Topics
Security
Data formats
Text
Linux and network
Encoding and conversion
Where to start
First steps
15 stages · From system basics and command input to navigation, files, text, and pipelines.
Track map 11 tracks · 123 stages
Difficulty
New labs
Sections 183 articles
Command index 432
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Read the output
$ ss -tln 'sport = :5432' LISTEN 0 200 127.0.0.1:5432 0.0.0.0:* $ psql -h 127.0.0.1 -U shop -d shop -c 'SELECT 1' psql: error: connection to server at "127.0.0.1", port 5432 failed: FATAL: no pg_hba.conf entry for host "127.0.0.1", user "shop", database "shop", no encryption
~/.pgpass