feat(libx52io): Add _from_str and from_str_nocase APIs

This change add APIs to convert the string forms of the axis and button
names back to their corresponding enum identifiers. This is effectively
built such that a roundtrip of _to_str and _from_str will return the
same input. The _nocase variants handle case insensitive matching of the
names by folding of the ASCII alphabets A-Z and a-z only, so it doesn't
depend on localization.

libx52io/io_strings.c

@@ -8,6 +8,7 @@
 
 #include "config.h"
 #include <stdio.h>
+#include <string.h>
 #include "libx52io.h"
 #include "gettext.h"
 
@@ -16,6 +17,28 @@
  * on one to the enumeration definitions.
  */
 
+/* Locale-independent: only ASCII A–Z fold with a–z; digits and underscore unchanged */
+static int x52io_ascii_strcasecmp(const char *a, const char *b)
+{
+    for (;;) {
+        unsigned char ca = (unsigned char)*a++;
+        unsigned char cb = (unsigned char)*b++;
+
+        if (ca >= 'A' && ca <= 'Z') {
+            ca = (unsigned char)(ca - 'A' + 'a');
+        }
+        if (cb >= 'A' && cb <= 'Z') {
+            cb = (unsigned char)(cb - 'A' + 'a');
+        }
+        if (ca != cb) {
+            return (int)ca - (int)cb;
+        }
+        if (ca == '\0') {
+            return 0;
+        }
+    }
+}
+
 /* String mapping for axis */
 static const char * _x52io_axis_str[LIBX52IO_AXIS_MAX] = {
     [LIBX52IO_AXIS_X] = "ABS_X",
@@ -92,6 +115,78 @@ const char * libx52io_button_to_str(libx52io_button button)
     return NULL;
 }
 
+int libx52io_axis_from_str(const char *str, libx52io_axis *axis)
+{
+    libx52io_axis i;
+
+    if (!str || !axis) {
+        return LIBX52IO_ERROR_INVALID;
+    }
+
+    for (i = LIBX52IO_AXIS_X; i < LIBX52IO_AXIS_MAX; i++) {
+        if (strcmp(str, _x52io_axis_str[i]) == 0) {
+            *axis = i;
+            return LIBX52IO_SUCCESS;
+        }
+    }
+
+    return LIBX52IO_ERROR_INVALID;
+}
+
+int libx52io_button_from_str(const char *str, libx52io_button *button)
+{
+    libx52io_button b;
+
+    if (!str || !button) {
+        return LIBX52IO_ERROR_INVALID;
+    }
+
+    for (b = LIBX52IO_BTN_TRIGGER; b < LIBX52IO_BUTTON_MAX; b++) {
+        if (strcmp(str, _x52io_button_str[b]) == 0) {
+            *button = b;
+            return LIBX52IO_SUCCESS;
+        }
+    }
+
+    return LIBX52IO_ERROR_INVALID;
+}
+
+int libx52io_axis_from_str_nocase(const char *str, libx52io_axis *axis)
+{
+    libx52io_axis i;
+
+    if (!str || !axis) {
+        return LIBX52IO_ERROR_INVALID;
+    }
+
+    for (i = LIBX52IO_AXIS_X; i < LIBX52IO_AXIS_MAX; i++) {
+        if (x52io_ascii_strcasecmp(str, _x52io_axis_str[i]) == 0) {
+            *axis = i;
+            return LIBX52IO_SUCCESS;
+        }
+    }
+
+    return LIBX52IO_ERROR_INVALID;
+}
+
+int libx52io_button_from_str_nocase(const char *str, libx52io_button *button)
+{
+    libx52io_button b;
+
+    if (!str || !button) {
+        return LIBX52IO_ERROR_INVALID;
+    }
+
+    for (b = LIBX52IO_BTN_TRIGGER; b < LIBX52IO_BUTTON_MAX; b++) {
+        if (x52io_ascii_strcasecmp(str, _x52io_button_str[b]) == 0) {
+            *button = b;
+            return LIBX52IO_SUCCESS;
+        }
+    }
+
+    return LIBX52IO_ERROR_INVALID;
+}
+
 /* Error buffer used for building custom error strings */
 static char error_buffer[256];
 

libx52io/libx52io.h

@@ -434,6 +434,62 @@ LIBX52IO_API const char *libx52io_axis_to_str(libx52io_axis axis);
  */
 LIBX52IO_API const char *libx52io_button_to_str(libx52io_button button);
 
