Objective-C

Monitor FTP Transfer Progress

Demonstrates the progress properties CurBytesReceived, CurBytesReceivedStr, CurBytesSent, CurBytesSentStr, ProgressMonSize, PercentDoneScale, and AutoGetSizeForProgress.

Note: The local paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: Percentage progress needs a known total, but FTP does not always report a file's size up front — so AutoGetSizeForProgress issues a SIZE command before a download, and ProgressMonSize supplies an expected size when even that is unavailable (a one-shot value consumed by the next transfer). PercentDoneScale sets the resolution of progress callbacks. The current byte counts are exposed both as 32-bit integers and as strings, the string forms avoiding integer-width limits for very large transfers.

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Objective-C

#import <CkoFtp2.h>

BOOL success = NO;

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

ftp.Hostname = @"ftp.example.com";
ftp.Username = @"myFtpLogin";

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
ftp.Password = @"myPassword";

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

//  AutoGetSizeForProgress sends a SIZE command before a download so percentage-based progress can
//  be computed.
ftp.AutoGetSizeForProgress = YES;

//  PercentDoneScale sets the value representing one hundred percent in PercentDone callbacks.
//  1000 gives tenth-of-a-percent resolution.
ftp.PercentDoneScale = [NSNumber numberWithInt:1000];

//  ProgressMonSize is a one-shot expected size for the next download when the size is not
//  otherwise known.  It is consumed by the next download and reset to 0.
ftp.ProgressMonSize = [NSNumber numberWithInt:20485760];

success = [ftp GetFile: @"public_html/bigfile.zip" localPath: @"qa_output/bigfile.zip"];
if (success == NO) {
    NSLog(@"%@",ftp.LastErrorText);
    return;
}

//  After a transfer, the current byte counts are available as 32-bit numbers or as strings (the
//  string forms avoid integer-size limits).
NSLog(@"%@%d",@"Bytes received: ",ftp.CurBytesReceived);
NSLog(@"%@%@",@"Bytes received (str): ",ftp.CurBytesReceivedStr);
NSLog(@"%@%d",@"Bytes sent: ",ftp.CurBytesSent);
NSLog(@"%@%@",@"Bytes sent (str): ",ftp.CurBytesSentStr);

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