(s.to_cstring, s.length)
else
for i in s.substrings do write_native(i.to_cstring, i.length)
end
end
redef fun close
do
if _file.address_is_null then
last_error = new IOError("Cannot close non-existing write stream")
_is_writable = false
return
end
var i = _file.io_close
_is_writable = false
end
redef var is_writable = false
# Write `len` bytes from `native`.
private fun write_native(native: NativeString, len: Int)
do
if last_error != null then return
if not _is_writable then
last_error = new IOError("Cannot write to non-writable stream")
return
end
if _file.address_is_null then
last_error = new IOError("Writing on a null stream")
_is_writable = false
return
end
var err = _file.io_write(native, len)
if err != len then
# Big problem
last_error = new IOError("Problem in writing : {err} {len} \n")
end
end
# Open the file at `path` for writing.
init open(path: String)
do
_file = new NativeFile.io_open_write(path.to_cstring)
if _file.address_is_null then
last_error = new IOError("Error: Opening file at '{path}' failed with '{sys.errno.strerror}'")
self.path = path
is_writable = false
end
self.path = path
_is_writable = true
end
# Creates a new File stream from a file descriptor
init from_fd(fd: Int) do
self.path = ""
_file = fd_to_stream(fd, wipe_write)
_is_writable = true
if _file.address_is_null then
last_error = new IOError("Error: Opening stream from file descriptor {fd} failed with '{sys.errno.strerror}'")
_is_writable = false
end
end
end
redef interface Object
private fun read_only: NativeString do return "r".to_cstring
private fun wipe_write: NativeString do return "w".to_cstring
private fun fd_to_stream(fd: Int, mode: NativeString): NativeFile `{
return fdopen(fd, mode);
`}
# returns first available stream to read or write to
# return null on interruption (possibly a signal)
protected fun poll( streams : Sequence[FStream] ) : nullable FStream
do
var in_fds = new Array[Int]
var out_fds = new Array[Int]
var fd_to_stream = new HashMap[Int,FStream]
for s in streams do
var fd = s.fd
if s isa IFStream then in_fds.add( fd )
if s isa OFStream then out_fds.add( fd )
fd_to_stream[fd] = s
end
var polled_fd = intern_poll( in_fds, out_fds )
if polled_fd == null then
return null
else
return fd_to_stream[polled_fd]
end
end
private fun intern_poll(in_fds: Array[Int], out_fds: Array[Int]) : nullable Int is extern import Array[Int].length, Array[Int].[], Int.as(nullable Int) `{
int in_len, out_len, total_len;
struct pollfd *c_fds;
sigset_t sigmask;
int i;
int first_polled_fd = -1;
int result;
in_len = Array_of_Int_length( in_fds );
out_len = Array_of_Int_length( out_fds );
total_len = in_len + out_len;
c_fds = malloc( sizeof(struct pollfd) * total_len );
/* input streams */
for ( i=0; i<in_len; i ++ ) {
int fd;
fd = Array_of_Int__index( in_fds, i );
c_fds[i].fd = fd;
c_fds[i].events = POLLIN;
}
/* output streams */
for ( i=0; i<out_len; i ++ ) {
int fd;
fd = Array_of_Int__index( out_fds, i );
c_fds[i].fd = fd;
c_fds[i].events = POLLOUT;
}
/* poll all fds, unlimited timeout */
result = poll( c_fds, total_len, -1 );
if ( result > 0 ) {
/* analyse results */
for ( i=0; i<total_len; i++ )
if ( c_fds[i].revents & c_fds[i].events || /* awaited event */
c_fds[i].revents & POLLHUP ) /* closed */
{
first_polled_fd = c_fds[i].fd;
break;
}
return Int_as_nullable( first_polled_fd );
}
else if ( result < 0 )
fprintf( stderr, "Error in Stream:poll: %s\n", strerror( errno ) );
return null_Int();
`}
end
###############################################################################
class Stdin
super IFStream
init do
_file = new NativeFile.native_stdin
path = "/dev/stdin"
prepare_buffer(1)
end
redef fun poll_in: Bool is extern "file_stdin_poll_in"
end
class Stdout
super OFStream
init do
_file = new NativeFile.native_stdout
path = "/dev/stdout"
_is_writable = true
end
end
class Stderr
super OFStream
init do
_file = new NativeFile.native_stderr
path = "/dev/stderr"
_is_writable = true
end
end
###############################################################################
redef class Streamable
# Like `write_to` but take care of creating the file
fun write_to_file(filepath: String)
do
var stream = new OFStream.open(filepath)
write_to(stream)