+/**
+ * @brief Parse the string representation of an axis.
+ *
+ * Accepts tokens as returned by \ref libx52io_axis_to_str (e.g. \c ABS_X).
+ *
+ * @param[in]   str     NUL-terminated axis name
+ * @param[out]  axis    Receives the axis ID on success
+ *
+ * @returns \ref LIBX52IO_SUCCESS if \a str was recognized,
+ *   \ref LIBX52IO_ERROR_INVALID if \a str or \a axis is NULL or \a str is unknown.
+ */
+LIBX52IO_API int libx52io_axis_from_str(const char *str, libx52io_axis *axis);
+
+/**
+ * @brief Parse the string representation of a button.
+ *
+ * Accepts tokens as returned by \ref libx52io_button_to_str (e.g. \c BTN_FIRE).
+ *
+ * @param[in]   str     NUL-terminated button name
+ * @param[out]  button  Receives the button ID on success
+ *
+ * @returns \ref LIBX52IO_SUCCESS if \a str was recognized,
+ *   \ref LIBX52IO_ERROR_INVALID if \a str or \a button is NULL or \a str is unknown.
+ */
+LIBX52IO_API int libx52io_button_from_str(const char *str, libx52io_button *button);
+
+/**
+ * @brief Parse an axis name with ASCII case-insensitive matching.
+ *
+ * Like \ref libx52io_axis_from_str, but treats ASCII letters \c A– \c Z the same
+ * as \c a– \c z. Digits, underscore, and NUL must match exactly. Matching is
+ * not locale-dependent.
+ *
+ * @param[in]   str     NUL-terminated axis name
+ * @param[out]  axis    Receives the axis ID on success
+ *
+ * @returns \ref LIBX52IO_SUCCESS if \a str was recognized,
+ *   \ref LIBX52IO_ERROR_INVALID if \a str or \a axis is NULL or \a str is unknown.
+ */
+LIBX52IO_API int libx52io_axis_from_str_nocase(const char *str, libx52io_axis *axis);
+
+/**
+ * @brief Parse a button name with ASCII case-insensitive matching.
+ *
+ * Like \ref libx52io_button_from_str, but treats ASCII letters \c A– \c Z the same
+ * as \c a– \c z. Digits, underscore, and NUL must match exactly. Matching is
+ * not locale-dependent.
+ *
+ * @param[in]   str     NUL-terminated button name
+ * @param[out]  button  Receives the button ID on success
+ *
+ * @returns \ref LIBX52IO_SUCCESS if \a str was recognized,
+ *   \ref LIBX52IO_ERROR_INVALID if \a str or \a button is NULL or \a str is unknown.
+ */
+LIBX52IO_API int libx52io_button_from_str_nocase(const char *str, libx52io_button *button);
+
 /**
  * @brief Get the vendor ID of the connected X52 device.
  *

libx52io/meson.build

@@ -1,4 +1,4 @@
-libx52io_version = '1.0.0'
+libx52io_version = '1.1.0'
 
 libx52io_files = files(
   'io_core.c',
@@ -37,4 +37,11 @@ test_parser = executable('test-parser', 'test_parser.c', libx52io_files,
 )
 test('test-parser', test_parser, protocol: 'tap')
 
+test_io_strings = executable('test-io-strings', 'test_io_strings.c', libx52io_files,
+  build_by_default: false,
+  dependencies: [dep_cmocka, dep_hidapi, dep_intl],
+  include_directories: [includes],
+)
+test('test-io-strings', test_io_strings, protocol: 'tap')
+
 

