\section{Archive formats such as zip}\label{wxarc}
The archive classes handle archive formats such as zip, tar, rar and cab.
-Currently only the wxZip classes are included.
+Currently only the wxZip classes are included. wxTar classes are under
+development at \urlref{wxCode}{http://wxcode.sf.net}.
For each archive type, there are the following classes (using zip here
as an example):
wxFFileOutputStream out(_T("test.zip"));
wxZipOutputStream zip(out);
wxTextOutputStream txt(zip);
+ wxString sep(wxFileName::GetPathSeparator());
zip.PutNextEntry(_T("entry1.txt"));
- txt << _T("Some text for entry1\n");
+ txt << _T("Some text for entry1.txt\n");
- zip.PutNextEntry(_T("entry2.txt"));
- txt << _T("Some text for entry2\n");
+ zip.PutNextEntry(_T("subdir") + sep + _T("entry2.txt"));
+ txt << _T("Some text for subdir/entry2.txt\n");
\end{verbatim}
+The name of each entry can be a full path, which makes it possible to
+store entries in subdirectories.
+
\subsection{Extracting an archive}\label{wxarcextract}
\helpref{Archive formats such as zip}{wxarc}
-\helpref{GetNextEntry()}{wxarchiveinputstreamgetnextentry} returns an
-entry object containing the meta-data for the next entry in the archive
-(and gives away ownership). Reading from the input stream then returns
-the entry's data. Eof() becomes true after an attempt has been made to
-read past the end of the entry's data.
+\helpref{GetNextEntry()}{wxarchiveinputstreamgetnextentry} returns a pointer
+to entry object containing the meta-data for the next entry in the archive
+(and gives away ownership). Reading from the input stream then returns the
+entry's data. Eof() becomes true after an attempt has been made to read past
+the end of the entry's data.
When there are no more entries, GetNextEntry() returns NULL and sets Eof().
\begin{verbatim}
- wxDEFINE_SCOPED_PTR_TYPE(wxZipEntry);
+ // 'smart pointer' type created with wxDEFINE_SCOPED_PTR_TYPE
wxZipEntryPtr entry;
wxFFileInputStream in(_T("test.zip"));
wxZipInputStream zip(in);
- wxTextInputStream txt(zip);
- wxString data;
while (entry.reset(zip.GetNextEntry()), entry.get() != NULL)
{
- wxString name = entry->GetName(); // access meta-data
- txt >> data; // access data
+ // access meta-data
+ wxString name = entry->GetName();
+ // read 'zip' to access the entry's data
}
\end{verbatim}
+The \helpref{smart pointer}{wxscopedptr} type {\em wxZipEntryPtr}
+can be created like this:
+
+\begin{verbatim}
+ #include <wx/ptr_scpd.h>
+ wxDEFINE_SCOPED_PTR_TYPE(wxZipEntry);
+
+\end{verbatim}
+
\subsection{Modifying an archive}\label{wxarcmodify}
since it will copy them without decompressing and recompressing them.
In general modifications are not possible without rewriting the archive,
-though it may be possible in some limited cases. Even then, rewriting
-the archive is usually a better choice since a failure can be handled
-without losing the whole archive.
+though it may be possible in some limited cases. Even then, rewriting the
+archive is usually a better choice since a failure can be handled without
+losing the whole
+archive. \helpref{wxTempFileOutputStream}{wxtempfileoutputstream} can
+be helpful to do this.
For example to delete all entries matching the pattern "*.txt":
\begin{verbatim}
- wxFFileInputStream in(_T("in.zip"));
- wxFFileOutputStream out(_T("out.zip"));
+ wxFFileInputStreamPtr in(new wxFFileInputStream(_T("test.zip")));
+ wxTempFileOutputStream out(_T("test.zip"));
- wxZipInputStream inzip(in);
+ wxZipInputStream inzip(*in);
wxZipOutputStream outzip(out);
+
+ // 'smart pointer' type created with wxDEFINE_SCOPED_PTR_TYPE
wxZipEntryPtr entry;
// transfer any meta-data for the archive as a whole (the zip comment
if (!outzip.CopyEntry(entry.release(), inzip))
break;
- bool success = inzip.Eof() && outzip.Close();
+ // close the input stream by releasing the pointer to it, do this
+ // before closing the output stream so that the file can be replaced
+ in.reset();
+
+ // you can check for success as follows
+ bool success = inzip.Eof() && outzip.Close() && out.Commit();
+
+\end{verbatim}
+
+The \helpref{smart pointer}{wxscopedptr} types {\em wxZipEntryPtr}
+and {\em wxFFileInputStreamPtr} can be created like this:
+
+\begin{verbatim}
+ #include <wx/ptr_scpd.h>
+ wxDEFINE_SCOPED_PTR_TYPE(wxZipEntry);
+ wxDEFINE_SCOPED_PTR_TYPE(wxFFileInputStream);
\end{verbatim}
and search for that:
\begin{verbatim}
- wxDEFINE_SCOPED_PTR_TYPE(wxZipEntry);
+ // 'smart pointer' type created with wxDEFINE_SCOPED_PTR_TYPE
wxZipEntryPtr entry;
// convert the local name we are looking for into the internal format
\helpref{wxArchiveClassFactory}{wxarchiveclassfactory}, which can create
the other classes.
-For example, given {\it wxArchiveClassFactory* factory}:
+For example, given {\it wxArchiveClassFactory* factory}, streams and
+entries can be created like this:
\begin{verbatim}
// create streams without knowing their type
\end{verbatim}
+The \helpref{smart pointer}{wxscopedptr} types {\em wxArchiveInputStreamPtr},
+{\em wxArchiveOutputStreamPtr} and {\em wxArchiveEntryPtr} would need to
+have already have been defined, which could be done like this:
+
+\begin{verbatim}
+ #include <wx/ptr_scpd.h>
+ wxDEFINE_SCOPED_PTR_TYPE(wxArchiveInputStream);
+ wxDEFINE_SCOPED_PTR_TYPE(wxArchiveOutputStream);
+ wxDEFINE_SCOPED_PTR_TYPE(wxArchiveEntry);
+
+\end{verbatim}
+
The class factory itself can either be created explicitly:
\begin{verbatim}
projects / wxWidgets.git / blobdiff