stream.close
end
end
redef class String
# return true if a file with this names exists
fun file_exists: Bool do return to_cstring.file_exists
# The status of a file. see POSIX stat(2).
fun file_stat: FileStat do return to_cstring.file_stat
# The status of a file or of a symlink. see POSIX lstat(2).
fun file_lstat: FileStat do return to_cstring.file_lstat
# Remove a file, return true if success
fun file_delete: Bool do return to_cstring.file_delete
# Copy content of file at `self` to `dest`
fun file_copy_to(dest: String)
do
var input = new IFStream.open(self)
var output = new OFStream.open(dest)
while not input.eof do
var buffer = input.read(1024)
output.write buffer
end
input.close
output.close
end
# Remove the trailing extension `ext`.
#
# `ext` usually starts with a dot but could be anything.
#
# assert "file.txt".strip_extension(".txt") == "file"
# assert "file.txt".strip_extension("le.txt") == "fi"
# assert "file.txt".strip_extension("xt") == "file.t"
#
# if `ext` is not present, `self` is returned unmodified.
#
# assert "file.txt".strip_extension(".tar.gz") == "file.txt"
fun strip_extension(ext: String): String
do
if has_suffix(ext) then
return substring(0, length - ext.length)
end
return self
end
# Extract the basename of a path and remove the extension
#
# assert "/path/to/a_file.ext".basename(".ext") == "a_file"
# assert "path/to/a_file.ext".basename(".ext") == "a_file"
# assert "path/to".basename(".ext") == "to"
# assert "path/to/".basename(".ext") == "to"
# assert "path".basename("") == "path"
# assert "/path".basename("") == "path"
# assert "/".basename("") == "/"
# assert "".basename("") == ""
fun basename(ext: String): String
do
var l = length - 1 # Index of the last char
while l > 0 and self.chars[l] == '/' do l -= 1 # remove all trailing `/`
if l == 0 then return "/"
var pos = chars.last_index_of_from('/', l)
var n = self
if pos >= 0 then
n = substring(pos+1, l-pos)
end
return n.strip_extension(ext)
end
# Extract the dirname of a path
#
# assert "/path/to/a_file.ext".dirname == "/path/to"
# assert "path/to/a_file.ext".dirname == "path/to"
# assert "path/to".dirname == "path"
# assert "path/to/".dirname == "path"
# assert "path".dirname == "."
# assert "/path".dirname == "/"
# assert "/".dirname == "/"
# assert "".dirname == "."
fun dirname: String
do
var l = length - 1 # Index of the last char
while l > 0 and self.chars[l] == '/' do l -= 1 # remove all trailing `/`
var pos = chars.last_index_of_from('/', l)
if pos > 0 then
return substring(0, pos)
else if pos == 0 then
return "/"
else
return "."
