//执行脚本 =生成txt文本
shell_exec('/usr/local/bin/pdftotext -layout '.$file_url(这里是文件的路劲));
-layout 参数可切换 -p等等 一个会换行 一个不会
$filename = str_replace(strrchr($file_url, '.'), '', $file_url);//文件名
//获取文件内容 去除空格及不定义字符
$content = file_get_contents($filename.'.txt');
$count_txt = $content;
$oldchar=array(" "," ","\t","\n","\r");
$newchar=array("","","","","");
$content = str_replace($oldchar,$newchar,$content);
输出|PDF内容字符串