man ngs-js (Commandes) - interpret, execute, and compile JavaScript files

NAME

js - interpret, execute, and compile JavaScript files

SYNOPSIS

js [-acfghlNStvV] [-d type] [-e code] [-O[level]] [-r option] [-s size] [-W option] file [argument]...

DESCRIPTION

The js program is the JavaScript interpreter command. It can be used to execute JavaScript and JavaScript byte-code files. The progam can also be used to compile JavaScript files into the byte-code files.

OPTIONS

-a, --annotate-assembler
Annotate the created assembler listing with the original JavaScript source code. The option can be used only with the --assembler option.
-c, --compile
Compile JavaScript files to byte-code. The generated byte-code is saved to file which name is created from the name of the input file by replacing the suffix .js with the suffix .jsc. The compilation can be controlled with options --debug, --optimize, and --compiler-option.
-d type, --dispatch=type
Use the byte-code instruction dispatch method type. The current implementation supports the following dispatch methods:
switch-basic
The basic switch-method using a big switch-case table to dispatch the instruction. This method is available only if the interpreter has been configured with the option --with-all-dispatchers.
switch
An optimized version of the switch-method. This method is supported on all environments.
jumps
The fastest dispatch method that uses the `computed goto' statement of the GNU C-compiler. This method is available if the interpreter has been compiled with the GNU C-compiler. The default dispatch method, for environments that has the GNU C-compiler, is jumps. For all other environments, the default method is switch.
-e code, --eval=code
Evaluate JavaScript code code.
-f, --file
Stop processing options and use the next argument as the name of the JavaScript (or byte-code) file. All the remaining arguments are passed to the interpreter through the ARGS array. The first item of the array will be the name of the script, i.e. the argument that follows the option --file.
-g, --debug
Make the compiler to generate debugging information to the generated byte-code files. This option can be used with the option --compile.
-h, --help
Print a short help message that describes the options that can be given to the js program.
-l, --load
Load multiple JavaScript and JavaScript byte-code files to the interpreter. Normally, the first non-option argument is evaluated and all remaining arguments are passed to the script as arguments. With the option --load, multiple files can be loaded the to the interpreter. The loading can be stopped with option --file that specifies the last file to load.
-N, --no-compiler
Do not define the compiler to the virtual machine. This option makes the interpreter smaller, but the interpreter can only execute pre-compiled byte-code files. The option disables the eval global method.
-O [level], --optimize[=level]
Set the compiler optimization level to level. The compiler has three different optimization levels:
0
Do not optimize.
1
Perform all cheap optimizations which do not required heavy assembler instruction analyzing.
2
Perform all optimizations, supported by the compiler. The default optimization level is 1.
-r option, --secure=option
Turn on virtual machine security option option. The following security options are available:
file
Disable insecure methods from the buit-in File object.
system
Disable insecure methods from the buit-in System object.
-s size, --stack-size=size
Set the size of the virtual machine operand stack to size. The size of the virtual machine operand stack is set at the startup-time and it can't be enlarged dynamically at the runtime.
-S, --assembler
Compile JavaScript files to JavaScript assembler. The generated assembler listing is saved to file which name is created from the name of the input file by replacing the suffix .js with the suffix .jas. The compilation can be controlled with options --optimize, and --compiler-option.
-t, --stacktrace
Print a stack trace on error. When an error occurs during the evaluation of a script, the virtual machine will halt and the js program terminates. If the option --stacktrace was given to the interpreter, the virtual machine will print a stack trace that shows the call stack at the point of the error.
-v, --verbose
Increase the verbosity of the interpreter. The option can be given multiple times to increase the amount of messages the interpreter prints.
-V, --version
Print the version number of the js program.
-W option, --compiler-option=option
Set JavaScript compiler options according to the option specification option. The specification option can be given in two forms. In the normal form, the option specifies a compiler option that should be set on. If the specification @var{option} starts with the prefix `no-', the specified option will be turn off. The following option specifications are currently implemented:
all
match most of the compile time options
pedantic
match all compile time options. This option generates as much warnings as possible. It will also complain about some things that are allowed by the ECMAScript standard, but which are consired to show bad programming style, for example, missing semicolons.
runtime
match all runtime options
shadow
warn if a variable declaration shadows a parameter
undefined
runtime check for undefined global variables
unused-argument
warn about unused arguments
unused-variable
warn about unused local variables
with-clobber
warn if the with-lookup of a symbol is clobbered because the symbol is defined to be a local variable or a function argument
missing-semicolon
warn about missing semicolons that are fixed by the missing semicolon inserting during the compilation
strict-ecma
warn about things that are supported by this implementation, but are not allowed by the ECMAScript standard. These features are:
- line terminators in string and regular expression constant
deprecated
warn if deprecated features has been used in the source code
-x, --executable
Add execute permissions to the generated byte-code files. This option is useful on Linux environments where JavaScript byte-code files can be executed natively with the `binfmt_js' module.

AUTHOR

Markku Rossi <mtr@ngs.fi>

NGS JavaScript WWW home page: <http://www.ngs.fi/js/>

SEE ALSO