Objective-C

Write Text at a String Offset in a Remote SFTP File

Demonstrates the Chilkat SFtp.WriteFileText64s method, which is like WriteFileText64 but takes the byte offset as a decimal string. The arguments are the handle, the offset string, the charset, and the text.

Background: Some programming languages Chilkat targets lack a native 64-bit integer type, or make large integer literals awkward. Passing the offset as a decimal string sidesteps that entirely — the value is parsed by the library — while addressing the same large-file positions as the int64 form.

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Objective-C

#import <CkoSFtp.h>
#import <NSString.h>

BOOL success = NO;

//  Demonstrates the SFtp.WriteFileText64s method, which is like WriteFileText64 but takes the
//  byte offset as a decimal string.  The 1st argument is the handle, the 2nd is the offset string,
//  the 3rd is the charset, and the 4th is the text.

CkoSFtp *sftp = [[CkoSFtp alloc] init];

//  Connect, authenticate, and initialize the SFTP subsystem.
int port = 22;
success = [sftp Connect: @"sftp.example.com" port: [NSNumber numberWithInt: port]];
if (success == NO) {
    NSLog(@"%@",sftp.LastErrorText);
    return;
}

//  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.
NSString *password = @"mySshPassword";

success = [sftp AuthenticatePw: @"mySshLogin" password: password];
if (success == NO) {
    NSLog(@"%@",sftp.LastErrorText);
    return;
}

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

NSString *handle = [sftp OpenFile: @"subdir/hugefile.dat" access: @"readWrite" createDisp: @"openOrCreate"];
if (sftp.LastMethodSuccess == NO) {
    NSLog(@"%@",sftp.LastErrorText);
    return;
}

//  Supplying the offset as a string is convenient in languages without a native 64-bit integer.
NSString *offset = @"5000000000";
success = [sftp WriteFileText64s: handle offset64: offset charset: @"utf-8" textData: @"MARKER"];
if (success == NO) {
    NSLog(@"%@",sftp.LastErrorText);
    return;
}

success = [sftp CloseHandle: handle];
if (success == NO) {
    NSLog(@"%@",sftp.LastErrorText);
    return;
}

NSLog(@"%@",@"Wrote at the string offset.");

[sftp Disconnect];