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This article brings you a summary of image processing and file operation methods in PHP (with code). It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.
Part One: Image Processing
First: Image Scaling
Image scaling, no transparent color processing
The code is as follows:
function thumn($background, $width, $height, $newfile) { list($s_w, $s_h)=getimagesize($background);//获取原图片高度、宽度 if ($width && ($s_w < $s_h)) { $width = ($height / $s_h) * $s_w; } else { $height = ($width / $s_w) * $s_h; } $new=imagecreatetruecolor($width, $height); $img=imagecreatefromjpeg($background); imagecopyresampled($new, $img, 0, 0, 0, 0, $width, $height, $s_w, $s_h); imagejpeg($new, $newfile); imagedestroy($new); imagedestroy($img); } thumn("images/hee.jpg", 200, 200, "./images/hee3.jpg");
Second: Adding watermarks to pictures
Adding text watermarks to pictures
function mark_text($background, $text, $x, $y){ $back=imagecreatefromjpeg($background); $color=imagecolorallocate($back, 0, 255, 0); imagettftext($back, 20, 0, $x, $y, $color, "simkai.ttf", $text); imagejpeg($back, "./images/hee7.jpg"); imagedestroy($back); } mark_text("./images/hee.jpg", "细说PHP", 150, 250);
Part 2: Variable variables
1, Variable variables
2. Variable function
$a="function"; $a teststr() { return "adfasd"; } $b="teststr"; echo $b();
3. Variable class
$a="b"; $$a="c"; echo $b;
Part 3: File operation (PHP operation file)
One: readfile() function
Example one:
<?php echo readfile("webdictionary.txt"); ?>
Two: fopen();Open file
(1). fopen(1,2);
1. File name
2. Open mode
Mode Description
r Open the file as read-only. The file pointer starts at the beginning of the file.
w Open the file for writing only. Delete the contents of the file or create a new file if it does not exist. The file pointer starts at the beginning of the file.
a Open the file for writing only. Existing data in the file will be preserved. The file pointer starts at the end of the file. Create a new file if the file does not exist.
x Create a new file to write only. Returns FALSE and an error if the file already exists.
r Open the file for reading/writing, and the file pointer starts at the beginning of the file.
w Open the file for reading/writing. Delete the file contents or create a new file if it does not exist. The file pointer starts at the beginning of the file.
a Open the file for reading/writing. Data already in the file will be retained. The file pointer starts at the end of the file. Create new file if it does not exist.
x Create new files for reading/writing. Returns FALSE and an error if the file already exists.
die
.
#(3). filesize() Get the file size
filesize(1);
1.File name
(4).fclose(1) Close the file pointer
fclose(1)
1. File pointer
Example 2:
<?php $myfile = fopen("webdictionary.txt", "r") or die("Unable to open file!"); echo fread($myfile,filesize("webdictionary.txt")); fclose($myfile); ?>
Example 3:
<?php $myfile = fopen("webdictionary.txt", "r") or die("Unable to open file!"); echo fgets($myfile); fclose($myfile); ?>
<?php $myfile = fopen("webdictionary.txt", "r") or die("Unable to open file!"); // 输出单行直到 end-of-file while(!feof($myfile)) { echo fgets($myfile) . "<br>"; } fclose($myfile); ?>
(7) fwrite() writes to the file
<?php $myfile = fopen("newfile.txt", "w") or die("Unable to open file!"); $txt = "Bill Gates\n"; fwrite($myfile, $txt); fclose($myfile); ?>
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