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Accepted
vladimir pavloski
Asked: 2018-12-03 15:06:40 +0800 CST

Is it possible to use grep command nested?

  • 772

I mean, when I run

dpkg -s thunar | grep "Depends"

it displays all dependencies for thunar file manager. How to run, for example

dpkg -s thunar | grep "Depends" | grep "gtk"

to display only dependencies containing gtk in its name ?

command-line grep

4 Answers

  1. I would split up the packages in separate lines to be grepped with tr:

    $ dpkg -s vivaldi-stable | grep "^Depends" | tr ',' '\n' | grep "gtk"
 libgtk-3-0 (>= 3.21.4)
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  2. grep deals with lines, so after initial match for Depends line, you need to split the line somehow. It can be done with grep -Po flags, but that can be slightly complex. A simpler way and only via one pipeline is to use awk:

    $ dpkg -s nautilus | awk '/Depends/{for(i=1;i<=NF;i++) {if($i~/gtk/) printf "%s\n",$i;}}'
libgtk-3-0
$ dpkg -s gedit | awk '/Depends/{for(i=1;i<=NF;i++) {if($i~/gtk/) printf "%s\n",$i;}}'
libgtk-3-0
libgtksourceview-3.0-1
gir1.2-gtk-3.0
gir1.2-gtksource-3.0

    This matches appropriate line and iterates over each "field" or space-separated column in the line, checking if it contains gtk.

    • 1

  3. The way you type your example should also work but you can do...

    dpkg -s thunar | grep 'Depends.*gtk'

    ... if gtk is always after Depends

    Example:

    $ dpkg -s nautilus | grep -E 'Depends.*gtk'
Depends: libatk1.0-0 (>= 1.32.0), libc6 (>= 2.14), libcairo-gobject2 (>= 1.10.0), libcairo2 (>= 1.14.0), libdbusmenu-glib4 (>= 0.4.2), libexempi3 (>= 2.4.0), libexif12 (>= 0.6.21-1~), libgail-3-0 (>= 3.0.0), libgdk-pixbuf2.0-0 (>= 2.25.2), libglib2.0-0 (>= 2.51.2), libgnome-autoar-0-0 (>= 0.2.1), libgnome-desktop-3-17 (>= 3.18.1), libgtk-3-0 (>= 3.22.6), libnautilus-extension1a (= 1:3.26.4-0ubuntu7), libpango-1.0-0 (>= 1.20.0), libpangocairo-1.0-0 (>= 1.14.0), libselinux1 (>= 2.0), libtracker-sparql-2.0-0 (>= 0.10.0), libunity9 (>= 3.4.6), libx11-6, libzeitgeist-2.0-0 (>= 0.9.9), nautilus-data (= 1:3.26.4-0ubuntu7), shared-mime-info (>= 0.50), desktop-file-utils (>= 0.7), gvfs (>= 1.3.2), libglib2.0-data, gsettings-desktop-schemas (>= 3.8.0)
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  4. Best Answer
    $ dpkg -s nautilus | grep "Depends" | grep -o "\S*gtk\S*"
libgtk-3-0

    Explanation:

    • -o - Print only the matching part of the line
    • \S* - Zero or more non-whitespace characters

    If you want the version number too:

    $ dpkg -s nautilus | grep "Depends" | grep -o "\S*gtk[^,]*"
libgtk-3-0 (>= 3.9.12)
    • [^,]* - Zero or more characters which are not commas
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