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wxTextFile

The wxTextFile is a simple class which allows to work with text files on line by line basis. It also understands the differences in line termination characters under different platforms and will not do anything bad to files with "non native" line termination sequences - in fact, it can be also used to modify the text files and change the line termination characters from one type (say DOS) to another (say Unix).

One word of warning: the class is not at all optimized for big files and so it will load the file entirely into memory when opened. Of course, you should not work in this way with large files (as an estimation, anything over 1 Megabyte is surely too big for this class). On the other hand, it is not a serious limitation for the small files like configuration files or programs sources which are well handled by wxTextFile.

The typical things you may do with wxTextFile in order are:

Derived from

No base class

Include files

<wx/textfile.h>

Data structures

The following constants identify the line termination type:

enum wxTextFileType
{
    wxTextFileType_None,  // incomplete (the last line of the file only)
    wxTextFileType_Unix,  // line is terminated with 'LF' = 0xA = 10 = '\n'
    wxTextFileType_Dos,   //                         'CR' 'LF'
    wxTextFileType_Mac    //                         'CR' = 0xD = 13 = '\r'
};
See also

wxFile

Members

wxTextFile::wxTextFile
wxTextFile::wxTextFile
wxTextFile::Exists
wxTextFile::Open
wxTextFile::Open
wxTextFile::Close
wxTextFile::IsOpened
wxTextFile::GetLineCount
wxTextFile::GetLine
wxTextFile::operator[]
wxTextFile::GetCurrentLine
wxTextFile::GoToLine
wxTextFile::Eof
wxTextFile::GetFirstLine
wxTextFile::GetNextLine
wxTextFile::GetPrevLine
wxTextFile::GetLastLine
wxTextFile::GetLineType
wxTextFile::GuessType
wxTextFile::GetName
wxTextFile::AddLine
wxTextFile::InsertLine
wxTextFile::RemoveLine
wxTextFile::Write
wxTextFile::GetEOL
wxTextFile::~wxTextFile


wxTextFile::wxTextFile

wxTextFile() const

Default constructor, use Open(string) to initialize the object.


wxTextFile::wxTextFile

wxTextFile(const wxString& strFile) const

Constructor does not load the file into memory, use Open() to do it.


wxTextFile::Exists

bool Exists() const

Return TRUE if file exists - the name of the file should have been specified in the constructor before calling Exists().


wxTextFile::Open

bool Open() const

Open() opens the file with the name which was given in the constructor and also loads file in memory on success.


wxTextFile::Open

bool Open(const wxString& strFile) const

Same as Open() but allows to specify the file name (must be used if the default constructor was used to create the object).


wxTextFile::Close

bool Close() const

Closes the file and frees memory, losing all changes. Use Write() if you want to save them.


wxTextFile::IsOpened

bool IsOpened() const

Returns TRUE if the file is currently opened.


wxTextFile::GetLineCount

size_t GetLineCount() const

Get the number of lines in the file.


wxTextFile::GetLine

wxString& GetLine(size_t n) const

Retrieves the line number n from the file. The returned line may be modified but you shouldn't add line terminator at the end - this will be done by wxTextFile.


wxTextFile::operator[]

wxString& operator[](size_t n) const

The same as GetLine.


wxTextFile::GetCurrentLine

size_t GetCurrentLine() const

Returns the current line: it has meaning only when you're using GetFirstLine()/GetNextLine() functions, it doesn't get updated when you're using "direct access" functions like GetLine(). GetFirstLine() and GetLastLine() also change the value of the current line, as well as GoToLine().


wxTextFile::GoToLine

void GoToLine(size_t n) const

Changes the value returned by GetCurrentLine and used by GetFirstLine()/GetNextLine().


wxTextFile::Eof

bool Eof() const

Returns TRUE if the current line is the last one.


wxTextFile::GetFirstLine

wxString& GetFirstLine() const

This method together with GetNextLine() allows more "iterator-like" traversal of the list of lines, i.e. you may write something like:

for ( str = GetFirstLine(); !Eof(); str = GetNextLine() )
{
    // do something with the current line in str
}

wxTextFile::GetNextLine

wxString& GetNextLine()

Gets the next line (see GetFirstLine for the example).


wxTextFile::GetPrevLine

wxString& GetPrevLine()

Gets the previous line in the file.


wxTextFile::GetLastLine

wxString& GetLastLine()

Gets the last line of the file.


wxTextFile::GetLineType

wxTextFileType GetLineType(size_t n) const

Get the type of the line (see also GetEOL)


wxTextFile::GuessType

wxTextFileType GuessType() const

Guess the type of file (which is supposed to be opened). If sufficiently many lines of the file are in DOS/Unix/Mac format, the corresponding value will be returned. If the detection mechanism fails wxTextFileType_None is returned.


wxTextFile::GetName

const char* GetName() const

Get the name of the file.


wxTextFile::AddLine

void AddLine(const wxString& str, wxTextFileType type = typeDefault) const

Adds a line to the end of file.


wxTextFile::InsertLine

void InsertLine(const wxString& str, size_t n, wxTextFileType type = typeDefault) const

Insert a line before the line number n.


wxTextFile::RemoveLine

void RemoveLine(size_t n) const

Delete line number n from the file.


wxTextFile::Write

bool Write(wxTextFileType typeNew = wxTextFileType_None) const

Change the file on disk. The typeNew parameter allows you to change the file format (default argument means "don't change type") and may be used to convert, for example, DOS files to Unix.

Returns TRUE if operation succeeded, FALSE if it failed.


wxTextFile::GetEOL

static const char* GetEOL(wxTextFileType type = typeDefault) const

Get the line termination string corresponding to given constant. typeDefault is the value defined during the compilation and corresponds to the native format of the platform, i.e. it will be wxTextFileType_Dos under Windows, wxTextFileType_Unix under Unix and wxTextFileType_Mac under Mac.


wxTextFile::~wxTextFile

~wxTextFile() const

Destructor does nothing.