Method replaceParameters

src/org/apache/pig/scripting/Pig.java:299–320

Replaces the $ with their actual values @param qstr the pig script to rewrite @param vars parameters and their values @return the modified version

(String qstr, Map<String, Object> vars)

     * @return the modified version
     */
    private String replaceParameters(String qstr, Map<String, Object> vars)
            throws IOException {

        List<String> params = new ArrayList<String>();
        for (Entry<String, Object> entry : vars.entrySet()) {
            params.add(entry.getKey() + "="
                    + fixNonEscapedDollarSign(entry.getValue().toString()));
        }

        PigContext context = getScriptContext().getPigContext();
        List<String> contextParams = context.getParams();
        if (contextParams != null) {
            for (String param : contextParams) {
                params.add(param);
            }
        }

        BufferedReader reader = new BufferedReader(new StringReader(qstr));
        String substituted =  context.doParamSubstitution(reader, params, context.getParamFiles());
        context.setParams(contextParams); // reset params that were originally in PigContext
        return substituted;
    }

    // Escape the $ so that we can use the parameter substitution
    // to perform bind operation. Parameter substitution will un-escape $