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Old 03-17-2005, 12:36 PM   #1
bwreath
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problems with regular expression and grep


Hi,

I would appreciate help with the following.

if $userinput is the variable representing user input.

If the search term is

$newuserinput = "[^0123456789.:]".$userinput."[^0123456789.:]";

and within a php file I call

exec ($mydirectory."grep -E "newuserinput $mystring", $searchoutput, $searchstatus);

I have found that this grep command works most of the time except when
there is a space character in the variable $userinput.
What can I do to this expression to make it work when there are spaces
in the $userinput variable?

thanks!
 
Old 03-17-2005, 12:46 PM   #2
Matir
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I am curious why you don't just use the regular expression engine built into php... it would be much more efficient than a call to exec. If you still want to exec, you'll need to quote the regexp.
 
Old 03-17-2005, 01:05 PM   #3
bwreath
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Hi Matir,

Thanks for your help. If I still want to use exec how would I quote the regexp

I am already using the following in my php file.
$newuserinput = "[^0123456789.:]".$userinput."[^0123456789.:]";

exec ($mydirectory."grep -E $newuserinput $mystring", $searchoutput, $searchstatus);

So would I change the line with the $newuserinput to:

$newuserinput = "[^0123456789.:]"."$userinput"."[^0123456789.:]";

ie. the $userinput variable input quoted?

thanks!
 
Old 03-17-2005, 02:24 PM   #4
bwreath
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Actually, I tried quoting the $userinput variable recently. It doesn't work.

Any ideas?

$newuserinput = "[^0123456789.:]"."$userinput"."[^0123456789.:]";


thanks!
 
Old 03-17-2005, 02:54 PM   #5
ahh
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Quote:
Originally posted by bwreath
Actually, I tried quoting the $userinput variable recently. It doesn't work.

Any ideas?

$newuserinput = "[^0123456789.:]"."$userinput"."[^0123456789.:]";


thanks!
This solved a similar problem for me.
Code:
userinput=$(cat $userinput | tr " " "_")

$newuserinput="[^0123456789.:]"."$(cat $userinput | tr "_" " ")"."[^0123456789.:]";
You would have to replace "_" with a character that wont be in $userinput , of course.
 
Old 03-17-2005, 03:28 PM   #6
Matir
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make your exec command like "grep '$userinput'" or similar. (Should quote it properly).
 
Old 03-18-2005, 01:43 PM   #7
bwreath
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Thanks Matir,

I used your suggestion and the grep worked properly.

also thanks ahh I used a modification of your idea for another part of my code
since spaces weren't allowed somewhere else
 
  


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