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How can I check if a URL exists via PHP?

... Here: $file = 'http://www.example.com/somefile.jpg'; $file_headers = @get_headers($file); if(!$file_headers || $file_headers[0] == 'HTTP/1.1 404 Not Found') { $exists = false; } else { $exists = true; } From here and right below the above post, there's a curl solution: func...
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How to write a caption under an image?

...x; text-align:center; } .images div span { display:block; } .margin_right { margin-right:50px; } .float { float:left; } .clear { clear:both; height:0; width:0; } HTML <div class="images"> <div class="float margin_right"> <a href="http://xyz.c...
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What APIs are used to draw over other apps (like Facebook's Chat Heads)?

... This one: Allows an application to open windows using the type TYPE_SYSTEM_ALERT, shown on top of all other applications. Very few applications should use this permission; these windows are intended for system-level interaction with the user. Constant Value: "android.permission.SYS...
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What is the correct way to start a mongod service on linux / OS X?

...lled mongo via homebrew and it included /usr/local/Cellar/mongodb/2.4.5-x86_64/homebrew.mxcl.mongodb.plist (and was properly configured for my installation). Just copied homebrew.mxcl.mongodb.plist into LaunchAgents and followed the rest of these instructions (substituting homebrew.mxcl.mongodb for ...
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remove legend title in ggplot

... You were almost there : just add theme(legend.title=element_blank()) ggplot(df, aes(x, y, colour=g)) + geom_line(stat="identity") + theme(legend.position="bottom") + theme(legend.title=element_blank()) This page on Cookbook for R gives plenty of details on how to customize ...
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How to validate an email address in PHP

...t way to check whether an email address is well-formed is to use the filter_var() function: if (!filter_var($email, FILTER_VALIDATE_EMAIL)) { // invalid emailaddress } Additionally you can check whether the domain defines an MX record: if (!checkdnsrr($domain, 'MX')) { // domain is not v...
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jQuery: checking if the value of a field is null (empty)

... "NULL". You want to check if it's an empty string instead: if ($('#person_data[document_type]').val() != ''){} or: if ($('#person_data[document_type]').val().length != 0){} If you want to check if the element exist at all, you should do that before calling val: var $d = $('#person_data[docum...
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Regular expression \p{L} and \p{N}

...not be using alternation when a character class would suffice: [\p{L}\p{N}_.-]* share | improve this answer | follow | ...
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PHP validation/regex for URL

...lieve I've run into issues, but I'm sure it's not exhaustive: $text = preg_replace( '#((https?|ftp)://(\S*?\.\S*?))([\s)\[\]{},;"\':<]|\.\s|$)#i', "'<a href=\"$1\" target=\"_blank\">$3</a>$4'", $text ); Most of the random junk at the end is to deal with situations like http:/...
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Total size of the contents of all the files in a directory [closed]

... the size the directory takes up on the disk. – anton_rh Sep 24 '18 at 11:59 add a comment  |  ...