Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Slk.php
public function listWorksheetInfo($pFilename)
    {
        // Open file
        if (!$this->canRead($pFilename)) {
            throw new Exception($pFilename . ' is an Invalid Spreadsheet file.');
        }
        $this->openFile($pFilename);
        $fileHandle = $this->fileHandle;
        rewind($fileHandle);

        $worksheetInfo = [];
        $worksheetInfo[0]['worksheetName'] = 'Worksheet';
        $worksheetInfo[0]['lastColumnLetter'] = 'A';
        $worksheetInfo[0]['lastColumnIndex'] = 0;
        $worksheetInfo[0]['totalRows'] = 0;
        $worksheetInfo[0]['totalColumns'] = 0;

        // loop through one row (line) at a time in the file
        $rowIndex = 0;
        while (($rowData = fgets($fileHandle)) !== false) {
            $columnIndex = 0;

            // convert SYLK encoded $rowData to UTF-8
            $rowData = StringHelper::SYLKtoUTF8($rowData);

            // explode each row at semicolons while taking into account that literal semicolon (;)
            // is escaped like this (;;)
            $rowData = explode("\t", str_replace('¤', ';', str_replace(';', "\t", str_replace(';;', '¤', rtrim($rowData)))));

            $dataType = array_shift($rowData);
            if ($dataType == 'C') {
                //  Read cell value data
                foreach ($rowData as $rowDatum) {
                    switch ($rowDatum[0]) {
                        case 'C':
                        case 'X':
                            $columnIndex = substr($rowDatum, 1) - 1;

                            break;
                        case 'R':
                        case 'Y':
                            $rowIndex = substr($rowDatum, 1);

                            break;
                    }

                    $worksheetInfo[0]['totalRows'] = max($worksheetInfo[0]['totalRows'], $rowIndex);
                    $worksheetInfo[0]['lastColumnIndex'] = max($worksheetInfo[0]['lastColumnIndex'], $columnIndex);
                }
            }
        }

        $worksheetInfo[0]['lastColumnLetter'] = Coordinate::stringFromColumnIndex($worksheetInfo[0]['lastColumnIndex'] + 1);
        $worksheetInfo[0]['totalColumns'] = $worksheetInfo[0]['lastColumnIndex'] + 1;

        // Close file
        fclose($fileHandle);

        return $worksheetInfo;
    }
public function listWorksheetInfo($pFilename)
    {
        // Open file
        if (!$this->canRead($pFilename)) {
            throw new Exception($pFilename . ' is an Invalid Spreadsheet file.');
        }
        $this->openFile($pFilename);
        $fileHandle = $this->fileHandle;
        rewind($fileHandle);

        $worksheetInfo = [];
        $worksheetInfo[0]['worksheetName'] = 'Worksheet';
        $worksheetInfo[0]['lastColumnLetter'] = 'A';
        $worksheetInfo[0]['lastColumnIndex'] = 0;
        $worksheetInfo[0]['totalRows'] = 0;
        $worksheetInfo[0]['totalColumns'] = 0;

        // loop through one row (line) at a time in the file
        $rowIndex = 0;
        while (($rowData = fgets($fileHandle)) !== false) {
            $columnIndex = 0;

            // convert SYLK encoded $rowData to UTF-8
            $rowData = StringHelper::SYLKtoUTF8($rowData);

            // explode each row at semicolons while taking into account that literal semicolon (;)
            // is escaped like this (;;)
            $rowData = explode("\t", str_replace('¤', ';', str_replace(';', "\t", str_replace(';;', '¤', rtrim($rowData)))));

            $dataType = array_shift($rowData);
            if ($dataType == 'C') {
                //  Read cell value data
                foreach ($rowData as $rowDatum) {
                    switch ($rowDatum[0]) {
                        case 'C':
                        case 'X':
                            $columnIndex = substr($rowDatum, 1) - 1;

                            break;
                        case 'R':
                        case 'Y':
                            $rowIndex = substr($rowDatum, 1);

                            break;
                    }

                    $worksheetInfo[0]['totalRows'] = max($worksheetInfo[0]['totalRows'], $rowIndex);
                    $worksheetInfo[0]['lastColumnIndex'] = max($worksheetInfo[0]['lastColumnIndex'], $columnIndex);
                }
            }
        }

        $worksheetInfo[0]['lastColumnLetter'] = Coordinate::stringFromColumnIndex($worksheetInfo[0]['lastColumnIndex'] + 1);
        $worksheetInfo[0]['totalColumns'] = $worksheetInfo[0]['lastColumnIndex'] + 1;

        // Close file
        fclose($fileHandle);

        return $worksheetInfo;
    }
Return worksheet info (Name, Last Column Letter, Last Column Index, Total Rows, Total Columns).

@param string $pFilename

@throws Exception

@return array