passthru(3) [php man page]

PASSTHRU(3)								 1							       PASSTHRU(3)

passthru - Execute an external program and display raw output

SYNOPSIS

       void passthru (string  $command, [int  &$return_var])

DESCRIPTION

	The  passthru(3)  function  is	similar  to  the exec(3) function in that it executes a $command. This function should be used in place of
       exec(3) or system(3) when the output from the Unix command is binary data which needs to be passed directly back to the browser.  A  common
       use  for  this  is to execute something like the pbmplus utilities that can output an image stream directly. By setting the Content-type to
       image/gif and then calling a pbmplus program to output a gif, you can create PHP scripts that output images directly.

PARAMETERS

	      o $command
		- The command that will be executed.

	      o $return_var
		- If the $return_var argument is present, the return status of the Unix command will be placed here.

RETURN VALUES

	No value is returned.

NOTES

       Warning

	      When allowing user-supplied data to be passed to this function, use escapeshellarg(3) or escapeshellcmd(3) to ensure that users can-
	      not trick the system into executing arbitrary commands.

       Note

	      If a program is started with this function, in order for it to continue running in the background, the output of the program must be
	      redirected to a file or another output stream. Failing to do so will cause PHP to hang until the execution of the program ends.

       Note

	      When safe mode is enabled, you can only execute files within the safe_mode_exec_dir. For practical  reasons,  it	is  currently  not
	      allowed to have .. components in the path to the executable.

       Warning

	      With safe mode enabled, the command string is escaped with escapeshellcmd(3). Thus, echo y | echo x becomes echo y | echo x.

SEE ALSO

       exec(3), system(3), popen(3), escapeshellcmd(3), backtick operator.

PHP Documentation Group 													       PASSTHRU(3)

IMAGEGIF(3)								 1							       IMAGEGIF(3)

imagegif - Output image to browser or file

SYNOPSIS

       bool imagegif (resource	$image, [string  $filename])

DESCRIPTION

       imagegif(3)  creates the GIF file in filename from the image $image. The $image argument is the return from the imagecreate(3) or imagecre-
       atefrom* function.

	The image format will be GIF87a unless the image has been made transparent with imagecolortransparent(3), in which case the  image  format
       will be GIF89a.

PARAMETERS

	      o $
		image -An image resource, returned by one of the image creation functions, such as imagecreatetruecolor(3).

	      o $filename
		-The path to save the file to. If not set or NULL, the raw image stream will be outputted directly.

RETURN VALUES

	Returns TRUE on success or FALSE on failure.

EXAMPLES

       Example #1

	      Outputting an image using imagegif(3)

	      <?php
	      // Create a new image instance
	      $im = imagecreatetruecolor(100, 100);

	      // Make the background white
	      imagefilledrectangle($im, 0, 0, 99, 99, 0xFFFFFF);

	      // Draw a text string on the image
	      imagestring($im, 3, 40, 20, 'GD Library', 0xFFBA00);

	      // Output the image to browser
	      header('Content-Type: image/gif');

	      imagegif($im);
	      imagedestroy($im);
	      ?>

       Example #2

	      Converting a PNG image to GIF using imagegif(3)

	      <?php

	      // Load the PNG
	      $png = imagecreatefrompng('./php.png');

	      // Save the image as a GIF
	      imagegif($png, './php.gif');

	      // Free from memory
	      imagedestroy($png);

	      // We're done
	      echo 'Converted PNG image to GIF with success!';
	      ?>

NOTES

       Note

	      GIF support was removed from the GD library in Version 1.6, and added back in Version 2.0.28. This function is not available between
	      these versions. For more information, see the GD Project site.

	       The following code snippet allows you to write more portable PHP applications by auto-detecting the type of  GD	support  which	is
	      available. Replace the sequence header ("Content-Type: image/gif"); imagegif ($im); by the more flexible sequence:

	      <?php
	      // Create a new image instance
	      $im = imagecreatetruecolor(100, 100);

	      // Do some image operations here

	      // Handle output
	      if(function_exists('imagegif'))
	      {
		  // For GIF
		  header('Content-Type: image/gif');

		  imagegif($im);
	      }
	      elseif(function_exists('imagejpeg'))
	      {
		  // For JPEG
		  header('Content-Type: image/jpeg');

		  imagejpeg($im, NULL, 100);
	      }
	      elseif(function_exists('imagepng'))
	      {
		  // For PNG
		  header('Content-Type: image/png');

		  imagepng($im);
	      }
	      elseif(function_exists('imagewbmp'))
	      {
		  // For WBMP
		  header('Content-Type: image/vnd.wap.wbmp');

		  imagewbmp($im);
	      }
	      else
	      {
		  imagedestroy($im);

		  die('No image support in this PHP server');
	      }

	      // If image support was found for one of these
	      // formats, then free it from memory
	      if($im)
	      {
		  imagedestroy($im);
	      }
	      ?>

       Note

	       As of PHP 4.0.2 you can use the function imagetypes(3) in place of function_exists(3) for checking the presence of the various sup-
	      ported image formats:

	      <?php
	      if(imagetypes() & IMG_GIF)
	      {
		  header('Content-Type: image/gif');
		  imagegif($im);
	      }
	      elseif(imagetypes() & IMG_JPG)
	      {
		  /* ... etc. */
	      }
	      ?>

SEE ALSO

       imagepng(3), imagewbmp(3), imagejpeg(3), imagetypes(3).

PHP Documentation Group 													       IMAGEGIF(3)