(Perl) Azure Blob - Get Tags (Check if Blob Exists)

See more Azure Cloud Storage Examples

Gets the user-defined tags for a specified blob. This can also be used as a way to check to see if a blob exists.

For more information, see https://learn.microsoft.com/en-us/rest/api/storageservices/get-blob-tags

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

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

$rest = chilkat::CkRest->new();

# Connect to the Azure Storage Blob Service
$bTls = 1;
$port = 443;
$bAutoReconnect = 1;
# In this example, the storage account name is "chilkat".
$success = $rest->Connect("chilkat.blob.core.windows.net",$port,$bTls,$bAutoReconnect);
if ($success != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# Provide Azure Cloud credentials for the REST call.
$azAuth = chilkat::CkAuthAzureStorage->new();
$azAuth->put_AccessKey("AZURE_ACCESS_KEY");
# The account name used here should match the 1st part of the domain passed in the call to Connect (above).
$azAuth->put_Account("chilkat");
$azAuth->put_Scheme("SharedKey");
$azAuth->put_Service("Blob");
# This causes the "x-ms-version: 2021-08-06" header to be automatically added.
$azAuth->put_XMsVersion("2021-08-06");
$success = $rest->SetAuthAzureStorage($azAuth);

# Note: The application does not need to explicitly set the following
# headers: Content-Length, x-ms-date, Authorization.  These headers
# are automatically set by Chilkat.

# The Azure blob container is "test", the file is "helloWorld.txt"
# Add "?comp=tags" to get the user-defined tags instead of the actual blob content.
$sb = chilkat::CkStringBuilder->new();
$success = $rest->FullRequestNoBodySb("GET","/test/helloWorldajdfadf.txt?comp=tags",$sb);
if ($success == 0) {
    # Examine the request/response to see what happened.
    print "response status code = " . $rest->get_ResponseStatusCode() . "\r\n";
    print "response status text = " . $rest->responseStatusText() . "\r\n";
    print "response header: " . $rest->responseHeader() . "\r\n";
    print "---" . "\r\n";
    print "LastRequestStartLine: " . $rest->lastRequestStartLine() . "\r\n";
    print "LastRequestHeader: " . $rest->lastRequestHeader() . "\r\n";
    exit;
}

# A typical blob with no tags will return this:

# <?xml version="1.0" encoding="utf-8"?>
# <Tags><TagSet/></Tags>

# If the blob does not exist, you get this:

# <?xml version="1.0" encoding="utf-8"?>
# <Error>
#     <Code>BlobNotFound</Code>
#     <Message>The specified blob does not exist.
# 	RequestId:fcfefdd9-301e-001a-2135-3a23d2000000
# 	Time:2023-02-06T14:17:00.7805577Z
#     </Message>
# </Error>

print $sb->getAsString() . "\r\n";

# To see if we got Tags or an Error, then examine the XML.
$xml = chilkat::CkXml->new();
$xml->LoadSb($sb,1);

# Examine the tag..
if ($xml->TagEquals("Tags") == 1) {
    print "Blob exists!" . "\r\n";
}
else {

    if ($xml->ChildContentMatches("Code","BlobNotFound",1) == 1) {
        print "Blob does not exist." . "\r\n";
    }
    else {
        print "Some other error..." . "\r\n";
    }

}

print "Success." . "\r\n";