spark

spark [-h] [numbers...]

spark generates sparkline graphs from a list of numbers, rendering them as Unicode block characters (▁▂▃▄▅▆▇█) in the terminal. Values are mapped proportionally across eight height levels, with the minimum value getting the shortest bar and the maximum the tallest.Numbers can be provided as command-line arguments, piped via stdin, or read from a file. Input supports comma-separated, space-separated, and newline-separated formats, making it easy to integrate with other Unix tools through pipes.The output is plain text using standard Unicode characters, so it works in any terminal that supports Unicode. Sparklines are useful for visualizing trends in data at a glance without requiring a full graphing tool.

Terminal must support Unicode. Limited resolution (8 levels). No axes or labels. Written as a bash shell script with no dependencies beyond bash.

spark was created by Zach Holman as a simple bash script for command-line data visualization. The concept inspired many alternative implementations in Ruby, Python, Haskell, Java, and other languages.

gnuplot(1), termgraph(1)