(Lianja) Remove an Entry from an Existing ZIP Using DeleteEntry

This example demonstrates how to use the DeleteEntry method to remove a file from an existing ZIP archive.

The example:

• Creates a ZIP archive containing three text files
• Opens the ZIP archive for modification
• Finds and deletes one entry
• Writes the modified ZIP archive to a new filename

Suppose the original ZIP archive contains:

a.txt
b.txt
c.txt

After deleting b.txt, the modified ZIP archive contains:

a.txt
c.txt

The entry is removed only from the in-memory ZIP object until a Write* method is called.

Note: This example requires Chilkat v11.0.0 or greater.

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llSuccess = .F.

llSuccess = .F.

// ------------------------------------------------------------
// First create a ZIP archive containing three text files.

loZip = createobject("CkZip")

llSuccess = loZip.NewZip("original.zip")
if (llSuccess = .F.) then
    ? loZip.LastErrorText
    release loZip
    return
endif

lcCharset = "utf-8"

llSuccess = loZip.AddString("a.txt","Contents of file A",lcCharset)
if (llSuccess = .F.) then
    ? loZip.LastErrorText
    release loZip
    return
endif

llSuccess = loZip.AddString("b.txt","Contents of file B",lcCharset)
if (llSuccess = .F.) then
    ? loZip.LastErrorText
    release loZip
    return
endif

llSuccess = loZip.AddString("c.txt","Contents of file C",lcCharset)
if (llSuccess = .F.) then
    ? loZip.LastErrorText
    release loZip
    return
endif

// Write the ZIP archive to disk.
// 
// The ZIP now contains:
// 
//     a.txt
//     b.txt
//     c.txt
// 
llSuccess = loZip.WriteZipAndClose()
if (llSuccess = .F.) then
    ? loZip.LastErrorText
    release loZip
    return
endif

// ------------------------------------------------------------
// Open the existing ZIP archive for modification.

loZip2 = createobject("CkZip")

llSuccess = loZip2.OpenZip("original.zip")
if (llSuccess = .F.) then
    ? loZip2.LastErrorText
    release loZip
    release loZip2
    return
endif

// Find the entry named "b.txt".
loEntry = createobject("CkZipEntry")

llSuccess = loZip2.EntryOf("b.txt",loEntry)
if (llSuccess = .F.) then
    ? loZip2.LastErrorText
    release loZip
    release loZip2
    release loEntry
    return
endif

// Remove the entry from the in-memory ZIP object.
// 
// At this point, the original ZIP file on disk is unchanged.
// The deletion takes effect only after WriteZip or
// WriteZipAndClose is called.
llSuccess = loZip2.DeleteEntry(loEntry)
if (llSuccess = .F.) then
    ? loZip2.LastErrorText
    release loZip
    release loZip2
    release loEntry
    return
endif

// Write the modified ZIP archive to a new file.
loZip2.FileName = "modified.zip"

llSuccess = loZip2.WriteZipAndClose()
if (llSuccess = .F.) then
    ? loZip2.LastErrorText
    release loZip
    release loZip2
    release loEntry
    return
endif

// The modified ZIP now contains:
// 
//     a.txt
//     c.txt
// 

? "ZIP archive updated successfully."


release loZip
release loZip2
release loEntry