Objective-C

Get an FTP Listing Entry's Last-Modified Time

Demonstrates the Chilkat Ftp2.GetLastModifiedTimeStr method, which returns the last-modified time of a cached directory-listing entry as an RFC 822 date-time string. The only argument is a zero-based index.

Background: The last-modified time is the workhorse timestamp: it updates whenever a file's contents change and is what sync and mirror logic compares to decide whether a file needs re-transferring. It is the most reliably reported of the three across FTP servers, and the RFC 822 string carries a timezone so comparisons are well defined.

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Objective-C

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

BOOL success = NO;

//  Demonstrates the Ftp2.GetLastModifiedTimeStr method, which returns the last-modified time of a
//  cached directory-listing entry as an RFC 822 date-time string.  The only argument is a
//  zero-based index.

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;
}

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

//  GetDirCount retrieves the directory listing on the first call and returns the number of
//  entries.  A negative return indicates failure.
int n = [[ftp GetDirCount] intValue];
if (n < 0) {
    NSLog(@"%@",ftp.LastErrorText);
    return;
}

int i;
for (i = 0; i <= n - 1; i++) {
    NSString *name = [ftp GetFilename: [NSNumber numberWithInt: i]];

    //  The value is an RFC 822 string such as "Fri, 21 Nov 1997 09:55:06 -0600".
    NSString *lastModified = [ftp GetLastModifiedTimeStr: [NSNumber numberWithInt: i]];
    NSLog(@"%@%@%@",name,@"  modified ",lastModified);
}

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