agordon/webawk

AWK in Javascript

WebAWK - AWK in Javascript

This is an adaptation of the AWK programming language running entirely in Javascript, on the client-side web-browse (or on node.js).

NOTE This is not a re-implementation of AWK in Javascript. The C source code of Busybox AWK was compiled (slightly modified) using emscripten (a LLVM-to-Javascript compiler).

Using WebAWK

Online demo: http://agordon.github.com/webawk/ Interactive AWK demo (requires a recent web-browser): http://agordon.github.com/webawk/awk_web_worker.html

Try locally:

# download the code.
$ git clone git://github.com/agordon/webawk.git
$ cd webawk

# use the supplied pre-built javascripts, to save time and effort.
$ make prebuilt

# test the node.js version
# (need to have "node" installed, obviously)
$ make node-test

# test the web version
# (this will print the URL of the file you'll need to open in your browser)
$ make web-test

# or build the javascripts, by compiling the C code.
# see compilation instructions below.
$ make node
$ make web

# To debug / add features, compile for a native binary
$ make bin
$ make bin-test

Re-building the Javascript code

To rebuild the javascript code, you'll need the clang and the emscripten compilers. Follow the (emscripten Tutorial for installation and testing instructions.

node.js version

• To compile the node.js version, run make node .
• The node.js version is configured to start immediately (i.e. calling AWK's main() function).
• The fcompiled output file is awk_node.js, and using it with node should be equivalent to running awk on the command line (note: equivalent to the old oawk, not GNU awk).
• Try the following (which are equivalent to make node-test):

       $ node awk_node.js 'BEGIN { print "Hello Node Awk World" ; exit }'
       vs.
       $ awk 'BEGIN { print "Hello Awk World" ; exit }'

	or

       $ node awk_node.js -f tests/my_program.awk tests/my_input.txt
       vs
       $ awk -f tests/my_program.awk tests/my_input.txt

       # Technical note:
       # the node version doesn't read the input files from 'tests' -
       # the files are embedded in the javascript during compilation
       # (so don't expect to change them and see the results)

web version

• To compile the web version, run make web .
• The compiled output file is website/awk_web.js. It contains the emscripten'd AWK code, wrapped in a single javascript function run_web_awk() .
• Load the file websize/awk_web.js in your web-browser to run sample AWK programs.
• The web version is configured with additional wrappers, and a friendly javascript function that runs awk on a given input. The source code for the wrappers is in js_emsc sub-directory.
• See tests/web_test.js for an example of calling this function.

Compilation Warnings

Some warnings and error messages are expected when compiling with emscripten.

Warnings similar to these can be ignored:

In file included from heirloom_emsc/libuxre/onefile.c:33:
heirloom_emsc/libuxre/bracket.c:801:14: warning: array index of '1' indexes past the end of an array (that contains 1 element)
      [-Warray-bounds]
                mcbuf.wc = mcbuf.cep->weight[1];
                           ^                 ~
heirloom_emsc/libuxre/colldata.h:163:2: note: array 'weight' declared here
        wuchar_type     weight[COLL_WEIGHTS_MAX];
        ^
In file included from heirloom_emsc/libuxre/onefile.c:37:
heirloom_emsc/libuxre/regcomp.c:55:23: warning: '&&' within '||' [-Wlogical-op-parentheses]
        if (ep->re_nsub != 0 && (flags & (REG_NOSUB | REG_ONESUB)) == 0
            ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
heirloom_emsc/libuxre/regcomp.c:55:23: note: place parentheses around the '&&' expression to silence this warning
        if (ep->re_nsub != 0 && (flags & (REG_NOSUB | REG_ONESUB)) == 0
                             ^

Also, the following unresolved symbols are expected:

Warning: Unresolved symbol: _llvm_va_start
Warning: Unresolved symbol: _llvm_dbg_declare
Warning: Unresolved symbol: _llvm_expect_i32

However, if you get compilation errors, or other unresolved symbols - that's a likely problem that might prevent AWK from functioning.

Compiling the AWK binary

• To compile the binry version, run make bin (you'll need the clang compiler).
• The compiled output file is awk_bin.
• This file can be easily debugged with gdb (or similar debuggers).

BusyBox AWK

This awk implementation is based (=copied) from Busybox's AWK implementation, written by Dmitry Zakharov dmit@crp.bank.gov.ua. It also uses many of the libbb functions.

Website: http://www.busybox.net/

The code is based on Busybox version 1.20.2 .

To see the changes, run:

$ git clone git://github.com/agordon/webawk.git
$ wget http://www.busybox.net/downloads/busybox-1.20.2.tar.bz2
$ tar -xjf busybox-1.20.2.tar.bz2
$ diff -rup busybox-1.20.2/ weback/busybox

NEWLIB

This implementation uses the Posix Regular Expression code and the getopt() functions from RedHat's newlib.

Website: http://sourceware.org/newlib/

The code is based on Newlib 1.20.0 .

To see the changes, run:

$ git clone git://github.com/agordon/webawk.git
$ wget ftp://sources.redhat.com/pub/newlib/newlib-1.20.0.tar.gz
$ tar -xzf newline-1.20.0.tar.gz
$ diff -rup newlib-1.20.0/newlib webawk/newlib

HACKING

See the HACKING file for more details.

Contact

email: gordon at cshl dot edu source: https://github.com/agordon/webawk.git

License

• The newlib getopt code is public domain.
• The newlib Regex code is BSD.
• The busybox code is GPLv2.
• All other files are BSD.