JSC

jsc is a command-line utility that allows you to run JavaScript programs outside of the context of a web browser. It is primarily used as part of the test harness for validating the JavaScript portions of WebKit, but can also be used as a scripting tool.

jsc can be run in an interactive mode to test out JavaScript expressions, or it can be passed one or more files to run similar to invoking a Perl or Python script.

Usage

Command Line Flags

Usage: jsc [options] [files] [-- arguments]  -d         Dumps bytecode (debug builds only)  -e         Evaluate argument as script code  -f         Specifies a source file (deprecated)  -h|--help  Prints this help message  -i         Enables interactive mode (default if no files are specified)  -s         Installs signal handlers that exit on a crash (Unix platforms only)  -p <file>  Outputs profiling data to a file  -x         Output exit code before terminating  --options                  Dumps all JSC VM options and exits  --dumpOptions              Dumps all JSC VM options before continuing  --<jsc VM option>=<value>  Sets the specified JSC VM option

Built-In Functions

checkSyntax('[FileName]')

Check the syntax of the specified external JavaScript file[FileName].

debug(term)

Prints a human-readable version of the passed argument.

gc()

Perform a garbage collection. It will returnundefined.

load('[FileName]')

Load and execute the specified external JavaScript file[FileName]. If the run is successful, it will return the final value of the script.

quit()

Quit the interpreter

readline()

Read data from stdin. Mainly useful for writing test routines.

run('[FileName]')

Load and execute the specified external JavaScript file[FileName]. If the run is successful, it will return the elapsed milliseconds for the run.

version()

Currently does nothing. It will returnundefined.

Examples

You can usejsc as a calculator:

$ ./jsc> "hello"hello> 1 + 34> 2 * Math.sin(32)1.1028533624833812> 2 * Math.floor(1.2)2> 2 * Math.ceil(1.2)4> 15.3 / 18 * 27.1 * (Math.ceil(1.3) * Math.exp(2.3) * Math.log (1.223) * Math.sin(32.22))66.6192983328985> quit()

You can also test more complicated expressions:

> var add3 = function(arg) { return arg + 3; }undefined> add3(3)6> var foo = readline();abcdefgundefined> fooabcdefg> quit()

The return value ofundefined from the variable assignment is from the JavaScript specification. While it might seem like an odd response to a successful operation, it is the expected behavior.