Search more efficiently with ugrep
Filters
Ugrep tries to determine the type of an examined file based on the data it contains, the file name extension, and the signature (the "magic byte"). In this way, the search can be specially prepared for certain file types (i.e., filtered).
Here the filter extracts the text components from the data streams. These filters execute a command, a script, or a specific function, with pipes if necessary. They are prepended to the search process via the --filter=<Filter>
or --filter-magic-label=<Label>:<MagicByte>
option.
In the form --filter=<filter>
, the <filter>
consists of an expression of the form <Ext>:<command line>
. <Ext>
is a comma-separated list of file name extensions for which you want the filter to apply, such as .doc,.docx,.xls
. The *
character is a special case that acts on all files, especially those for which there are no other filters.
The <command>
line must be constructed to read input via the standard input channel and write the results to the standard output channel. Typical commands include cat
(pass everything) and head
(pass the first lines of text), but tools like exiftool
(extract and pass metadata) or pdftotext
(extract text from PDFs) can also be included this way. Some commands, like pdftotext
, require options to work correctly – in this case pdftotext % -
. You then need to quote spaces in the command lines to protect them:
--filter='pdf:pdftotext % -'
The --filter-magic-label=<Label>:<Magic>
option lets you extend the filtering mechanism to data streams that ugrep then classifies by reference to the magic byte. Details can be found in the man page.
Multiple filters can be specified as comma-separated lists. A combined definition for PDF and Office documents might look like the one shown in Listing 3.
Listing 3
Combined Filter Definition
--filter="pdf:pdftotext % -,odt,doc,docx,rtf,xls,xlsx,ppt,pptx:soffice --headless --cat %"
Conclusions
Ugrep belongs on every computer. It replaces and complements the standard commands quite excellently, and anyone who has to deal with text searches should familiarize themselves with it. The incremental search alone is so useful that it more than justifies the minimal training time.
Infos
« Previous 1 2
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Direct Download
Read full article as PDF:
Price $2.95
News
-
KaOS 2022.06 Now Available With KDE Plasma 5.25
The newest iteration of KaOS Linux not only adds the latest KDE Plasma desktop but sets LibreOffice as the default.
-
Manjaro 21.3.0 Is Now Available
Manjaro “Ruah” has been released and includes the latest Calamares installer, GNOME 42, and much more.
-
SpiralLinux is a New Linux Distribution Focused on Simplicity
A new Linux distribution, from the creator of GeckoLinux, is a Debian-based operating system with a focus on simplicity and ease of use.
-
HP Dev One Linux Laptop is Now Available for Pre-Order
The System76/HP collaboration Dev One laptop, geared toward developers, is now available for pre-order.
-
NixOS 22.5 Is Now Available
The latest release of NixOS with a much-improved package manager and a user-friendly graphical installer.
-
System76 Teams up with HP to Create the Dev One Laptop
HP and System76 have come together to develop a new laptop, powered by Pop!_OS and aimed toward developers.
-
Titan Linux is a New KDE Linux Based on Debian Stable
Titan Linux is a new Debian-based Linux distribution that features the KDE Plasma desktop with a focus on usability and performance.
-
Danielle Foré Has an Update for elementary OS 7
Now that Ubuntu 22.04 has been released, the team behind elementary OS is preparing for the upcoming 7.0 release.
-
Linux New Media Launches Open Source JobHub
New job website focuses on connecting technical and non-technical professionals with organizations in open source.
-
Ubuntu Cinnamon 22.04 Now Available
Ubuntu Cinnamon 22.04 has been released with all the additions from upstream as well as other features and improvements.