Executing system command in PHP differs when using browser and when using command line
I have to execute a Linux more command in PHP from a particular offset, format the result and display the result in the browser.
My code for the above is:
<html>
<head>
<META HTTP-EQUIV=REFRESH CONTENT=10>
<META HTTP-EQUIV=PRAGMA CONTENT=NO-CACHE>
<title>Runtime Access log</title>
</head>
<body>
<?php
$moreCommand = "more +3693 /var/log/apache2/access_log | grep -v -e '.jpg' -e '.jpeg' -e '.css' -e '.js' -e '.bmp' -e '.ico'| wc -l";
exec($moreCommand, $accessDisplay);
echo "<br/>No of lines are : $accessDisplay[0] <br/>";
?>
</body>
</html>
The output at the browser is: No of lines are : 3428 (This is wrong)
While executing the same command using command line gives a different output. My code snippet for the same is:
<?php
$moreCommand = "more +3693 /var/log/apache2/access_log | grep -v -e '.jpg' -e '.jpeg' -e '.css' -e '.js' -e '.bmp' -e '.ico'| wc -l";
exec($moreCommand, $accessDisplay);
echo "No of lines are : $accessDisplay[0] \n";
?>
The output at the command line is: No of lines are : 279 (This is correct)
W开发者_如何学JAVAhile executing the same command directly in command line, gives me output as 279.
I am unable to understand why the output of the same command is wrong in the browser. Its actually giving the word count of lines, ignoring the offset parameter.
I would recommend that you drop the shell pipeline and parse the logfile in PHP directly. Much more control. Much less hassle and definitely more robust.
What would the difference be in:
$moreCommand = "more -f -99999 +3693 /var/log/apache2/access_log | grep -v -e '.jpg' -e '.jpeg' -e '.css' -e '.js' -e '.bmp' -e '.ico' -c"
(-f & -num to more, -c to grep instead of | wc -l)
In debugging it could also be usefull to examine the exact output without count of the 2 (perhaps using head or tail), as there might be shell differences between the cli & webserver users.
OK, that was wrong, can reproduce more not getting the '+', alternative:
$moreCommand = "tail --lines=`wc -l /var/log/apache2/access_log | awk '{print $1 - 3693}' | grep -v -e '.jpg' -e '.jpeg' -e '.css' -e '.js' -e '.bmp' -e '.ico' `
加载中,请稍侯......
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