code import

.gitignore

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+*.obj
+*.so
+*.out
+*.a
+CMakeLists.txt
+cmake-build-*/

Makefile

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+a.out: test.c nini.c
+	cc -Og test.c nini.c
+
+run: a.out
+	./a.out

README.md

@@ -1,2 +1,36 @@
-# nini
-Nano INI parser
+# NINI
+
+This parser aims to be the smallest possible while supporting a sufficient subset of the INI format.
+The parser is meant for use in embedded applications.
+
+When compiled for a bare metal Cortex-M0, **the whole parser fits in 336 bytes** of Flash and 30 (+buffers) bytes of RAM.
+
+## Features
+
+- Basic INI format support
+- Accepts both Unix and DOS newlines
+- Minimal memory footprint
+- The input file can be loaded in multiple pieces of any size.
+- Buffer sizes (section, key, value) can be configured in the header file.
+- Custom data `void *` for maintaining user context, passed to the callback
+
+## Sypported syntax
+
+Any whitespace, except inside a value, is discarded.
+
+- **Sections** - `[section.name]`
+- **Key-value pairs** - `key.foo-bar_baz123 = value lorem ipsum 123`
+  - Value can contain whitespace, leading and trailing whitespace is removed.
+  - Ends with either `\r` or `\n`
+- **Comment** `# comment ...`
+  - Ends with either `\r` or `\n`
+
+## Limitations
+
+- Not re-entrant, uses a static state variable
+- No checks for invalid syntax
+- Whitespace inside keys and section names is removed
+- Quoted strings and escape sequences are not supported, will be collected as plain text
+- Value can't be followed by an inline comment
+
+See the file `test.c` for an example of the most basic usage; see the header file for more details on the API.

nini.c

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+///
+/// nini - Nano INI parser
+/// 
+/// Written by MightyPork, 2018
+/// MIT license
+/// 
+
+
+#include "nini.h"
+
+enum nini_state {
+    NINI_IDLE,
+    NINI_SECTION,
+    NINI_KEY,
+    NINI_VALUE,
+    NINI_COMMENT,
+};
+
+static struct {
+    uint8_t section_i;
+    char section[INI_KEY_MAX];
+
+    uint8_t key_i;
+    char key[INI_KEY_MAX];
+
+    uint8_t value_i;
+    char value[INI_VALUE_MAX];
+    bool val_last_space;
+
+    IniParserCallback cb;
+    void *userdata;
+    enum nini_state state;
+} nini;
+
+void ini_parse_begin(IniParserCallback callback, void *userData)
+{
+    ini_parse_reset();
+    nini.cb = callback;
+    nini.userdata = userData;
+}
+
+void ini_parse(const char *data, size_t len)
+{
+    for (; len > 0; len--) {
+        char c = *data++;
+        if (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
+            if (nini.state != NINI_VALUE && nini.state != NINI_COMMENT)
+                continue;
+        }
+
+        switch (nini.state) {
+            case NINI_IDLE:
+                if (c == '[') {
+                    nini.state = NINI_SECTION;
+                    nini.section_i = 0;
+                }
+                else if (c == '#') {
+                    nini.state = NINI_COMMENT;
+                }
+                else {
+                    nini.state = NINI_KEY;
+                    nini.key_i = 0;
+                    nini.value_i = 0;
+                    nini.val_last_space = false;
+                    nini.key[nini.key_i++] = c;
+                }
+                break;
+
+            case NINI_COMMENT:
+                if (c == '\n' || c == '\r') {
+                    nini.state = NINI_IDLE;
+                }
+                break;
+
+            case NINI_SECTION:
+                if (c == ']') {
+                    nini.section[nini.section_i] = 0;
+                    nini.state = NINI_COMMENT; // discard to EOL
+                    break;
+                }
+                else if (nini.section_i < INI_KEY_MAX - 1) {
+                    nini.section[nini.section_i++] = c;
+                }
+                break;
+
+            case NINI_KEY:
+                if (c == '=') {
+                    nini.key[nini.key_i] = 0;
+                    nini.state = NINI_VALUE;
+                }
+                else if (nini.key_i < INI_KEY_MAX - 1) {
+                    nini.key[nini.key_i++] = c;
+                }
+                break;
+
+            case NINI_VALUE:
+                switch (c) {
+                    case ' ':
+                    case '\t':
+                        if (nini.value_i) nini.val_last_space = true;
+                        break;
+                    case '\r':
+                    case '\n':
+                        nini.value[nini.value_i] = 0;
+                        nini.state = NINI_IDLE;
+                        nini.cb(nini.section, nini.key, nini.value, nini.userdata);
+                        break;
+                    default:
+                        if (nini.val_last_space && nini.value_i < INI_VALUE_MAX - 1) {
+                            nini.value[nini.value_i++] = ' ';
+                        }
+
+                        if (nini.value_i < INI_VALUE_MAX - 1) {
+                            nini.value[nini.value_i++] = c;
+                        }
+                        nini.val_last_space = false;
+                }
+        }
+    }
+}
+
+void *ini_parse_end(void)
+{
+    if (nini.state == NINI_VALUE) {
+        nini.value[nini.value_i] = 0;
+        nini.state = NINI_IDLE;
+        nini.cb(nini.section, nini.key, nini.value, nini.userdata);
+    }
+
+    return nini.userdata;
+}
+
+void ini_parse_file(const char *text, size_t len, IniParserCallback callback, void *userData)
+{
+    ini_parse_begin(callback, userData);
+    ini_parse(text, len);
+    ini_parse_end();
+}
+
+void ini_parse_reset(void)
+{
+    nini.state = NINI_IDLE;
+}

