The Bourne Again Shell script presented in this article demonstrates techniques related to capturing and logging output (standard output and standard error stream) of a script into a log file while also delivering it to the regular output destinations (for example the terminal or whatever the caller has chosen to redirect to). Some questions are […]
Artikel in Kategorie "GNU/Linux"
Make a Bourne Again Shell Script Log its Output to a File
20. August 2023 in Administration, GNU/Linux, Programmierung.
Using sed or awk to ensure a specific last Line in a Text
20. August 2023 in GNU/Linux, Programmierung.
Given a file containing bytes of text with lines separated by the newline character (\n), one of these lines can be said to be „the last line of the file“; it is a sequence of bytes occurring in the file, for which holds: The sequence contains no newline character, and the sequence is followed by […]
Determine IPv4 Addresses of a Libvirt Qemu-KVM Domain
1. Juli 2023 in Administration, GNU/Linux, Technik.
In the VM, on Redhat-likes, make sure that the Qemu guest agent is installed: dnf install qemu-guest-agent On Debian-likes, execute: apt install qemu-guest-agent For Microsoft Windows guests, there are some tutorials on the web, see for example [1]. On the HV, execute: virsh qemu-agent-command –domain myvm \ ‚{„execute“:“guest-network-get-interfaces“}‘ | \ jq -r ‚ [.return[] | […]
Removing the Builtin Inline CSS from WordPress
27. August 2022 in Programmierung.
Should you – as i did – wonder why WordPress renders a bucket of inline CSS into the HTML output (such as –wp–preset–font-size–normal in <html> or –wp–preset–color–white in <body>): This is done to accomodate frontend editing with Gutenberg. If you – as i do – are not using Gutenberg frontend editing, then the following PHP […]
Updated Common Prefix Notation Transformation
2. Februar 2024 in Programmierung.
This is an update to my previous article on determining the common prefixes of a set of strings (passed a sequence of lines) and printing them in common prefix notation (CPN). The problem of reconstructing strings from the original input that are complete prefixes of other input strings is addressed. The code is now in […]
Find Files by Size given in Bytes
20. August 2023 in Administration, GNU/Linux, Programmierung.
Some examples: Find files in current directory that have a size of 400 bytes or more: sfind -min 400 Find files in /etc that have a size of 50 kilobytes (1 kilobyte = 1024 bytes) or more: sfind -dir /etc -min 50k Find files in /var with size between 100 and 500 megabytes, suppress warnings, […]
Print XDG Desktop Definition for Application
20. August 2023 in Administration, GNU/Linux.
For an application given by „application name“ or „executable name“, output the corresponding .desktop file, if any: #!/bin/sh IFS=“:“ xdg_data_dirs=${XDG_DATA_DIRS:-/usr/local/share:/usr/share} search=$1 for i in $xdg_data_dirs ; do a=“$i/applications“ [ -d $a ] && for d in „$a“/*.desktop ; do grep -q -e „^Name=.*$search“ -e „^Exec=.*$search“ „$d“ && { echo „# $d:“ grep -Ev ‚^(Comment|GenericName|Keywords|Name\[)‘ „$d“ […]