Did you know ...
Search Documentation:
Predicate unsetenv/1
HOME
DOWNLOAD
SWI-Prolog
Sources/building
Docker images
Add-ons
Browse GIT
DOCUMENTATION
Manual
Packages
FAQ
Command line
PlDoc
Bluffers
▶
Prolog syntax
PceEmacs
HTML generation
License
Publications
Rev 7 Extensions
TUTORIALS
Beginner
▶
Getting started
Learn Prolog Now!
Simply Logical
Debugger
Development tools
Advanced
▶
Modules
Grammars (DCGs)
clp(fd)
Printing messages
PlDoc
Web applications
▶
Web applications
Let's Encrypt!
Pengines
Semantic web
▶
ClioPatria
RDF namespaces
Graphics
▶
XPCE
GUI options
Machine learning
▶
Probabilistic Logic Programming
External collections
▶
Meta level tutorials
For packagers
▶
Linux packages
COMMUNITY
Forum & mailing list
Blog
News
Report a bug
Submit a patch
Submit an add-on
Roadmap (on GitHub)
External links
Contributing
Code of Conduct
Contributors
SWI-Prolog items
COMMERCIAL
WIKI
Login
View changes
Sandbox
Wiki help
All tags
Documentation
Reference manual
Built-in Predicates
Operating System Interaction
shell/1
shell/2
getenv/2
setenv/2
unsetenv/1
setlocale/3
Windows-specific Operating System Interaction
Apple specific Operating System Interaction
Dealing with time and date
Controlling the swipl-win.exe console window
Packages
Availability:
built-in
unsetenv
(
+Name
)
Remove an environment variable from the environment. Some systems lack the underlying
unsetenv()
library function. On these systems
unsetenv/1
sets the variable to the empty string.