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Summary of image processing and file operation methods in php (with code)
Summary of image processing and file operation methods in php (with code)
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);
?>(5) fgets(1) Read a line of data1 .File pointer
Example 3:
<?php
$myfile = fopen("webdictionary.txt", "r") or die("Unable to open file!");
echo fgets($myfile);
fclose($myfile);
?>Example 4: feof(1) Detect whether the file has reached the end
<?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);
?>(6) fgetc(1) ) Read a character
(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);
?>Related recommendations:
PHP image operation php image processing p image software download php image upload
Use php and imagemagick to handle the upload and scaling of image files
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