diff --git a/amend/execute.c b/amend/execute.c
new file mode 100644
index 0000000..9162ad6
--- /dev/null
+++ b/amend/execute.c
@@ -0,0 +1,315 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#undef NDEBUG
+#include <assert.h>
+#include "ast.h"
+#include "execute.h"
+
+typedef struct {
+    int c;
+    const char **v;
+} StringList;
+
+static int execBooleanValue(ExecContext *ctx,
+        const AmBooleanValue *booleanValue, bool *result);
+static int execStringValue(ExecContext *ctx, const AmStringValue *stringValue,
+        const char **result);
+
+static int
+execBooleanExpression(ExecContext *ctx,
+        const AmBooleanExpression *booleanExpression, bool *result)
+{
+    int ret;
+    bool arg1, arg2;
+    bool unary;
+
+    assert(ctx != NULL);
+    assert(booleanExpression != NULL);
+    assert(result != NULL);
+    if (ctx == NULL || booleanExpression == NULL || result == NULL) {
+        return -__LINE__;
+    }
+
+    if (booleanExpression->op == AM_BOP_NOT) {
+        unary = true;
+    } else {
+        unary = false;
+    }
+
+    ret = execBooleanValue(ctx, booleanExpression->arg1, &arg1);
+    if (ret != 0) return ret;
+
+    if (!unary) {
+        ret = execBooleanValue(ctx, booleanExpression->arg2, &arg2);
+        if (ret != 0) return ret;
+    } else {
+        arg2 = false;
+    }
+
+    switch (booleanExpression->op) {
+    case AM_BOP_NOT:
+        *result = !arg1;
+        break;
+    case AM_BOP_EQ:
+        *result = (arg1 == arg2);
+        break;
+    case AM_BOP_NE:
+        *result = (arg1 != arg2);
+        break;
+    case AM_BOP_AND:
+        *result = (arg1 && arg2);
+        break;
+    case AM_BOP_OR:
+        *result = (arg1 || arg2);
+        break;
+    default:
+        return -__LINE__;
+    }
+
+    return 0;
+}
+
+static int
+execFunctionArguments(ExecContext *ctx,
+        const AmFunctionArguments *functionArguments, StringList *result)
+{
+    int ret;
+
+    assert(ctx != NULL);
+    assert(functionArguments != NULL);
+    assert(result != NULL);
+    if (ctx == NULL || functionArguments == NULL || result == NULL) {
+        return -__LINE__;
+    }
+
+    result->c = functionArguments->argc;
+    result->v = (const char **)malloc(result->c * sizeof(const char *));
+    if (result->v == NULL) {
+        result->c = 0;
+        return -__LINE__;
+    }
+
+    int i;
+    for (i = 0; i < functionArguments->argc; i++) {
+        ret = execStringValue(ctx, &functionArguments->argv[i], &result->v[i]);
+        if (ret != 0) {
+            result->c = 0;
+            free(result->v);
+            //TODO: free the individual args, if we're responsible for them.
