(Objective-C) Unzip a Text File Entry into a StringBuilder Using ZipEntry.UnzipToSb

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This example demonstrates how to use the ZipEntry.UnzipToSb method to inflate a text file entry directly into a StringBuilder object.

The ZIP entry is uncompressed entirely in memory and appended to the StringBuilder without creating a temporary file on disk.

This is useful when:

• Processing text files directly in memory
• Avoiding temporary filesystem files
• Reading configuration files, JSON, XML, CSV, or source code from ZIP archives
• Automatically converting line endings while inflating the text

The srcCharset argument specifies how the uncompressed bytes should be interpreted, such as:

• utf-8
• utf-16
• windows-1252

The lineEndingBehavior argument controls line-ending conversion:

• 0 — Leave line endings unchanged
• 1 — Convert all line endings to bare LF
• 2 — Convert all line endings to CRLF

Suppose the ZIP archive contains:

config/settings.json

The example inflates the JSON file directly into a StringBuilder.

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#import <CkoZip.h>
#import <CkoZipEntry.h>
#import <CkoStringBuilder.h>
#import <NSString.h>

BOOL success = NO;

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

// Open an existing ZIP archive.
success = [zip OpenZip: @"qa_data/zips/configFiles.zip"];
if (success == NO) {
    NSLog(@"%@",zip.LastErrorText);
    return;
}

// Locate the JSON file entry within the ZIP archive.
CkoZipEntry *entry = [[CkoZipEntry alloc] init];

success = [zip EntryOf: @"config/settings.json" entry: entry];
if (success == NO) {
    NSLog(@"%@",@"ZIP entry not found.");
    [zip CloseZip];
    return;
}

// ------------------------------------------------------------
// Inflate the ZIP entry directly into a StringBuilder.
// 
// The uncompressed text is appended to the StringBuilder.
// 
CkoStringBuilder *sb = [[CkoStringBuilder alloc] init];

// Leave line endings unchanged.
int lineEndingBehavior = 0;

// Interpret the uncompressed bytes as UTF-8 text.
NSString *srcCharset = @"utf-8";

success = [entry UnzipToSb: [NSNumber numberWithInt: lineEndingBehavior] srcCharset: srcCharset sb: sb];
if (success == NO) {
    NSLog(@"%@",entry.LastErrorText);
    return;
}

NSLog(@"%@",@"Uncompressed text:");
NSLog(@"%@",@"");
NSLog(@"%@",[sb GetAsString]);

[zip CloseZip];

NSLog(@"%@",@"Done.");