We can also specify a range of characters or numbers rather than a set. "ky" matches only "key", "kay", and "k1y". This performs a logical OR to identify a match from the specified characters. Matches any item specified within the square brackets, be it a set or a range of characters. "linux|windows" matches either "linux" or "windows". Performs a logical OR relationship between two strings or even two regex expressions. Also, "key$" matches any lines ending with "key" "o$" matches any string ending with "o", like "zoro". This also applies to strings, where "^Linux" matches any line starting with "Linux". "^z" matches any string starting with "z", like "zaaiy" or "zebra", but not "azerty". This also means that "\\" negates the effect of the second backslash and matches it as is "\". Works as an escape character to interpret the subsequent special character literally. "z*" matches "z", "zz", "zzz", but not "zzxz" or any other character. Matches the preceding character zero or more times. This means"xxz" or "xyz" but not "xz" or "xyyz". "x.z" matches any 3-character string that starts with x and ends with z. Matches any single character and works similarly to the ? in shell globs. Luckily, there is consistency across all types and we may summarize them in the following wildcard characters: Elements One thing to consider is that there isn’t just one set of these regex characters, meaning they can be interpreted differently based on what type of regex you're using. By combining these into a string, you can specify a template to match and filter text. Regular expressions are characters or text fragments with special meaning. To use regular expressions effectively, you'll need to get a grasp of how they work. You can use regex in most text-processing commands right out of the box, including the find command. You may think of regex as an advanced way of searching for complex patterns without constructing lengthy Linux commands. Regular expressions (regex) are pattern-matching notations just like globular expressions, but they're more expressive. Regex And Globbing Patterns Aren’t The Same In this tutorial, we'll briefly discuss what are regular expressions, learn how to apply them with find, and then we'll check some practical examples where regex outshines the standard wildcards. That's when we bring out the big guns – regular expressions (or regex for short) to describe our patterns in much finer detail. Here's the thing: these wildcards can be effective, but they fall short in many cases where we want to define more advanced and complex patterns. We often use it for finding files based on matching their filenames using the shell's wildcards (or glob expressions). Examples of copying a file, copying multiple files, copying a directory, taking a backup when copying and preserving file attributes when copying.In Linux-based systems, the go-to command to locate and search for files is the find command. Tutorial on using cp, a UNIX and Linux command for copying files and directories. Linux and Unix cp command tutorial with examples Examples of creating an empty file, updating access and modification time, updating just access time, updating just modification time and setting timestamps in the past. Tutorial on using touch, a UNIX and Linux command for changing file timestamps. Linux and Unix touch command tutorial with examples Examples of killing a process, sending a SIGTERM, listing signal names and numbers, and handling 'operation not permitted' errors. Tutorial on using kill, a UNIX and Linux command for terminating a process. Linux and Unix kill command tutorial with examples You can edit it here and send me a pull request. To access the help menu press h within more.
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