Choose Between -R and -r for ANSI Color Rendering in less

Goal

To view log files containing ANSI SGR color codes with a pager that preserves color while protecting the terminal from unintended control sequences.

Constraints & Uncertainty

The less pager offers two options: -R (RAW‑CONTROL‑CHARS) which passes ANSI SGR sequences but filters other control characters, and -r (raw‑control‑chars) which passes all control characters, including potentially destructive ones. The current behavior requires users to choose manually and offers no automatic detection of ANSI color output. This leaves consistency across invocations uncertain and may expose terminals to corruption if -r is used inadvertently.

Unresolved Questions

• Should less automatically detect the presence of ANSI SGR codes and default to -R for color-producing commands?
• What fallback mechanism could be provided when -r is chosen to mitigate terminal corruption?
• Under what test conditions (e.g., mixed SGR and bell characters) would a default change be validated as safe?