plugin_klish: STRING PTYPE supports regular expressions.

The regular expression can be put to the body of STRING's ACTION tag.
The input value will be validated by regex. If ACTION's body is empty then
any string fits.

plugins/klish/ptype_string.c

@@ -0,0 +1,95 @@
+/*
+ * Implementation of STRING PTYPE.
+ *
+ * It gets any string by default. The regular expression can be defined within
+ * PTYPE body. In this case input string will be validated using this regexp.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <regex.h>
+
+#include <faux/str.h>
+#include <faux/list.h>
+#include <faux/conv.h>
+#include <faux/argv.h>
+#include <klish/kcontext.h>
+#include <klish/kentry.h>
+
+
+typedef struct {
+	bool_t is_regex;
+	regex_t compiled_regex;
+} klish_ptype_STRING_t;
+
+
+static void klish_ptype_STRING_free(void *data)
+{
+	klish_ptype_STRING_t *udata = (klish_ptype_STRING_t *)data;
+
+	if (udata->is_regex)
+		regfree(&udata->compiled_regex);
+
+	faux_free(udata);
+}
+
+
+klish_ptype_STRING_t *klish_ptype_STRING_init(kentry_t *entry,
+	const char *pattern)
+{
+	klish_ptype_STRING_t *udata = NULL;
+
+	udata = faux_malloc(sizeof(*udata));
+	assert(udata);
+	if (!udata)
+		return NULL;
+
+	if (faux_str_is_empty(pattern)) {
+		udata->is_regex = BOOL_FALSE;
+	} else {
+		udata->is_regex = BOOL_TRUE;
+		if (regcomp(&udata->compiled_regex, pattern,
+			REG_NOSUB | REG_EXTENDED))
+		{
+			faux_free(udata);
+			return NULL;
+		}
+	}
+
+	kentry_set_udata(entry, udata, klish_ptype_STRING_free);
+
+	return udata;
+}
+
+/** @brief PTYPE: Arbitrary string
+ */
+int klish_ptype_STRING(kcontext_t *context)
+{
+	kentry_t *entry = NULL;
+	const char *value = NULL;
+	klish_ptype_STRING_t *udata = NULL;
+	size_t len = 0;
+
+	entry = kcontext_candidate_entry(context);
+	value = kcontext_candidate_value(context);
+
+	udata = (klish_ptype_STRING_t *)kentry_udata(entry);
+	if (!udata) {
+		const char *pattern = kcontext_script(context);
+		udata = klish_ptype_STRING_init(entry, pattern);
+		if (!udata)
+			return -1;
+	}
+
+	if (!udata->is_regex)
+		return 0;
+
+	if (regexec(&udata->compiled_regex, value, 0, NULL, 0))
+		return -1;
+
+	return 0;
+}