dlvhex - script plugin (0.1.0)
enables dlvhex to use scripts for generating atoms and
to rewrite whole input programs using a script before processing them
* Requirements:
- dlvhex (version >= 1.4)
- (optional) dlvhex-stringplugin (just needed for the tests and examples)
* Installation:
- ./configure
(use switch --enable-userinstall to install plugin into home directory)
- make install
* Testing:
- make check
- you can also run 'make all' in dlvhex-scriptplugin-0.1.0/examples/demos/
* Usage:
- script-atom:
The plugin provides a single atom:
&script[COMMAND_STRING](OUTPUT)
COMMAND_STRING is the command to be executed
OUTPUT is line-wise
The output of the atom is the set of lines that is returned from the
call of the command-string. The resulting atoms are all single-tuples.
The data-type of a tuple (number:without quotes; string:with quotes)
depends on the resulting line (contains only digits?).
- script-converter:
In order to specify a script for converting the input, the following
command-line flag hast to be passed to dlvhex.
--convert=SCRIPT
SCRIPT is the script that converts the input file before passing it
back to dlvhex.
The plugin calls your script with a file, containing the input, as the
first argument. This means that you have to read the content of the
file that you get as the first argument. After processing the
file-content you can pass the modified dlvhex-input back to dlvhex by
printing it out to STDOUT.
Notes: - you can use *.sh, *.awk, *.py, *.pl,... as scripts
- Every script you want to use within the script-atom or the
script-converter has to be exutable (permissions!).
(You can set the permission by using: chmod +x script.file)
- To use a script directly, without having to specify its path,
you have to add its directory to the $PATH variable.
(you can set the path-variable with: PATH=$PATH:/dir/to/script/)
- Use so-called shebangs to specify in the script with which
interpreter it is meant to be called.
http://en.wikipedia.org/wiki/Shebang_(Unix)
- The output of a script, terminating with an error, will be
ignored.