end
end
# Return the canonicalized absolute pathname (see POSIX function `realpath`)
fun realpath: String do
var cs = to_cstring.file_realpath
var res = cs.to_s_with_copy
# cs.free_malloc # FIXME memory leak
return res
end
# Simplify a file path by remove useless ".", removing "//", and resolving ".."
# ".." are not resolved if they start the path
# starting "/" is not removed
# trainling "/" is removed
#
# Note that the method only wonrk on the string:
# * no I/O access is performed
# * the validity of the path is not checked
#
# assert "some/./complex/../../path/from/../to/a////file//".simplify_path == "path/to/a/file"
# assert "../dir/file".simplify_path == "../dir/file"
# assert "dir/../../".simplify_path == ".."
# assert "dir/..".simplify_path == "."
# assert "//absolute//path/".simplify_path == "/absolute/path"
# assert "//absolute//../".simplify_path == "/"
fun simplify_path: String
do
var a = self.split_with("/")
var a2 = new Array[String]
for x in a do
if x == "." then continue
if x == "" and not a2.is_empty then continue
if x == ".." and not a2.is_empty and a2.last != ".." then
a2.pop
continue
end
a2.push(x)
end
if a2.is_empty then return "."
if a2.length == 1 and a2.first == "" then return "/"
return a2.join("/")
end
# Correctly join two path using the directory separator.
#
# Using a standard "{self}/{path}" does not work in the following cases:
#
# * `self` is empty.
# * `path` ends with `'/'`.
# * `path` starts with `'/'`.
#
# This method ensures that the join is valid.
#
# assert "hello".join_path("world") == "hello/world"
# assert "hel/lo".join_path("wor/ld") == "hel/lo/wor/ld"
# assert "".join_path("world") == "world"
# assert "hello".join_path("/world") == "/world"
# assert "hello/".join_path("world") == "hello/world"
# assert "hello/".join_path("/world") == "/world"
#
# Note: You may want to use `simplify_path` on the result.
#
# Note: This method works only with POSIX paths.
fun join_path(path: String): String
do
if path.is_empty then return self
if self.is_empty then return path
if path.chars[0] == '/' then return path
if self.last == '/' then return "{self}{path}"
return "{self}/{path}"
end
# Convert the path (`self`) to a program name.
#
# Ensure the path (`self`) will be treated as-is by POSIX shells when it is
# used as a program name. In order to do that, prepend `./` if needed.
#
# assert "foo".to_program_name == "./foo"
# assert "/foo".to_program_name == "/foo"
# assert "".to_program_name == "./" # At least, your shell will detect the error.
fun to_program_name: String do
if self.has_prefix("/") then
return self
else
return "./{self}"
end
end
# Alias for `join_path`
#
# assert "hello" / "world" == "hello/world"
# assert "hel/lo" / "wor/ld" == "hel/lo/wor/ld"
# assert "" / "world" == "world"
# assert "/hello" / "/world" == "/world"
#
# This operator is quite useful for chaining changes of path.
# The next one being relative to the previous one.
#
# var a = "foo"
# var b = "/bar"
# var c = "baz/foobar"
# assert a/b/c == "/bar/baz/foobar"
fun /(path: String): String do return join_path(path)
