\chapter QSA Utility Framework

The QSA Utility Framework is a set of classes that extends QSA to
enable the user to read and write files, access directory structures
and start processes synchronously and asynchronously. The Utility
Framework is available in the \l QSObjectFactory subclass \l
QSUtilFactory

\omit
********************************************************************************
				class File
********************************************************************************
\endomit

\section1 File Class Reference

The \c File class provides functionallity for reading and writing
binary and text files. A \c File can be instantiated as an object,
giving the scripter complete flexibility when reading and writing files.
In addition, the \c File class provides a set of static convenence
functions for reading and writing files in one go.

Typical use of a \c File is:

\code
// Reads an entire file in one go
var log = File.read('file.log');
// Writes an entire file in one go
File.write('copy_of_file.log', log);

// Read and write a file line by line
var infile = new File('file.log');
infile.open(File.ReadOnly);

var outfile = new File('copy_of_file.log');
outfile.open(File.WriteOnly);

while (!infile.eof) {
    var line = infile.readLine();
    outfile.write( line );
}

infile.close();
outfile.close();
\endcode

\section2 Enums

\section3 AccessMode

The enum \c AccessMode is used in conjunction with \c File.open to
specify the mode in which the file is opened.

\list

\o ReadOnly; Opens the file in read-only mode. 

\o WriteOnly; Opens the file in write-only mode. If this flag is
used with \c Append, the file is not truncated; but if used on its own
(or with \c Truncate), the file is truncated.

\o ReadWrite; Opens the file in read/write mode. The file is \i not
truncated.

\o Append; Opens the file in append mode. (You must actually use
\c{(WriteOnly | Append)} to make the file writable and to go into
append mode.) This mode is very useful when you want to write
something to a log file. The file index is set to the end of the file.
Note that the result is undefined if you position the file index
manually using at() in append mode.

\o Truncate; Truncates the file. 

\o Translate; Enables carriage returns and linefeed translation
for text files under Windows.

\endlist


\section2 Static Functions

\list

\o exists( fileName : String ) : Boolean; Returns true if \c fileName
exists; otherwise returns false.

\o remove( fileName : String ); Deletes the file \c fileName if
possible; otherwise throws an exception.

\o write( fileName : String, content : String ); Writes the string \c
content to the file \c fileName if possible (completely replacing the
original contents if the file already exists); otherwise throws an
exception.

\o read( fileName : String ) : String; Reads and returns the contents of
the file \c fileName if possible; otherwise throws an exception.

\o isFile( fileName : String ) : Boolean; Returns true if \c fileName
is a file; otherwise returns false.

\o isDir( fileName : String ) : Boolean; Returns true if \c fileName
is a directory; otherwise returns false.

\endlist

\section2 Constructor

\list 

\o File( fileName : String ); Creates a file object with the with \c
fileName. If \c fileName is missing or is not a String, an exception
is thrown.

\endlist

\section2 Properties

The File object's properties are read-only.

\list 

\o name : String; The name of the file including the extension.

\o path : String; The path of the file.

\o fullName : String; The fullName of the file, including path, name, and
extension.

\o baseName : String; The name of the file, excluding its path and
extension.

\o extension : String; The file name's extension.

\o symLink : String; The expansion of the symlink if the file is a
symlink; otherwise empty;

\o exists : Boolean; True if the file exists; otherwise false.

\o readable : Boolean; True if the file is readable; otherwise false.

\o writable : Boolean; True if the file is writable; otherwise false.

\o executable : Boolean; True if the file is executable; otherwise
false.

\o hidden : Boolean; True if the file is hidden; otherwise false.

\o eof : Boolean; True if reading has reached the end of the file;
otherwise false.

\o created : Date; The creation time of the file.

\o lastModified : Date; The last modification time of the file.

\o lastRead : Date; The last time the file was read.

\o size : Number; The size of the file, in bytes.

\endlist


\section2 Member Functions

\list 

\o open( accessMode : Number ); Opens the file in the mode \c
accessMode if possible; otherwise throws an exception.

\o close(); Closes the file.

\o remove((); Deletes the file if possible; otherwise throws an
exception.

\o readByte() : Number; Reads one byte from the file if possible;
otherwise throws an exception.

\o read() : String; Returns the entire content of the file as a string
if it can be read; otherwise throws an exception.

\o readLine() : String; Reads one line from file if possible;
otherwise throws an exception. Retains any trailing whitespace.

\o readLines() : String[]; Returns the contents of the file as an
array of Strings, one for each line. Linebreaks are strippped from the
strings. If the file could not be read, an exception is thrown.

\o writeByte( byte : Number ); Writes a byte to the file is possible;
otherwise throws an exception.

\o write( data : String, length : Number ); Writes \c length number of
characters from \c data to the file if possible; otherwise throws an
exception.

