diff --git a/src/main/java/org/cobbzilla/util/main/FileHeader.java b/src/main/java/org/cobbzilla/util/main/FileHeader.java
new file mode 100644
index 0000000..25c4f67
--- /dev/null
+++ b/src/main/java/org/cobbzilla/util/main/FileHeader.java
@@ -0,0 +1,16 @@
+package org.cobbzilla.util.main;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.regex.Pattern;
+
+public class FileHeader {
+
+    @Getter @Setter private String ext;
+    @Getter @Setter private String header;
+    @Getter @Setter private String regex;
+
+    @Getter(lazy=true) private final Pattern pattern = Pattern.compile(getRegex(), Pattern.MULTILINE);
+
+}
diff --git a/src/main/java/org/cobbzilla/util/main/FileHeaderMain.java b/src/main/java/org/cobbzilla/util/main/FileHeaderMain.java
new file mode 100644
index 0000000..3f98774
--- /dev/null
+++ b/src/main/java/org/cobbzilla/util/main/FileHeaderMain.java
@@ -0,0 +1,41 @@
+package org.cobbzilla.util.main;
+
+import org.cobbzilla.util.io.FileUtil;
+import org.cobbzilla.util.io.FilesystemWalker;
+
+import java.util.Map;
+import java.util.regex.Matcher;
+
+import static org.cobbzilla.util.io.FileUtil.toFileOrDie;
+import static org.cobbzilla.util.io.FileUtil.toStringOrDie;
+
+public class FileHeaderMain extends BaseMain<FileHeaderOptions> {
+
+    public static void main (String[] args) { main(FileHeaderMain.class, args); }
+
+    @Override protected void run() throws Exception {
+        final FileHeaderOptions opts = getOptions();
+        final Map<String, FileHeader> headers = opts.getHeaders();
+        new FilesystemWalker()
+                .withDir(opts.getDir())
+                .withVisitor(file -> {
+                    final String ext = FileUtil.extension(file);
+                    if (ext.startsWith(".")) {
+                        final FileHeader header = headers.get(ext.substring(1));
+                        if (header != null) {
+                            String contents = toStringOrDie(file);
+                            if (contents == null) contents = "";
+                            final Matcher matcher = header.getPattern().matcher(contents);
+                            if (matcher.find()) {
+                                contents = contents.substring(0, matcher.start())
+                                        + header.getHeader() + "\n" + contents.substring(matcher.end());
+                            } else {
+                                contents = header.getHeader() + "\n" + contents;
+                            }
+                            toFileOrDie(file, contents);
+                        }
+                    }
+                }).walk();
+    }
+
+}
diff --git a/src/main/java/org/cobbzilla/util/main/FileHeaderOptions.java b/src/main/java/org/cobbzilla/util/main/FileHeaderOptions.java
new file mode 100644
index 0000000..3f95845
--- /dev/null
+++ b/src/main/java/org/cobbzilla/util/main/FileHeaderOptions.java
@@ -0,0 +1,44 @@
+package org.cobbzilla.util.main;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.apache.commons.io.IOUtils;
+import org.kohsuke.args4j.Option;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Arrays;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import static java.util.function.Function.identity;
+import static org.cobbzilla.util.json.JsonUtil.json;
+import static org.cobbzilla.util.string.StringUtil.UTF8cs;
+
+public class FileHeaderOptions extends BaseMainOptions {
+
+    public static final String USAGE_DIR = "Directory to process";
+    public static final String OPT_DIR = "-d";
+    public static final String LONGOPT_DIR = "--dir";
+    @Option(name=OPT_DIR, aliases=LONGOPT_DIR, usage=USAGE_DIR, required=true)
+    @Getter @Setter private File dir;
+
+    public static final String USAGE_HEADERS_JSON = "JSON file with header info, or - to read from stdin";
+    public static final String OPT_HEADERS_JSON = "-H";
+    public static final String LONGOPT_HEADERS_JSON = "--headers";
+    @Option(name=OPT_HEADERS_JSON, aliases=LONGOPT_HEADERS_JSON, usage=USAGE_HEADERS_JSON, required=true)
+    @Getter @Setter private String headersJson;
+
+    public Map<String, FileHeader> getHeaders() throws IOException {
+        final InputStream input;
+        if (headersJson.equals("-")) {
+            input = inStream(null);
+        } else {
+            input = inStream(new File(headersJson));
+        }
+        final FileHeader[] headers = json(IOUtils.toString(input, UTF8cs), FileHeader[].class);
+        return Arrays.stream(headers).collect(Collectors.toMap(FileHeader::getExt, identity()));
+    }
+
+}