Name
SPVM::IO::File - File Stream
Description
IO::File class in SPVM represents a file stream.
Usage
use IO::File;
# Write a line
my $fh = IO::File->new("foo.txt", ">");
$fh->say("Hello");>
# Read lines
my $fh = IO::File->new("foo.txt", "<");
while (my $line = $fh->readline) {
}Super Class
Fields
FileStream
has FileStream : Sys::IO::FileStream;
A file stream associated with the file descriptoer FD.
InputLineNumber
has InputLineNumber : long;
The current line number. This value is incremented by "getline" method.
AutoFlush
has AutoFlush : protected byte;
A flag for auto flush.
Class Methods
new
static method new : IO::File ($file_name : string = undef, $open_mode : string = undef);
Creates a new IO::File object.
And opens a file given the file name $file_name and the open mode $open_mode by calling "open" method.
And returns the new object.
If $file_name is not defined, a file is not opened.
Exceptions:
Exceptions thrown by "open" method could be thrown.
See Also:
See IO#open method if you find a method ported from Perl opendir function.
new_from_fd
static method new_from_fd : IO::File ($fd : int, $open_mode : string);
Creates a new IO::File object.
And opens a file given the file descriptor $fd and the open mode $open_mode by calling "fdopen" method.
And returns the new object.
Exceptions:
Exceptions thrown by "fdopen" method could be thrown.
open
method open : void ($file_name : string, $open_mode : string);
Opens a file given the file name $file_name and the open mode $open_mode.
This method calls Sys#open method.
"FileStream" field is set to the opened file stream.
"InputLineNumber" field is set to 0.
Exceptions:
The file name $file_name must be defined. Otherwise an exception is thrown.
The open mode $open_mode must be defined. Otherwise an exception is thrown.
If a file is already opened, an exception is thrown.
Instance Methods
input_line_number
method input_line_number : long ();
Returns the value of "InputLineNumber" field.
close
method close : void;
Closes the file stream "FileStream".
This method calls Sys::IO#fclose method.
"InputLineNumber" field is set to 0.
FD field is set to -1.
Exceptions:
Exceptions thrown by Sys::IO#fclose method could be thrown.
read
method read : int ($string : mutable string, $length : int = -1, $offset : int = 0);
Reads the length $length of data from the file stream "FileStream" and store it to the offset $offset position of the string $string.
This method calls Sys#read method.
Exceptions:
Exceptions thrown by Sys#read method could be thrown.
getc
method getc : int ();
Reads a character from the file stream "FileStream", and returns the line.
This method calls Sys#getc method with the file stream "FileStream".
Exceptions:
Exceptions thrown by Sys#getc method could be thrown.
getline
method getline : string ();
Reads a line from the file stream "FileStream", incrementes the input line number "InputLineNumber" by 1, and returns the line.
A line is the part that ends with \n or EOF.
If EOF has been reached, returns undef.
This method calls Sys#readline method with the file stream "FileStream".
Exceptions:
Exceptions thrown by Sys#readline method could be thrown.
getlines
method getlines : string ();
Reads all lines from the file stream "FileStream", joins them to a string, and returns it.
This method calls "getline" method repeatedly.
If the first character is EOF, returns an empty string "".
Exceptions:
Exceptions thrown by "getline" method could be thrown.
write
method write : int ($string : string, $length : int = -1, $offset : int = 0);
Writes the length $length from the offset $offset of the string $string to the file stream "FileStream".
This method calls Sys::IO#fwrite method.
If "AutoFlush" field is a true value, thie method calls "flush" method after the write operation.
Exceptions:
Exceptions thrown by Sys::IO#fwrite method could be thrown.
flush
method flush : void ();
Flushes the write buffer.
This method calls Sys::IO#fflush method.
Exceptions:
Exceptions thrown by Sys::IO#fflush method could be thrown.
error
method error : int ();
If the file stream "FileStream" reaches the end of file, returns 1, otherwise returns 0.
This method calls Sys::IO#ferror method with the file stream "FileStream".
Exceptions:
Exceptions thrown by Sys::IO#ferror method could be thrown.
clearerr
method clearerr : void ();
Clears the error satus of the file stream "FileStream".
This method calls Sys::IO#clearerr method with the file stream "FileStream".
Exceptions:
Exceptions thrown by Sys::IO#clearerr method could be thrown.
eof
method eof : int ();
If the file stream "FileStream" reaches the end of file, returns 1, otherwise returns 0.
This method calls Sys::IO#feof method with the file stream "FileStream".
Exceptions:
Exceptions thrown by Sys::IO#feof method could be thrown.
ungetc
method ungetc : int ($c : int);
Pushes the character $c back to the file stream "FileStream" and returns the character that is actually pushed.
This method calls Sys::IO#ungetc method with the file stream "FileStream".
Exceptions:
Exceptions thrown by Sys::IO#ungetc method could be thrown.
sync
method sync : void ();
Transfers all modified in-core data of the file referred to by the file descriptor FD to the disk device.
This method calls Sys::IO#fsync method with the file descriptor FD.
Exceptions:
Exceptions thrown by Sys::IO#fsync method could be thrown.
truncate
method truncate : void ($legnth : long);
Causes the regular file named by referenced by the file descriptor FD to be truncated to a size of precisely $legnth bytes.
This method calls Sys::IO#ftruncate method with the file descriptor FD.
Exceptions:
Exceptions thrown by Sys::IO#ftruncate method could be thrown.
fdopen
protected method fdopen : void ($fd : int, $open_mode : string);
Opens a file given the file descriptor $fd and the open mode $open_mode.
This method calls Sys#fdopen method.
"FileStream" field is set to the opened file stream.
"InputLineNumber" field is set to 0.
Exceptions:
The open mode $open_mode must be defined. Otherwise an exception is thrown.
If a file is already opened, an exception is thrown.
autoflush
method autoflush : int ();
Returns the value of "AutoFlush" field.
set_autoflush
method set_autoflush : void ($autoflush : int);
Sets "AutoFlush" field to $autoflush.
See Also
Porting
This class is a Perl's IO::File porting to SPVM.
Copyright & License
Copyright (c) 2023 Yuki Kimoto
MIT License