return NULL;

}

/*

* Variables (and user-defined functions)

*/

static LIST_HEAD(variable_list);

struct variable {

char *name;

char *value;

struct list_head node;

};

static struct variable *variable_lookup(const char *name)

{

struct variable *v;

list_for_each_entry(v, &variable_list, node) {

if (!strcmp(name, v->name))

return v;

}

return NULL;

}

static char *variable_expand(const char *name, int argc, char *argv[])

{

struct variable *v;

v = variable_lookup(name);

if (!v)

return NULL;

return expand_string_with_args(v->value, argc, argv);

}

void variable_add(const char *name, const char *value)

{

struct variable *v;

v = variable_lookup(name);

if (v) {

free(v->value);

} else {

v = xmalloc(sizeof(*v));

v->name = xstrdup(name);

list_add_tail(&v->node, &variable_list);

}

v->value = xstrdup(value);

}

static void variable_del(struct variable *v)

{

list_del(&v->node);

free(v->name);

free(v->value);

free(v);

}

void variable_all_del(void)

{

struct variable *v, *tmp;

list_for_each_entry_safe(v, tmp, &variable_list, node)

variable_del(v);

}

/*

* Evaluate a clause with arguments. argc/argv are arguments from the upper

* function call.

*/

static char *eval_clause(const char *str, size_t len, int argc, char *argv[])

{

char *tmp, *name, *res, *prev, *p;

char *tmp, *name, *res, *endptr, *prev, *p;

int new_argc = 0;

char *new_argv[FUNCTION_MAX_ARGS];

int nest = 0;

int i;

unsigned long n;

tmp = xstrndup(str, len);

/*

* If variable name is '1', '2', etc. It is generally an argument

* from a user-function call (i.e. local-scope variable). If not

* available, then look-up global-scope variables.

*/

n = strtoul(tmp, &endptr, 10);

if (!*endptr && n > 0 && n <= argc) {

res = xstrdup(argv[n - 1]);

goto free_tmp;

}

prev = p = tmp;

/*

new_argv[i] = expand_string_with_args(new_argv[i + 1],

argc, argv);

/* Search for variables */

res = variable_expand(name, new_argc, new_argv);

if (res)

goto free;

/* Look for built-in functions */

res = function_expand(name, new_argc, new_argv);

if (res)

for (i = 0; i < new_argc; i++)

free(new_argv[i]);

free(name);

free_tmp:

free(tmp);

return res;