(Objective-C) Restart/Resume FTP Download

Resume downloading a file from an FTP server.

Chilkat Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoFtp2.h>
#import <NSString.h>

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

CkoFtp2 *ftp = [[CkoFtp2 alloc] init];

ftp.Hostname = @"ftp.example.com";
ftp.Username = @"login";
ftp.Password = @"password";

// Connect and login to the FTP server.
BOOL success = [ftp Connect];
if (success != YES) {
    NSLog(@"%@",ftp.LastErrorText);
    return;
}

// Change to the remote directory where the file is located.
// This step is only necessary if the file is not in the root directory
// for the FTP account.
success = [ftp ChangeRemoteDir: @"temp"];
if (success != YES) {
    NSLog(@"%@",ftp.LastErrorText);
    return;
}

// To resume a download, it is assumed that the partial file
// is already present on the local filesystem.
// You only need to set the RestartNext property to resume
// the download.  The Chilkat FTP component sets the resume
// point by getting the existing size of the target (local) file.
ftp.RestartNext = YES;

NSString *localFilename = @"big.zip";
NSString *remoteFilename = @"big.zip";

// Resume downloading...
success = [ftp GetFile: remoteFilename localPath: localFilename];
if (success != YES) {
    NSLog(@"%@",ftp.LastErrorText);
    return;
}

success = [ftp Disconnect];

NSLog(@"%@",@"File Downloaded!");