- #LINUX SEARCH A FILE FOR A STRING HOW TO#
- #LINUX SEARCH A FILE FOR A STRING CODE#
- #LINUX SEARCH A FILE FOR A STRING ZIP#
- #LINUX SEARCH A FILE FOR A STRING WINDOWS#
Here’s a template of what that looks like. Grep helps you search through files, looking for patterns.
#LINUX SEARCH A FILE FOR A STRING WINDOWS#
It’s since made its way onto Linux machines and even into the Windows world. Grep (actually, “grep” - you don’t capitalize it) is a command line utility originating in the Unix world. When you’re done reading, you’ll understand the basics enough to search your files with grep-regex. To do that, I’ll walk through a hypothetical example of trying to extract some information.
#LINUX SEARCH A FILE FOR A STRING HOW TO#
So let’s look at how to take the edge off of that and get you familiar with this file search technique. Again, grep and regex can rescue you here.īut with that versatility comes a bit of a learning curve. Or perhaps you are an avid note-taker, but you are too busy jotting them down to worry about organization. Imagine: you fret about organizing your files, because you can never seem to find where you put the last file. You can also search with extremely limited access to your environment, and if you get creative, you can find just about anything. Using this combination of tools, you can search files of any sort and size. Learning Grep and Regex Teaches You a Powerful Search Technique And finally, we will wrap up with some advice on judicious use of these tools.Then, we will dive into some examples: we will show examples of grep and regex separately, then we will show how you can use them both together for powerful searching.Next, we are going to discuss what both grep and regex are.We will show a common problem we have when manually searching.In this article, you will learn why grep and regex together are so powerful. Today, we’re going to look at one of the most versatile ways to search a file: using grep and regex (short for regular expression). What, exactly, are you looking for in the file?.How do you search through a file? On the surface, this might seem like sort of a silly question.īut somewhere between the common-sense answer for many (“double click it and start reading!”) and the heavily technical (“command line text grep regex”) lies an interesting set of questions. Thanks to jan61 for the elegant Linux command covered in this post that makes it easy to search contents of files in JARs for a given string.To understand the grep regex combination, ask yourself a question first. The & symbols indicate that the echo command will be run to print out the file name with content matching the grep-ed for String if (and only when) the grep command returns a successful status (0).Īll of the above are only executed against files with.
#LINUX SEARCH A FILE FOR A STRING CODE#
The provided -q parameter specifies "quiet" mode in which nothing is written to standard output and the grep exits immediately with zero status code upon detecting a match. More specifically, %p is a directive to the -printf flag of the find command that directs it to include the found file's name.Įach found file is unzipped and its content directed to standard output where it is piped to a grep command to search for the provided text String. The %p is associated with the Linux find command.
#LINUX SEARCH A FILE FOR A STRING ZIP#
The Linux unzip command "list, test and extract compressed files in a ZIP archive." The -c passed to the unzip command "extract files to stdout" and includes the name of the extracted files with that standard output. I start analyzing the command from the inside and move outward. The two versions of the command shown immediately above will work as-is and the rest of this blog post focuses on how the command works. Linux Script Form of Above Command printf "Searching JARs for string '$' & echo %p\n" | sh Here is an example script that could be used. I like to have this in script form (or as an alias) because that name is easier to remember than typing in that entire command each time. iname '*.jar' -printf "unzip -c %p | grep -q '' & echo %p\n" | sh Here is that simple line (the token represents the string to search for): This search isn't searching for the names of the entries themselves in the JAR, but rather is searching the contents of each searchable file in the JAR. class file within jar (for strings), a single line command in Linux nicely does the job of searching JARs recursively from a given directory for a given String. In this blog post, I look at that example more closely.Īs documented on the thread searching contents of. I was glad I looked first, because the Linux-based approach provided by "jan61" satisfied my need nicely. The alternative needed to be easy to use, freely available, and not bogged down with a load of dependencies. I recently thought about writing a Groovy script to search JARs for a specific string, but decided to first look for an alternative rather than writing a script.