(Objective-C) 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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#import <CkoZip.h>
#import <NSString.h>
#import <CkoZipEntry.h>

BOOL success = NO;

success = NO;

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

CkoZip *zip = [[CkoZip alloc] init];

success = [zip NewZip: @"original.zip"];
if (success == NO) {
    NSLog(@"%@",zip.LastErrorText);
    return;
}

NSString *charset = @"utf-8";

success = [zip AddString: @"a.txt" content: @"Contents of file A" charset: charset];
if (success == NO) {
    NSLog(@"%@",zip.LastErrorText);
    return;
}

success = [zip AddString: @"b.txt" content: @"Contents of file B" charset: charset];
if (success == NO) {
    NSLog(@"%@",zip.LastErrorText);
    return;
}

success = [zip AddString: @"c.txt" content: @"Contents of file C" charset: charset];
if (success == NO) {
    NSLog(@"%@",zip.LastErrorText);
    return;
}

// Write the ZIP archive to disk.
// 
// The ZIP now contains:
// 
//     a.txt
//     b.txt
//     c.txt
// 
success = [zip WriteZipAndClose];
if (success == NO) {
    NSLog(@"%@",zip.LastErrorText);
    return;
}

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

CkoZip *zip2 = [[CkoZip alloc] init];

success = [zip2 OpenZip: @"original.zip"];
if (success == NO) {
    NSLog(@"%@",zip2.LastErrorText);
    return;
}

// Find the entry named "b.txt".
CkoZipEntry *entry = [[CkoZipEntry alloc] init];

success = [zip2 EntryOf: @"b.txt" entry: entry];
if (success == NO) {
    NSLog(@"%@",zip2.LastErrorText);
    return;
}

// 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.
success = [zip2 DeleteEntry: entry];
if (success == NO) {
    NSLog(@"%@",zip2.LastErrorText);
    return;
}

// Write the modified ZIP archive to a new file.
zip2.FileName = @"modified.zip";

success = [zip2 WriteZipAndClose];
if (success == NO) {
    NSLog(@"%@",zip2.LastErrorText);
    return;
}

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

NSLog(@"%@",@"ZIP archive updated successfully.");