1 files changed, 142 insertions, 0 deletions
diff --git a/src/uconfig.c b/src/uconfig.c
new file mode 100644
index 0000000..431f76a
--- /dev/null
+++ b/src/uconfig.c
@@ -0,0 +1,142 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "uconfig.h"
+
+struct uconfig_pair_s {
+	char *key;
+	char *value;
+	struct uconfig_pair_s *next;
+};
+
+struct uconfig_s {
+	struct uconfig_pair_s *head;
+	struct uconfig_pair_s *tail;
+};
+
+static struct uconfig_pair_s *uconfig_pair_new(char *line, int sep_idx)
+{
+	assert(line[sep_idx] == '=');
+	line[sep_idx] = '\0';
+	struct uconfig_pair_s *pair = malloc(sizeof(struct uconfig_pair_s));
+	pair->key   = strdup(line);
+	pair->value = strdup(line + sep_idx + 1);
+	pair->next = NULL;
+	return pair;
+}
+
+static void uconfig_add_tail(struct uconfig_s *uconfig,
+			     struct uconfig_pair_s *pair)
+{
+	if (!uconfig->head) {
+		/* first pair in the config handle */
+		uconfig->head = pair;
+		uconfig->tail = pair;
+	}
+	else {
+		uconfig->tail->next = pair;
+		uconfig->tail = pair;
+	}
+}
+
+static int uconfig_parse_line(struct uconfig_s *uconfig,
+			       const char *file,
+			       int line_number,
+			       char *line,
+			       ssize_t line_len)
+{
+	/* Remove trailing newline, if any */
+	if (line[line_len - 1] == '\n') {
+		line[line_len - 1] = '\0';
+		line_len--;
+	}
+
+	/* Find index of '=' character in the line */
+	int sep_idx = 0;
+	while ((sep_idx < line_len) && (line[sep_idx] != '=')) {
+		sep_idx++;
+	}
+	if (sep_idx == line_len) {
+		fprintf(stderr,
+			"%s: %s:%d: no '=' character found\n",
+			__func__, file, line_number);
+		return -1;
+	}
+
+	struct uconfig_pair_s *pair = uconfig_pair_new(line, sep_idx);
+	uconfig_add_tail(uconfig, pair);
+	return 0;
+}
+
+struct uconfig_s *uconfig_new(const char*file)
+{
+	FILE *input = fopen(file, "r");
+	struct uconfig_s *uconfig = NULL;
+	ssize_t line_len;
+	size_t line_size = 128;
+	char *line = NULL;
+	int line_number = 1;
+	int rc;
+
+	if (input == NULL) {
+		fprintf(stderr, "%s: fopen: %s: ", __func__, file);
+		perror("");
+		goto err;
+	}
+
+	uconfig = calloc(1, sizeof(struct uconfig_s));
+	line = malloc(line_size);
+
+	while ((line_len = getline(&line, &line_size, input)) != -1) {
+		rc = uconfig_parse_line(uconfig, file, line_number, line, line_len);
+		if (rc == -1)
+			goto err;
+		line_number++;
+	}
+
+	if (ferror(input)) {
+		fprintf(stderr, "%s: getline: %s: ", __func__, file);
+		perror("");
+		goto err;
+	}
+
+	free(line);
+	fclose(input);
+	return uconfig;
+
+err:
+	if (input)
+		fclose(input);
+	if (line)
+		free(line);
+	if (uconfig)
+		uconfig_destroy(uconfig);
+	return NULL;
+}
+
+const char *uconfig_get(const struct uconfig_s *uconfig, const char *key)
+{
+	struct uconfig_pair_s *pair = uconfig->head;
+	while (pair) {
+		if (strcmp(pair->key, key) == 0)
+			return pair->value;
+		pair = pair->next;
+	}
+	return NULL;
+}
+
+static void uconfig_destroy_pairs(struct uconfig_pair_s *pair)
+{
+	if (pair->next)
+		uconfig_destroy_pairs(pair->next);
+	free(pair->key);
+	free(pair->value);
+	free(pair);
+}
+
+void uconfig_destroy(struct uconfig_s *uconfig)
+{
+	uconfig_destroy_pairs(uconfig->head);
+}