Perl

Read Text at a String Offset from a Remote SFTP File

Demonstrates the Chilkat SFtp.ReadFileText64s method, which is like ReadFileText64 but takes the byte offset as a decimal string. The arguments are the handle, the offset string, the maximum number of bytes, and the charset.

Background: The string-offset read exists for the same reason as its write counterpart: it lets code in languages without convenient 64-bit integers still address positions in very large files by supplying the offset as text. Functionally it is identical to the int64 version.

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Perl

use chilkat();

$success = 0;

#  Demonstrates the SFtp.ReadFileText64s method, which is like ReadFileText64 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 maximum number of bytes, and the 4th is the charset.

$sftp = chilkat::CkSFtp->new();

#  Connect, authenticate, and initialize the SFTP subsystem.
$port = 22;
$success = $sftp->Connect("sftp.example.com",$port);
if ($success == 0) {
    print $sftp->lastErrorText() . "\r\n";
    exit;
}

#  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.
$password = "mySshPassword";

$success = $sftp->AuthenticatePw("mySshLogin",$password);
if ($success == 0) {
    print $sftp->lastErrorText() . "\r\n";
    exit;
}

$success = $sftp->InitializeSftp();
if ($success == 0) {
    print $sftp->lastErrorText() . "\r\n";
    exit;
}

$handle = $sftp->openFile("subdir/hugefile.dat","readOnly","openExisting");
if ($sftp->get_LastMethodSuccess() == 0) {
    print $sftp->lastErrorText() . "\r\n";
    exit;
}

#  Supplying the offset as a string is convenient in languages without a native 64-bit integer.
$offset = "5000000000";
$numBytes = 6;
$text = $sftp->readFileText64s($handle,$offset,$numBytes,"utf-8");
if ($sftp->get_LastMethodSuccess() == 0) {
    print $sftp->lastErrorText() . "\r\n";
    exit;
}

print $text . "\r\n";

$success = $sftp->CloseHandle($handle);
if ($success == 0) {
    print $sftp->lastErrorText() . "\r\n";
    exit;
}

$sftp->Disconnect();