Page

bl eval

Evaluate a JavaScript expression (optionally navigate to URL first)

Evaluate a JavaScript expression (optionally navigate to URL first)

Usage

bl eval [args...] [OPTIONS]

Arguments

ArgumentDescription
[args...][url] expression — JS to evaluate, optionally preceded by a URL to navigate first

Options

OptionDescription
--stdinRead expression from stdin
--headlessHide browser window (visible by default)
--jsonOutput as JSON
--session <value>Run this command in the named session (env: BL_SESSION; default: "default")

Global options

OptionDescription
-v, --verboseEnable debug logging

Examples

bl eval "document.title"
# Evaluates on current page

bl eval https://example.com "document.title"
# Navigates to URL first, then evaluates

bl eval --stdin
# Read expression from stdin, e.g. echo 'document.title' | ... (avoids shell quoting issues)

On this page