# Returns the relative path needed to go from `self` to `dest`.
#
# assert "/foo/bar".relpath("/foo/baz") == "../baz"
# assert "/foo/bar".relpath("/baz/bar") == "../../baz/bar"
#
# If `self` or `dest` is relative, they are considered relatively to `getcwd`.
#
# In some cases, the result is still independent of the current directory:
#
# assert "foo/bar".relpath("..") == "../../.."
#
# In other cases, parts of the current directory may be exhibited:
#
# var p = "../foo/bar".relpath("baz")
# var c = getcwd.basename("")
# assert p == "../../{c}/baz"
#
# For path resolution independent of the current directory (eg. for paths in URL),
# or to use an other starting directory than the current directory,
# just force absolute paths:
#
# var start = "/a/b/c/d"
# var p2 = (start/"../foo/bar").relpath(start/"baz")
# assert p2 == "../../d/baz"
#
#
# Neither `self` or `dest` has to be real paths or to exist in directories since
# the resolution is only done with string manipulations and without any access to
# the underlying file system.
#
# If `self` and `dest` are the same directory, the empty string is returned:
#
# assert "foo".relpath("foo") == ""
# assert "foo/../bar".relpath("bar") == ""
#
# The empty string and "." designate both the current directory:
#
# assert "".relpath("foo/bar") == "foo/bar"
# assert ".".relpath("foo/bar") == "foo/bar"
# assert "foo/bar".relpath("") == "../.."
# assert "/" + "/".relpath(".") == getcwd
fun relpath(dest: String): String
do
var cwd = getcwd
var from = (cwd/self).simplify_path.split("/")
if from.last.is_empty then from.pop # case for the root directory
var to = (cwd/dest).simplify_path.split("/")
if to.last.is_empty then to.pop # case for the root directory
# Remove common prefixes
while not from.is_empty and not to.is_empty and from.first == to.first do
from.shift
to.shift
end
# Result is going up in `from` with ".." then going down following `to`
var from_len = from.length
if from_len == 0 then return to.join("/")
var up = "../"*(from_len-1) + ".."
if to.is_empty then return up
var res = up + "/" + to.join("/")
return res
end
# Create a directory (and all intermediate directories if needed)
fun mkdir
do
var dirs = self.split_with("/")
var path = new FlatBuffer
if dirs.is_empty then return
if dirs[0].is_empty then
# it was a starting /
path.add('/')
end
for d in dirs do
if d.is_empty then continue
path.append(d)
path.add('/')
path.to_s.to_cstring.file_mkdir
end
end
# Delete a directory and all of its content, return `true` on success
#
# Does not go through symbolic links and may get stuck in a cycle if there
# is a cycle in the filesystem.
fun rmdir: Bool
do
var ok = true
for file in self.files do
var file_path = self.join_path(file)
var stat = file_path.file_lstat
if stat.is_dir then
ok = file_path.rmdir and ok
else
ok = file_path.file_delete and ok
end
stat.free
end
# Delete the directory itself
if ok then to_cstring.rmdir
return ok
end
# Change the current working directory
#
# "/etc".chdir
# assert getcwd == "/etc"
# "..".chdir
# assert getcwd == "/"
#
# TODO: errno
fun chdir do to_cstring.file_chdir
# Return right-most extension (without the dot)
#
# Only the last extension is returned.
# There is no special case for combined extensions.
#
# assert "file.txt".file_extension == "txt"
# assert "file.tar.gz".file_extension == "gz"
#
# For file without extension, `null` is returned.
# Hoever, for trailing dot, `""` is returned.
#
# assert "file".file_extension == null
# assert "file.".file_extension == ""
#
# The starting dot of hidden files is never considered.
#
# assert ".file.txt".file_extension == "txt"
# assert ".file".file_extension == null
fun file_extension: nullable String
do
var last_slash = chars.last_index_of('.')
if last_slash > 0 then
return substring( last_slash+1, length )
else
return null
end
end
# returns files contained within the directory represented by self
fun files : Set[ String ] is extern import HashSet[String], HashSet[String].add, NativeString.to_s, String.to_cstring, HashSet[String].as(Set[String]) `{
char *dir_path;
DIR *dir;
dir_path = String_to_cstring( recv );
if ((dir = opendir(dir_path)) == NULL)
{
perror( dir_path );
exit( 1 );
}
else
{
HashSet_of_String results;
String file_name;
struct dirent *de;
results = new_HashSet_of_String();
while ( ( de = readdir( dir ) ) != NULL )
if ( strcmp( de->d_name, ".." ) != 0 &&
strcmp( de->d_name, "." ) != 0 )
{
file_name = NativeString_to_s( strdup( de->d_name ) );
HashSet_of_String_add( results, file_name );
}
closedir( dir );
return HashSet_of_String_as_Set_of_String( results );
}
`}
end
redef class NativeString
private fun file_exists: Bool is extern "string_NativeString_NativeString_file_exists_0"
private fun file_stat: FileStat is extern "string_NativeString_NativeString_file_stat_0"
private fun file_lstat: FileStat `{
struct stat* stat_element;
int res;
stat_element = malloc(sizeof(struct stat));
res = lstat(recv, stat_element);
if (res == -1) return NULL;
return stat_element;
`}
private fun file_mkdir: Bool is extern "string_NativeString_NativeString_file_mkdir_0"
private fun rmdir: Bool `{ return rmdir(recv); `}
private fun file_delete: Bool is extern "string_NativeString_NativeString_file_delete_0"
private fun file_chdir is extern "string_NativeString_NativeString_file_chdir_0"
private fun file_realpath: NativeString is extern "file_NativeString_realpath"
end
# This class is system dependent ... must reify the vfs
extern class FileStat `{ struct stat * `}
# Returns the permission bits of file
fun mode: Int is extern "file_FileStat_FileStat_mode_0"
# Returns the last access time
fun atime: Int is extern "file_FileStat_FileStat_atime_0"
# Returns the last status change time
fun ctime: Int is extern "file_FileStat_FileStat_ctime_0"
# Returns the last modification time
fun mtime: Int is extern "file_FileStat_FileStat_mtime_0"
# Returns the size
fun size: Int is extern "file_FileStat_FileStat_size_0"
