this post was submitted on 22 Sep 2025
22 points (92.3% liked)
Linux
58560 readers
954 users here now
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
Rules
- Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise.
- No misinformation
- No NSFW content
- No hate speech, bigotry, etc
Related Communities
Community icon by Alpár-Etele Méder, licensed under CC BY 3.0
founded 6 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
You're probably wanting
[ -z "${VAR1}" -a -z "${VAR2}" ]
. Note in bash that there are minor differences in how[ ]
and[[ ]]
tests are handled. You can pull up a handy cheat sheet of the operands on most distros by runningman test
, though you'll need to read through the CONDITIONAL EXPRESSIONS section ofman bash
if you want to see the minor differences of the single vs double square bracket commands (mostly whether locale applies to string order, as well as whether operands are evaluated in numeric comparisons).