+            result->v = NULL;
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
+static int
+execFunctionCall(ExecContext *ctx, const AmFunctionCall *functionCall,
+        const char **result)
+{
+    int ret;
+
+    assert(ctx != NULL);
+    assert(functionCall != NULL);
+    assert(result != NULL);
+    if (ctx == NULL || functionCall == NULL || result == NULL) {
+        return -__LINE__;
+    }
+
+    StringList args;
+    ret = execFunctionArguments(ctx, functionCall->args, &args);
+    if (ret != 0) {
+        return ret;
+    }
+
+    ret = callFunction(functionCall->fn, args.c, args.v, (char **)result, NULL);
+    if (ret != 0) {
+        return ret;
+    }
+
+    //TODO: clean up args
+
+    return 0;
+}
+
+static int
+execStringValue(ExecContext *ctx, const AmStringValue *stringValue,
+        const char **result)
+{
+    int ret;
+
+    assert(ctx != NULL);
+    assert(stringValue != NULL);
+    assert(result != NULL);
+    if (ctx == NULL || stringValue == NULL || result == NULL) {
+        return -__LINE__;
+    }
+
+    switch (stringValue->type) {
+    case AM_SVAL_LITERAL:
+        *result = strdup(stringValue->u.literal);
+        break;
+    case AM_SVAL_FUNCTION:
+        ret = execFunctionCall(ctx, stringValue->u.function, result);
+        if (ret != 0) {
+            return ret;
+        }
+        break;
+    default:
+        return -__LINE__;
+    }
+
+    return 0;
+}
+
+static int
+execStringComparisonExpression(ExecContext *ctx,
+        const AmStringComparisonExpression *stringComparisonExpression,
+        bool *result)
+{
+    int ret;
+
+    assert(ctx != NULL);
+    assert(stringComparisonExpression != NULL);
+    assert(result != NULL);
+    if (ctx == NULL || stringComparisonExpression == NULL || result == NULL) {
+        return -__LINE__;
+    }
+
+    const char *arg1, *arg2;
+    ret = execStringValue(ctx, stringComparisonExpression->arg1, &arg1);
+    if (ret != 0) {
+        return ret;
+    }
+    ret = execStringValue(ctx, stringComparisonExpression->arg2, &arg2);
+    if (ret != 0) {
+        return ret;
+    }
+
+    int cmp = strcmp(arg1, arg2);
+
+    switch (stringComparisonExpression->op) {
+    case AM_SOP_LT:
+        *result = (cmp < 0);
+        break;
+    case AM_SOP_LE:
+        *result = (cmp <= 0);
+        break;
+    case AM_SOP_GT:
+        *result = (cmp > 0);
+        break;
+    case AM_SOP_GE:
+        *result = (cmp >= 0);
+        break;
+    case AM_SOP_EQ:
+        *result = (cmp == 0);
+        break;
+    case AM_SOP_NE:
+        *result = (cmp != 0);
+        break;
+    default:
+        return -__LINE__;
+        break;
+    }
+
+    return 0;
+}
+
+static int
+execBooleanValue(ExecContext *ctx, const AmBooleanValue *booleanValue,
+        bool *result)
+{
+    int ret;
+
+    assert(ctx != NULL);
+    assert(booleanValue != NULL);
+    assert(result != NULL);
+    if (ctx == NULL || booleanValue == NULL || result == NULL) {
+        return -__LINE__;
+    }
+
+    switch (booleanValue->type) {
+    case AM_BVAL_EXPRESSION:
+        ret = execBooleanExpression(ctx, &booleanValue->u.expression, result);
+        break;
+    case AM_BVAL_STRING_COMPARISON:
+        ret = execStringComparisonExpression(ctx,
+                &booleanValue->u.stringComparison, result);
+        break;
+    default:
+        ret = -__LINE__;
+        break;
+    }
+
+    return ret;
+}
+
+static int
+execCommand(ExecContext *ctx, const AmCommand *command)
+{
+    int ret;
+
+    assert(ctx != NULL);
+    assert(command != NULL);
+    if (ctx == NULL || command == NULL) {
+        return -__LINE__;
+    }
+
+    CommandArgumentType argType;
+    argType = getCommandArgumentType(command->cmd);
+    switch (argType) {
+    case CMD_ARGS_BOOLEAN:
+        {
+            bool bVal;
+            ret = execBooleanValue(ctx, command->args->u.b, &bVal);
+            if (ret == 0) {
+                ret = callBooleanCommand(command->cmd, bVal);
+            }
+        }
+        break;
+    case CMD_ARGS_WORDS:
+        {
+            AmWordList *words = command->args->u.w;
+            ret = callCommand(command->cmd, words->argc, words->argv);
+        }
+        break;
+    default:
+        ret = -__LINE__;
+        break;
+    }
+
+    return ret;
+}
+
+int
+execCommandList(ExecContext *ctx, const AmCommandList *commandList)
+{
+    int i;
+    for (i = 0; i < commandList->commandCount; i++) {
+        int ret = execCommand(ctx, commandList->commands[i]);
+        if (ret != 0) {
+            int line = commandList->commands[i]->line;
+            return line > 0 ? line : ret;
+        }
+    }
+
+    return 0;
+}