1 files changed, 136 insertions, 0 deletions
diff --git a/include/parcini.h b/include/parcini.h
new file mode 100644
index 0000000..3bcaf59
--- /dev/null
+++ b/include/parcini.h
@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2021 Yaroslav de la Peña Smirnov
+ *
+ * Released under the GNU Lesser General Public License, version 2.1 only.
+ * For more information see `LICENSE' or visit
+ * https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
+ */
+#ifndef PARCINI_H
+#define PARCINI_H
+#include <stdio.h>
+#include <stdbool.h>
+#include <sys/types.h>
+
+/* You can choose to use a different character for comments (e.g. ';') at
+ * compile time */
+#ifndef PARCINI_COMMENT_CHAR
+#define PARCINI_COMMENT_CHAR '#'
+#endif
+
+/*
+ * An opaque structure that represents an instance of a "parcini" ini parser,
+ * used to parse a stream.
+ */
+typedef struct parcini parcini_t;
+
+/*
+ * All possible values to be returned by parcini_parse_next_line.
+ */
+enum parcini_result {
+	/* A line with only whitespace and/or a comment */
+	PARCINI_EMPTY_LINE,
+	/* There are no more lines to parse */
+	PARCINI_EOF,
+	/* A section. parcini_line.key shall be NULL and parcini_line.value.type
+	 * shalle be PARCINI_VALUE_NONE */
+	PARCINI_SECTION,
+	/* Key/value. parcini_line.key contains the name of the key, and
+	 * parcini_line.value contains the type and actual value. */
+	PARCINI_KEYVALUE,
+	/* A call to malloc/realloc failed. errno might be set */
+	PARCINI_MEMORY_ERROR,
+	/* An error other than EOF occured when attempting to read the stream. errno
+	 * might be set */
+	PARCINI_STREAM_ERROR,
+	/* What seemed to start as a key is incorrectly formated, and thus couldn't
+	 * be parsed correctly. */
+	PARCINI_KEY_PARSE_ERROR,
+	/* Where a value should have followed a key, there is none, or it is
+	 * incorrectly formated, and thus couldn't be parsed correctly. */
+	PARCINI_VALUE_PARSE_ERROR,
+	/* The value is an integer number that couldn't be parsed correctly due to
+	 * it being out of the range of a long int */
+	PARCINI_VALUE_RANGE_ERROR,
+	/* What seemed to be a line containing a section name, wasn't formatted
+	 * correctly and thus couldn't be parsed. */
+	PARCINI_SECTION_PARSE_ERROR,
+};
+
+enum parcini_value_type {
+	/* There is no value */
+	PARCINI_VALUE_NONE,
+	/* The value is long int */
+	PARCINI_VALUE_INTEGER,
+	/* The value is bool */
+	PARCINI_VALUE_BOOLEAN,
+	/* The value is pointer to char */
+	PARCINI_VALUE_STRING,
+};
+
+/*
+ * A tagged union-like structure representing a parsed value. Accessing a .value
+ * member for which the type is not set is undefined behaviour (beware of the
+ * char *, it could segfault your program).
+ */
+struct parcini_value {
+	enum parcini_value_type type;
+	union {
+		long int integer;
+		bool boolean;
+		char *string;
+	} value;
+};
+
+/*
+ * This structure should be passed as a pointer to parcini_parse_next_line so
+ * that it is filled with the parsed information. The pointers here MUST NOT be
+ * manually freed. See function parcini_parse_next_line for more details.
+ */
+struct parcini_line {
+	size_t lineno;
+	char *section;
+	char *key;
+	struct parcini_value value;
+};
+
+/*
+ * Parse the next line in the stream returning the kind of result/error of
+ * parsing and filling the parcini_line structure with the information that was
+ * extracted from the line, as well as the current section (including after
+ * parsing a key/value line) and line number.
+ * 
+ * If you need the information returned to last after the next call to this
+ * function, or after the destruction of the parcini_t parser instance, then you
+ * should copy it to a different variable/pointer before parsing the next
+ * line/freeing your parser instance. This data also MUST NOT be manually freed
+ * by the caller.
+ */
+enum parcini_result parcini_parse_next_line(parcini_t *, struct parcini_line *);
+
+/*
+ * Main function through which you initialize a parcini_t parser object, before
+ * you can parse the stream line by line.
+ */
+parcini_t *parcini_init(FILE *stream);
+
+/*
+ * Helper function to open a file and then initialize a parcini_t object with
+ * said as the source stream.
+ */
+parcini_t *parcini_from_file(const char *fpath);
+
+/*
+ * Helper function to initialize a parcini_t object with said string of said
+ * size open as a stream.
+ */
+parcini_t *parcini_from_string(const char *, const size_t);
+
+/*
+ * Free all memory related to the parcini_t instance. IMPORTANT: this will also
+ * close the stream passed to parcini_init, so if you manually opened a file and
+ * then passed it to parcini_init, it WILL NOT be valid after a call to
+ * parcini_destroy.
+ */
+void parcini_destroy(parcini_t *);
+
+#endif