\o writeLine( data : String ); Writes the line \c data to the file and
adds a linebreak. If the file could not be written \c error is
returned.

\endlist


\omit
********************************************************************************
				class Dir
********************************************************************************
\endomit

\section1 Dir Class Reference

The \c Dir class provides access to directory structures and their
contents in a platform-independent way. It provides a means of listing
directory content, creating filenames with proper path separators,
etc.

An example use of the Dir class is:

\code
var dir = new Dir;
var codeFiles = dir.entryList('*.cpp');
for (var i = 0; i < codeFiles.length; ++i) 
    print(codeFiles[i]);
\endcode

\section2 Enums

\section3 FilterSpec

This enum describes the filtering options available to Dir for
entryList(). The filter value is specified by OR-ing together values
from the following list.

\list

\o Dirs; List directories only.

\o Files; List files only.

\o Drives; List disk drives only.

\o NoSymLinks; Do not list symbolic links (ignored by operating
systems that don't support symbolic links).

\o All; List directories, files, drives and symlinks (this does not
list broken symlinks unless you specify System).

\o TypeMask; A mask for the the Dirs, Files, Drives and NoSymLinks
flags.

\o Readable; List files for which the application has read access. 

\o Writable; List files for which the application has write access. 

\o Executable; List files for which the application has execute
access. Executables must be combined with Dirs or Files.

\o RWEMask; A mask for the Readable, Writable and Executable flags.

\o Modified; Only list files that have been modified (ignored under
Unix).

\o Hidden; List hidden files (on Unix, files starting with a .). 

\o System; List system files (on Unix, FIFOs, sockets, and device
files)

\o AccessMask; A mask for the Readable, Writable, Executable Modified,
Hidden and System flags

\endlist

\section3 SortSpec

This enum describes the sort options available to Dir for
entryList(). The sort value is specified by OR-ing together values
from the following list:

\list
\o Name; Sort by name.
\o Time; Sort by time (modification time).
\o Size; Sort by file size.
\o Unsorted; Do not sort.
\o SortByMask; A Mask for Name, Time and Size.
\o DirsFirst; Put the directories first, then the files.
\o Reversed; Reverse the sort order.
\o IgnoreCase; Sort case-insensitively.
\endlist

\section2 Static Properties

\list
\o current : String; The current directory.
\o home : String; The home directory.
\o root : String; The root directory.
\o drives : String[]; An array of strings containing the drive names
(c:, d:, etc); empty on Unix.
\endlist 

\section2 Static Functions

Qt uses "/" as a directory separator throughout (although it
understands the conventions of the platform it is used on). If you
are working with paths, use "/" within your code, and use
convertSeparators() when you want to display a path to the user.

\list

\o cleanDirPath( filePath : String ) : String; Removes all multiple
directory separators "/" and resolves any "."s or ".."s found in the
path, \c filePath.

\o convertSeparators( pathName : String ) : String; Returns \c
pathName with the "/" separators converted to separators that are
appropriate for the underlying operating system.

\endlist

\section2 Constructor

\list

\o Dir( path : String ); Creates a directory object for path \c
path. If \c path is empty, the current directory is used.

\endlist

\section2 Properties

\list

\o name : String; Contains the name of the directory; this is not the
same as the path, e.g. a directory with the name "mail", might have
the path "/var/spool/mail"

\o path : String; Contains the path, this may contain symbolic links,
but never contains redundant ".", "..", or multiple separators.

\o absPath : String; Contains the absolute path (a path that starts
with "/" or with a drive specification), which may contain symbolic
links, but never contains redundant ".", "..", or multiple separators.

\o canonicalPath : String; Contains the canonical path, i.e. a path
without symbolic links or redundant "." or ".." elements.

\o readable : Boolean; True if the directory is readable; otherwise
false.

\o exists : Boolean; True if the directory exists; otherwise false.

\endlist 

\section2 Member Functions

\list

\o filePath( fileName : String ) : String; Returns the path name of
the file \c fileName in the directory.

\o absFilePath( fileName : String ) : String; Returns the absolute
path name of the file \c fileName in the directory.

\o cd( dirName : String ); Changes the Dir's directory to \c dirName
if possible; otherwise throws an exception.
 
\o cdUp(); Changes directory by moving one directory up from the
Dir's current directory if possible; otherwise throws an exception.

\o entryList( filter : String, filterSpec : Number, sortSpec : Number
) : String[]; Returns a list of the names of all the files and
directories in the directory, ordered in accordance with \c sortSpec
and filtered in accordance with \c filterSpec.

\o mkdir( dirName : String ); Creates the directory \c dirName if
possible; otherwise throws an exception.

\o mkdir(); Creates this directory if possible possible; otherwise
throws an exception.

\o mkdirs( dirName : String ); Creates the directory tree \c dirName
if possible; otherwise throws an exception.

