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The title speaks for itself really. I only want to know if it exists, not where it is. Is there a one liner to achieve this?
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Grep is a Linux / Unix command-line tool used to search for a string of characters in a specified file. The text search pattern is called a regular expression. When it finds a match, it prints the line with the result. The grep command is handy when searching through large log files.
Without a doubt, grep is the best command to search a file (or files) for a specific text. By default, it returns all the lines of a file that contain a certain string. This behavior can be changed with the -l option, which instructs grep to only return the file names that contain the specified text.
You can use grep command or find command as follows to search all files for a string or words recursively.
File.open(filename).grep(/string/) This loads the whole file into memory (slurps the file). You should avoid file slurping when dealing with large files. That means loading one line at a time, instead of the whole file.
File.foreach(filename).grep(/string/) It's good practice to clean up after yourself rather than letting the garbage collector handle it at some point. This is more important if your program is long-lived and not just some quick script. Using a code block ensures that the File object is closed when the block terminates.
File.foreach(filename) do |file| file.grep(/string/) end If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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