nini.h

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+///
+/// nini - Nano INI parser
+/// 
+/// Written by MightyPork, 2018
+/// MIT license
+/// 
+
+#ifndef INIPARSE_H
+#define INIPARSE_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+// buffer sizes
+#define INI_KEY_MAX 20
+#define INI_VALUE_MAX 30
+
+/**
+ * INI parser callback, called for each found key-value pair.
+ *
+ * @param section - current section, empty string for global keys
+ * @param key - found key (trimmed of whitespace)
+ * @param value - value, trimmed of quotes or whitespace
+ * @param userData - opaque user data pointer, general purpose
+ */
+typedef void (*IniParserCallback)(const char *section, const char *key, const char *value, void *userData);
+
+/**
+ * Begin parsing a stream
+ *
+ * @param callback - key callback to assign
+ * @param userData - optional user data that will be passed to the callback
+ */
+void ini_parse_begin(IniParserCallback callback, void *userData);
+
+/**
+ * End parse stream.
+ * Flushes what remains in the buffer and removes callback.
+ *
+ * @returns userData or NULL if none
+ */
+void* ini_parse_end(void);
+
+/**
+ * Parse a string (needn't be complete line or file)
+ *
+ * @param data - string to parse
+ * @param len - string length (0 = use strlen)
+ */
+void ini_parse(const char *data, size_t len);
+
+/**
+ * Parse a complete file loaded to string
+ *
+ * @param text - entire file as string
+ * @param len - file length (0 = use strlen)
+ * @param callback - key callback
+ * @param userData - optional user data for key callback
+ */
+void ini_parse_file(const char *text, size_t len, IniParserCallback callback, void *userData);
+
+/**
+ * Explicitly reset the parser
+ */
+void ini_parse_reset(void);
+
+#endif // INIPARSE_H

test.c

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+#include "nini.h"
+#include <string.h>
+
+const char *testfile = 
+"# Comment  ...........\n"
+"rootkey = Value\r\n"
+"\r\n"
+" [ Section@name!@+12346   ]\r\n"
+"sec.key-a_b-1 = 444\r\n"
+"sec.key2 = Test 123456 with spaces\r\n"
+    "[ this is a section with spaces nthat will be removed ]\n"
+"this_one_has_no_eol = 123456";
+
+
+void test_cb(const char *section, const char *key, const char *value, void *userData)
+{
+    printf("[%s] >%s< = >%s<\r\n", section, key, value);
+}
+
+int main (void) {
+    ini_parse_file(testfile, strlen(testfile), test_cb, NULL);
+}