\o mkdirs(); Creates this directory tree if possible; otherwise throws
an exception.

\o rmdir( dirName : String ); Deletes the directory \c dirName if
possible; otherwise throws an exception.

\o rmdir(); Deletes this directory if possible; otherwise throws an
exception.

\o rmdirs( dirName : String ); Deletes the directory structure \c
dirName if possible; otherwise throws an exception.

\o rmdirs(); Deletes this directory structure if possible; otherwise
throws an exception.

\o fileExists( fileName : String ) : Boolean; Returns true if the file
\c fileName exists; otherwise returns false.

\o setCurrent(); Sets the application's current working directory to
this directory if possible; otherwise throws an exception.

\endlist


\section1 Process Class Reference

The Process class is used to start external programs and to
communicate with them. The Process class can start programs
synchronously using \c Process.execute(), and asynchronously using
\c {new Process(...).start()}.

\section2 Static Properties

\list

\o stdout : String; Contains the data sent to \c stdout during the
last call to \c Process.execute(). This property is read-only.

\o stderr : String; Contains the data sent to \c stderr during the
last call to \c Process.execute(). This property is read-only.

\endlist 

\section2 Static Functions

\list

\o execute( command : String, stdin : String ); Executes \c command
synchronously and passes \c stdin to its standard input if specified.
When the program ends its output is accessible through \c
Process.stdout and \c Process.stderr. \c command can contain both the
program and command line arguments, e.g. \c{ "ls -la" }. The function
returns the executed commands return code on exit.

\o execute( command : String[], stdin : String ); Same as above,
except that \c command is an array of strings, where the first item is
the name of the program and the following items are command line
arguments. This version is useful if you have arguments that contain
spaces or other characters that would need to be quoted if you just
passed a single string command line, since it takes care of the
quoting for you.

\endlist

\section2 Constructor

\list

\o Process(); Creates a Process object without specifying the program
or any arguments. This does \i not start a process.

\o Process( command : String ); Creates a Process object that will
execute \c command. This does \i not start the process.

\o Process( command : String[] ); Same as above, except that \c
command is an array of strings, where the first item is the name of
the program and the following items are command line arguments. This
version is useful if you have arguments that contain spaces or other
characters that would need to be quoted if you just passed a single
string command line, since it takes care of the quoting for you.

\endlist

\section2 Properties

\list

\o arguments : String[]; Contains an array of strings where the first
item is the program to execute and the following items are the
command line arguments.

\o workingDirectory : String; Contains the working directory for the process.

\o running : Boolean; True if the process is currently running;
otherwise false. This property is read-only.

\o exitStatus : Number; Contains the exitStatus of the program when it
has finished. This property is read-only.

\endlist

\section2 Member Functions

\list

\o start( env : String[] ); Tries to run a process for the command and
arguments that were specified with the \c argument property or that
were specified in the constructor. The command is searched for in the
path for executable programs; you can also use an absolute path in the
command itself. If \c env is not specified, the process is
started with the same environment as the starting process. If \c env is
specified, then the values in the \c env stringlist are interpreted as
environment setttings of the form \c VARIABLE=VALUE and the process is
started with these environment settings. If the program could not be
started, an exception is thrown.

\o launch( stdin : String, env : String[] ); Runs the process and
writes the data \c stdin to the process's standard input. If all the
data is written to standard input, standard input is closed. The
command is searched for in the path for executable programs; you can
also use an absolute path in the command itself. If \c env is
unspecified, the process is started with the same environment as
the starting process. If \c env is specified, then the values in the
string list are interpreted as environment setttings of the form \c
VARIABLE=VALUE and the process is started with these environment
settings. If the program could not be started, an exception is thrown.

\o readStdout() : String; Reads what is currently available on the
process's standard output.

\o readSterr() : String; Reads what is currently available on the
process's standard error.

\o canReadLineStdout() : Boolean; Returns true if a line can be read
from the process's standard output.

\o canReadLineStderr() : Boolean; Returns true if a line can be read
from the process's standard error.

\o readLineStdout() : String; Reads one line of text from the
process's standard output if available; otherwise returns an empty
string.

\o readLineStderr() : String; Reads one line of text from the standard
error stream of this process if available; otherwise returns an empty
string.

\o tryTerminate(); Asks the process to terminate. Processes can ignore
this if they wish. If you want to be certain that the process really
terminates, you can use \c kill() instead.

\o kill(); Terminates the process. This is not a safe way to end a
process since the process will not be able to do any
cleanup. \c tryTerminate() is safer, but processes can ignore
\c tryTerminate().

\o writeToStdin( buffer : String ); Writes the data \c buffer to the
standard input stream of this process. The process may or may not read
this data.

\o closeStdin(); Closes the standard input stream of the process

\endlist
