fprintf - PHP code example

The PHP Function Fprintf

The php function fprintf writes a formatted string to a stream, like a file or database. It takes a format string and then any number of arguments, which are spliced into the appropriate places in the format string to generate the output. The function also returns the length of the string written.

The list of possible format strings is long and varied. You can use them to print binary numbers, easily output scientific notations (for example, '%E+') and more. You can find the full list in the PHP Manual sprintf page.

In addition to the standard formats, there are some special formats that are used to do other things, such as padding the value with a specific character or pad it with zeros. You can also add a width> to pad the value out to a certain width, which is useful when you want to ensure that all of the arguments fit in a fixed number of characters, for example, to avoid wrapping if you're printing an integer over several lines.

Other functions in the fprintf family are used to do other kinds of textual manipulations, such as escaping special characters or adding a trailing comma at the end of the list of parameters to a function. Other examples are rtrim(), which removes white space from the right side of a string, and quotemeta(), which puts backslashes before any non-alphanumeric characters in a string to prevent them from being considered as literals.

fprintf example

/** * Create a new InputStream wrapper. * * @param string $data Data to parse. * @param string $encoding The encoding to use for the data. * @param string $debug A fprintf format to use to echo the data on stdout. */
    public function __construct($data, $encoding = 'UTF-8', $debug = '')
    {
        $data = UTF8Utils::convertToUTF8($data, $encoding);
        if ($debug) {
            fprintf(STDOUT, $debug, $data, strlen($data));
        }

        // There is good reason to question whether it makes sense to         // do this here, since most of these checks are done during         // parsing, and since this check doesn't actually *do* anything.         $this->errors = UTF8Utils::checkForIllegalCodepoints($data);

        $data = $this->replaceLinefeeds($data);

        $this->data = $data;
        $this->char = 0;

    /** * Writes an "integer" node. * * @param resource $file The file handle to write to * * @see http://source.icu-project.org/repos/icu/icuhtml/trunk/design/bnf_rb.txt */
    private function writeInteger($file, int $value): void
    {
        fprintf($file, ':int{%d}', $value);
    }

    /** * Writes an "intvector" node. * * @param resource $file The file handle to write to * * @see http://source.icu-project.org/repos/icu/icuhtml/trunk/design/bnf_rb.txt */
    private function writeIntVector($file, array $value, int $indentation): void
    {

else {
            return self::$yy_action[$i];
        }
    }

    function yy_shift($yyNewState, $yyMajor, $yypMinor)
    {
        $this->yyidx++;
        if ($this->yyidx >= self::YYSTACKDEPTH) {
            $this->yyidx--;
            if (self::$yyTraceFILE) {
                fprintf(self::$yyTraceFILE, "%sStack Overflow!\n", self::$yyTracePrompt);
            }
            while ($this->yyidx >= 0) {
                $this->yy_pop_parser_stack();
            }
#line 125 "smarty_internal_configfileparser.y"
    $this->internalError = true;
    $this->compiler->trigger_config_file_error("Stack overflow in configfile parser");
#line 593 "smarty_internal_configfileparser.php"             return;
        }

else {
            return self::$yy_action[$i];
        }
    }

    function yy_shift($yyNewState, $yyMajor, $yypMinor)
    {
        $this->yyidx++;
        if ($this->yyidx >= self::YYSTACKDEPTH) {
            $this->yyidx--;
            if (self::$yyTraceFILE) {
                fprintf(self::$yyTraceFILE, "%sStack Overflow!\n", self::$yyTracePrompt);
            }
            while ($this->yyidx >= 0) {
                $this->yy_pop_parser_stack();
            }
#line 84 "smarty_internal_templateparser.y"
    $this->internalError = true;
    $this->compiler->trigger_template_error("Stack overflow in template parser");
#line 1724 "smarty_internal_templateparser.php"             return;
        }

\STREAM_NOTIFY_FAILURE => 'FAILURE',
            \STREAM_NOTIFY_COMPLETED => 'COMPLETED',
            \STREAM_NOTIFY_RESOLVE => 'RESOLVE',
        ];
        static $args = ['severity', 'message', 'message_code', 'bytes_transferred', 'bytes_max'];

        $value = Utils::debugResource($value);
        $ident = $request->getMethod().' '.$request->getUri()->withFragment('');
        self::addNotification(
            $params,
            static function Dint $code, ...$passed) use ($ident, $value, $map, $args): void {
                \fprintf($value, '<%s> [%s] ', $ident, $map[$code]);
                foreach (\array_filter($passed) as $i => $v) {
                    \fwrite($value, $args[$i].': "'.$v.'" ');
                }
                \fwrite($value, "\n");
            }
        );
    }

    private static function addNotification(array &$params, callable $notify): void
    {
        // Wrap the existing function if needed.