![]() I see a lot of people trying to put together phone regex's and struggling (hey, no worries.they're complicated). ![]() Matching a backslash character can be confusing, because double escaping is needed in the pattern: first for PHP, second for the regex engine The numbering of the nodes in simplexml starts from zero, but from 1 in DOM xpath objects Here is a function that decreases the numbers inside a string (useful to convert DOM object into simplexml object)Į.g.: decremente_chaine("somenode->anode->achildnode") will return "somenode->anode->achildnode" This means using or | statements within the pattern, it gets quite long so if your log file is not getting any false positives you might just stick to a simpler pattern.Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures Functions Classes and Objects Namespaces Enumerations Errors Exceptions Fibers Generators Attributes References Explained Predefined Variables Predefined Exceptions Predefined Interfaces and Classes Predefined Attributes Context options and parameters Supported Protocols and Wrappers Security Introduction General considerations Installed as CGI binary Installed as an Apache module Session Security Filesystem Security Database Security Error Reporting User Submitted Data Hiding PHP Keeping Current Features HTTP authentication with PHP Cookies Sessions Dealing with XForms Handling file uploads Using remote files Connection handling Persistent Database Connections Command line usage Garbage Collection DTrace Dynamic Tracing Function Reference Affecting PHP's Behaviour Audio Formats Manipulation Authentication Services Command Line Specific Extensions Compression and Archive Extensions Cryptography Extensions Database Extensions Date and Time Related Extensions File System Related Extensions Human Language and Character Encoding Support Image Processing and Generation Mail Related Extensions Mathematical Extensions Non-Text MIME Output Process Control Extensions Other Basic Extensions Other Services Search Engine Extensions Server Specific Extensions Session Extensions Text Processing Variable and Type Related Extensions Web Services Windows Only Extensions XML Manipulation GUI Extensions Keyboard Shortcuts ? This help j Next menu item k Previous menu item g p Previous man page g n Next man page G Scroll to bottom g g Scroll to top g h Goto homepage g s Goto search You have to account for the fact that the max number is 255 in each octet position. If you want an even more accurate regex pattern to match an ip address, it gets quite complex and lengthy. - a simple and short pattern, takes advantage the length of the IP being between 6 and 15 characters.We will improve the pattern in the next one. +\.+\.+\.+ - this is the one used above, the shortfall is that it can match more than 3 numbers in each octet position.Here are a few regular expressions that can be used to match IP addresses in a log file (note I have taken out some of the escaping): Other regex patterns to match an IP addressĪs I mentioned the pattern we are using above is not perfect, but it works pretty well and is reasonably easy to understand. Pretty handy right? It works great for counting or finding ip addresses in nginx, apache or any kind of log files with ip addresses. The above will put them in order from least to greatest, you can pipe the result to tail if you only want to see the top N IP addresses! The ip counts are not in order, so we can pass our results through sort again, this time with the -n flag to use a numeric sort. Now we can use the -c flag for uniq to display counts: grep -o "\+\.\+\.\+\.\+" httpd.log | sort | uniq -c Show me the number of times each IP shows up in the log We can do that with the sort command, like so: grep -o "\+\.\+\.\+\.\+" httpd.log | sort | uniq We can use the uniq command to remove duplicate ip addresses, but uniq needs a sorted input. How can I find unique ip addresses in a log file? You just need to come up with a regular expression to match an IP, I'll use this: "\+\.\+\.\+\.\+" it's not perfect, but it will work. This feature turns out to be pretty handy, let's say you want to find all the IP addresses in a file. This tells grep to only output the matched pattern (instead of lines that mach the pattern). I've been using grep to search through files on linux / mac for years, but one flag I didn't use much until recently is the -o flag.
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