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package org.scijava.script.process;

import org.scijava.log.LogService;
import org.scijava.plugin.Parameter;
import org.scijava.plugin.Plugin;
import org.scijava.script.ScriptInfo;
import org.scijava.script.ScriptLanguage;
import org.scijava.script.ScriptService;

/**
 * A {@link ScriptProcessor} which looks for a {@code #!} at the beginning of a
 * script, and set the language accordingly.
 * 
 * @author Curtis Rueden
 */
@Plugin(type = ScriptProcessor.class)
public class ShebangScriptProcessor implements ScriptProcessor {

	@Parameter
	private ScriptService scriptService;

	@Parameter
	private LogService log;

	private ScriptInfo info;
	private boolean first = true;

	// -- ScriptProcessor methods --

	@Override
	public void begin(final ScriptInfo scriptInfo) {
		info = scriptInfo;
	}

	@Override
	public void process(final String line) {
		if (!first) return;
		if (line.startsWith("#!")) {
			// shebang!
			final String langName = line.substring(2);
			final ScriptLanguage lang = scriptService.getLanguageByName(langName);
			if (lang != null) info.setLanguage(lang);
			else log.warn("Unknown script language: " + langName);
		}
		first = false;
	}
}
Add script processor for shebang syntax
Add script processor for shebang syntax

This lets a script declare its own intended language.

See:
https://github.com/hadim/scijava-jupyter-kernel/issues/51#issuecomment-301816226
