Bash 5.1 Features and Improvements

Released in December 2020, Bash 5.1 introduced several notable features and improvements for modern shell scripting.

New Shell Variables

EPOCHSECONDS and EPOCHREALTIME

Two new special variables for accessing current time:

# Get current Unix timestamp in seconds
echo "Current timestamp: ${EPOCHSECONDS}"

# Get current Unix timestamp with microsecond precision
echo "High precision timestamp: ${EPOCHREALTIME}"

# Practical example: Simple benchmarking
start="${EPOCHREALTIME}"