检查exec（）是否成功运行

Question

我一直在试图让知道知道如果PHP中的exec()命令执行成功与否，所以我可以相应地回复某些消息。 我试了下面这段代码，但它的问题是，exec()是否成功运行，它总是echo "PDF not created"，并从未成功创建回声pdf。请让我知道我可以在EXEC的执行（执行检查），这样我就可以相应地回响消息 感谢，

<?php 
if (exec('C://abc//wkhtmltopdf home.html sample.pdf')) 
echo "PDF Created Successfully"; 
else 
echo "PDF not created"; 
?> 

Answer 1

根据PHP的exec quickref，你可以通过指针获得的输出和状态命令。

<?php 
exec('C://abc//wkhtmltopdf home.html sample.pdf', $output, $return); 

// Return will return non-zero upon an error 
if (!$return) { 
    echo "PDF Created Successfully"; 
} else { 
    echo "PDF not created"; 
} 
?> 

如果要列举可能出现的错误，你可以在hiteksoftware

Answer 2

找到代码在一个简单的例子：

$ip = "192.168.0.2"; 
$exec = exec("ping -c 3 -s 64 -t 64 ".$ip, $output, $return); 
echo $exec; 
echo "<br />----------------<br />"; 
print_r($output); 
echo "<br />----------------<br />"; 
print_r($return); 

在无法ping或错误的情况下。 （一）

---------------- 
Array ([0] => PING 192.168.0.2 (192.168.0.2) 64(92) bytes of data. [1] => [2] => --- 192.168.0.2 ping statistics --- [3] => 3 packets transmitted, 0 received, 100% packet loss, time 2016ms [4] =>) 
---------------- 
1 

在成功（ZERO）

rtt min/avg/max/mdev = 4.727/18.262/35.896/13.050 ms 
---------------- 
Array ([0] => PING 192.168.0.2 (192.168.0.2) 64(92) bytes of data. [1] => 72 bytes from 192.168.0.2: icmp_req=1 ttl=63 time=14.1 ms [2] => 72 bytes from 192.168.0.2: icmp_req=2 ttl=63 time=35.8 ms [3] => 72 bytes from 192.168.0.2: icmp_req=3 ttl=63 time=4.72 ms [4] => [5] => --- 192.168.0.2 ping statistics --- [6] => 3 packets transmitted, 3 received, 0% packet loss, time 2003ms [7] => rtt min/avg/max/mdev = 4.727/18.262/35.896/13.050 ms) 
---------------- 
0 

Answer 3

正确的方法是，以检查$ return_var没有设置为零，因为它只是设置为零时的情况下，它是成功的。在某些情况下，exec可能会失败，并且return_var没有设置为任何值。例如。如果服务器在执行期间耗尽了磁盘空间。

<?php 
exec('C://abc//wkhtmltopdf home.html sample.pdf', $output, $return_var); 
if($return_var !== 0){ // exec is successful only if the $return_var was set to 0. !== means equal and identical, that is it is an integer and it also is zero. 
    echo "PDF not created"; 
} 
else{ 
    echo "PDF Created Successfully"; 
} 

?> 

注意：不要初始化$ return_var零