Show HAProxy version and build features
Build a paste-ready command, then review its compatibility and effects before running it.
haproxy -vv | head -20read-onlyno known side effects Compatibility
LinuxVerified for Linux using posix, bash, zsh syntax.
Operational knowledgereview due 2027-01-20
Requirementshaproxyhaproxy must be installed and available on PATH.
Version supporthaproxy Current supported releasesVerified for linux using posix, bash, zsh syntax; consult compatibility notes for platform-specific differences.
Expected signalsHAProxy version 3.2.1Representative successful output; values vary with the selected target and system state.
Known errorshaproxy: command not foundhaproxy is missing or is not available on PATH.
Verifyhaproxy -vv | head -20The output matches the expected target and exits without an error.Rollback noteNot required: this command is read-only and does not change system state.
Command breakdown
01haproxyCommandRuns the haproxy stage of this one-liner.
02-vvOptionConfigures haproxy with the -vv option.
03|PipelinePasses the output on the left to the command on the right.
04headCommandRuns the head stage of this one-liner.
05-20OptionConfigures head with the -20 option.
Example input
haproxy -vv | head -20
Example output
HAProxy version 3.2.1
Status: long-term supported branch
Running on: Linux 6.14.0 x86_64
Feature list : +EPOLL +OPENSSL +LUA +PROMEX
Illustrative output — exact values vary by system and data.
Official sources