# Returns true if it is a regular file (not a device file, pipe, sockect, ...)
fun is_reg: Bool `{ return S_ISREG(recv->st_mode); `}
# Returns true if it is a directory
fun is_dir: Bool `{ return S_ISDIR(recv->st_mode); `}
# Returns true if it is a character device
fun is_chr: Bool `{ return S_ISCHR(recv->st_mode); `}
# Returns true if it is a block device
fun is_blk: Bool `{ return S_ISBLK(recv->st_mode); `}
# Returns true if the type is fifo
fun is_fifo: Bool `{ return S_ISFIFO(recv->st_mode); `}
# Returns true if the type is a link
fun is_lnk: Bool `{ return S_ISLNK(recv->st_mode); `}
# Returns true if the type is a socket
fun is_sock: Bool `{ return S_ISSOCK(recv->st_mode); `}
end
# Instance of this class are standard FILE * pointers
private extern class NativeFile `{ FILE* `}
fun io_read(buf: NativeString, len: Int): Int is extern "file_NativeFile_NativeFile_io_read_2"
fun io_write(buf: NativeString, len: Int): Int is extern "file_NativeFile_NativeFile_io_write_2"
fun io_close: Int is extern "file_NativeFile_NativeFile_io_close_0"
fun file_stat: FileStat is extern "file_NativeFile_NativeFile_file_stat_0"
fun fileno: Int `{ return fileno(recv); `}
new io_open_read(path: NativeString) is extern "file_NativeFileCapable_NativeFileCapable_io_open_read_1"
new io_open_write(path: NativeString) is extern "file_NativeFileCapable_NativeFileCapable_io_open_write_1"
new native_stdin is extern "file_NativeFileCapable_NativeFileCapable_native_stdin_0"
new native_stdout is extern "file_NativeFileCapable_NativeFileCapable_native_stdout_0"
new native_stderr is extern "file_NativeFileCapable_NativeFileCapable_native_stderr_0"
end
redef class Sys
# Standard input
var stdin: PollableIStream = new Stdin is protected writable
# Standard output
var stdout: OStream = new Stdout is protected writable
# Standard output for errors
var stderr: OStream = new Stderr is protected writable
end
# Print `objects` on the standard output (`stdout`).
protected fun printn(objects: Object...)
do
sys.stdout.write(objects.to_s)
end
# Print an `object` on the standard output (`stdout`) and add a newline.
protected fun print(object: Object)
do
sys.stdout.write(object.to_s)
sys.stdout.write("\n")
end
# Read a character from the standard input (`stdin`).
protected fun getc: Char
do
return sys.stdin.read_char.ascii
end
# Read a line from the standard input (`stdin`).
protected fun gets: String
do
return sys.stdin.read_line
end
# Return the working (current) directory
protected fun getcwd: String do return file_getcwd.to_s
private fun file_getcwd: NativeString is extern "string_NativeString_NativeString_file_getcwd_0"