Search more efficiently with ugrep
Grep is one of the oldest Unix commands. The abbreviation "grep" stands for Global/Regular Expression/Print or Global search for a Regular Expression and Print out matched lines. It picks up on the syntax of the original Unix editor, QED, which used g/re/p to search for patterns in text files. In addition to fixed search terms, it can also search for patterns with wildcard characters. The GNU variant of grep is normally installed on Linux. It extends the features of the original grep in some places, for example, allowing recursive searching in directories.
Another variant of grep, agrep (approximate grep) [1], extends text searching to include fuzzy searches. It also finds near misses as long as the differences are below a specified threshold, known as the word distance. This is calculated from the necessary permutations, deletions, and additions of letters that convert the search pattern into the actual data.
In addition, there are some variants of grep that also find search patterns in certain archive types, such as ZIP files. These programs are relatively slow, since they first need to unpack the archive. However, all grep variants used on Linux can also read data from pipes via the standard input channel and write the results to the standard output channel for searching in archives (Listing 1).
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Plasma Ends LTS Releases
The KDE Plasma development team is doing away with the LTS releases for a good reason.
-
Arch Linux Available for Windows Subsystem for Linux
If you've ever wanted to use a rolling release distribution with WSL, now's your chance.
-
System76 Releases COSMIC Alpha 7
With scores of bug fixes and a really cool workspaces feature, COSMIC is looking to soon migrate from alpha to beta.
-
OpenMandriva Lx 6.0 Available for Installation
The latest release of OpenMandriva has arrived with a new kernel, an updated Plasma desktop, and a server edition.
-
TrueNAS 25.04 Arrives with Thousands of Changes
One of the most popular Linux-based NAS solutions has rolled out the latest edition, based on Ubuntu 25.04.
-
Fedora 42 Available with Two New Spins
The latest release from the Fedora Project includes the usual updates, a new kernel, an official KDE Plasma spin, and a new System76 spin.
-
So Long, ArcoLinux
The ArcoLinux distribution is the latest Linux distribution to shut down.
-
What Open Source Pros Look for in a Job Role
Learn what professionals in technical and non-technical roles say is most important when seeking a new position.
-
Asahi Linux Runs into Issues with M4 Support
Due to Apple Silicon changes, the Asahi Linux project is at odds with adding support for the M4 chips.
-
Plasma 6.3.4 Now Available
Although not a major release, Plasma 6.3.4 does fix some bugs and offer a subtle change for the Plasma sidebar.