global variables

$file_size_max = 1024 * 1024 * 2; // 2M

function print_file_in_dir($dir) {
# dir: ./upload/
files=scandir(files = scandir(files=scandir(dir);
foreach ($files as KaTeX parse error: Expected '}', got 'EOF' at end of input: … { if (file != ‘.’ && $file != ‘…’) {
echo(“file:” . $dir . ‘/’ . $file . “
”);
}
}
}

function delete_old_file($file_path) {
# file_path: timestamp_filename.png
# if timestamp is ten minutes ago, delete the file
filename=substr(file_name = substr(filen​ame=substr(file_path, strrpos($file_path, ‘/’) + 1);
timestamp=substr(timestamp = substr(timestamp=substr(file_name, 0, strrpos($file_name, ‘_’));
$timestamp_now = time();
$timestamp_ago = timestampnow−600;if(timestamp_now - 600; if (timestampn​ow−600;if(timestamp < KaTeX parse error: Expected '}', got 'EOF' at end of input: … unlink(file_path);
return true;
}
return false;
}

function check_old_file_in_dir($dir) {
# dir: ./upload/
files=scandir(files = scandir(files=scandir(dir);
foreach ($files as KaTeX parse error: Expected '}', got 'EOF' at end of input: … { if (file != ‘.’ && KaTeX parse error: Expected '}', got 'EOF' at end of input: …elete_old_file(dir . $file);
}
}
}

function test_input($data){
# copy from: https://www.runoob.com/php/php-form-validation.html
data=trim(data = trim(data=trim(data);
data=stripslashes(data = stripslashes(data=stripslashes(data);
data=htmlspecialchars(data = htmlspecialchars(data=htmlspecialchars(data);
return $data;
}

function check_file($_file) {
# check file type, size. Allow type: png, jpg, jpeg
# $_file: $_FILES[“file”]
$file_type = $_file[“type”];
$file_size = file["size"];if(_file["size"]; if (f​ile["size"];if(file_type != “image/png” && $file_type != “image/jpg” && $file_type != “image/jpeg” || $file_size > $GLOBALS[‘file_size_max’]) {
echo "文件类型或大小不符合要求: " . $file_type . " " . $file_size;
return false;
}
return true;
}

function img_to_base64(KaTeX parse error: Expected '}', got '#' at position 18: …le_path) { #̲ file_path: ./u…fp = fopen($file_path, “r”)) {
content=fread(content = fread(content=fread(fp, filesize(filepath));fclose(file_path)); fclose(filep​ath));fclose(fp);
filebase64=′data:image/png;base64,′.base64encode(file_base64 = 'data:image/png;base64,' . base64_encode(fileb​ase64=′data:image/png;base64,′.base64e​ncode(content);

    return $file_base64;
}
return false;

}