libx52io/test_io_strings.c

@@ -0,0 +1,191 @@
+/*
+ * Saitek X52 IO driver - io string parse tests
+ *
+ * Copyright (C) 2012-2020 Nirenjan Krishnan (nirenjan@nirenjan.org)
+ *
+ * SPDX-License-Identifier: GPL-2.0-only WITH Classpath-exception-2.0
+ */
+
+#include <stdarg.h>
+#include <stddef.h>
+#include <setjmp.h>
+#include <cmocka.h>
+
+#include "libx52io.h"
+
+static void lower_ascii_only(char *dst, const char *src)
+{
+    for (; *src; src++, dst++) {
+        unsigned char c = (unsigned char)*src;
+
+        if (c >= 'A' && c <= 'Z') {
+            c = (unsigned char)(c - 'A' + 'a');
+        }
+        *dst = (char)c;
+    }
+    *dst = '\0';
+}
+
+static void test_axis_round_trip(void **state)
+{
+    libx52io_axis a;
+    libx52io_axis out;
+
+    (void)state;
+
+    for (a = LIBX52IO_AXIS_X; a < LIBX52IO_AXIS_MAX; a++) {
+        const char *s = libx52io_axis_to_str(a);
+
+        assert_non_null(s);
+        assert_int_equal(LIBX52IO_SUCCESS, libx52io_axis_from_str(s, &out));
+        assert_int_equal(a, out);
+        assert_ptr_equal(s, libx52io_axis_to_str(out));
+    }
+}
+
+static void test_button_round_trip(void **state)
+{
+    libx52io_button b;
+    libx52io_button out;
+
+    (void)state;
+
+    for (b = LIBX52IO_BTN_TRIGGER; b < LIBX52IO_BUTTON_MAX; b++) {
+        const char *s = libx52io_button_to_str(b);
+
+        assert_non_null(s);
+        assert_int_equal(LIBX52IO_SUCCESS, libx52io_button_from_str(s, &out));
+        assert_int_equal(b, out);
+        assert_ptr_equal(s, libx52io_button_to_str(out));
+    }
+}
+
+static void test_axis_from_str_invalid(void **state)
+{
+    libx52io_axis out;
+
+    (void)state;
+
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str("", &out));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str("ABS_", &out));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str("ABS_XX", &out));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str("abs_x", &out));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str("BTN_FIRE", &out));
+}
+
+static void test_button_from_str_invalid(void **state)
+{
+    libx52io_button out;
+
+    (void)state;
+
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_button_from_str("", &out));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_button_from_str("BTN_", &out));
+    assert_int_equal(LIBX52IO_ERROR_INVALID,
+        libx52io_button_from_str("BTN_FIRE_EXTRA", &out));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_button_from_str("btn_fire", &out));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_button_from_str("ABS_X", &out));
+}
+
+static void test_from_str_null_args(void **state)
+{
+    libx52io_axis ax;
+    libx52io_button btn;
+
+    (void)state;
+
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str(NULL, &ax));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str("ABS_X", NULL));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_button_from_str(NULL, &btn));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_button_from_str("BTN_A", NULL));
+}
+
+static void test_axis_from_str_nocase(void **state)
+{
+    libx52io_axis a;
+    libx52io_axis out;
+    char buf[64];
+
+    (void)state;
+
+    for (a = LIBX52IO_AXIS_X; a < LIBX52IO_AXIS_MAX; a++) {
+        const char *s = libx52io_axis_to_str(a);
+
+        assert_non_null(s);
+        lower_ascii_only(buf, s);
+        assert_int_equal(LIBX52IO_SUCCESS, libx52io_axis_from_str_nocase(buf, &out));
+        assert_int_equal(a, out);
+    }
+
+    assert_int_equal(LIBX52IO_SUCCESS,
+        libx52io_axis_from_str_nocase("aBs_hAtX", &out));
+    assert_int_equal(LIBX52IO_AXIS_HATX, out);
+}
+
+static void test_button_from_str_nocase(void **state)
+{
+    libx52io_button b;
+    libx52io_button out;
+    char buf[64];
+
+    (void)state;
+
+    for (b = LIBX52IO_BTN_TRIGGER; b < LIBX52IO_BUTTON_MAX; b++) {
+        const char *s = libx52io_button_to_str(b);
+
+        assert_non_null(s);
+        lower_ascii_only(buf, s);
+        assert_int_equal(LIBX52IO_SUCCESS, libx52io_button_from_str_nocase(buf, &out));
+        assert_int_equal(b, out);
+    }
+
+    assert_int_equal(LIBX52IO_SUCCESS,
+        libx52io_button_from_str_nocase("BtN_t1_dN", &out));
+    assert_int_equal(LIBX52IO_BTN_T1_DN, out);
+}
+
+static void test_from_str_nocase_invalid(void **state)
+{
+    libx52io_axis ax;
+    libx52io_button btn;
+
+    (void)state;
+
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str_nocase("", &ax));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str_nocase("abs_xx", &ax));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_button_from_str_nocase("", &btn));
+    assert_int_equal(LIBX52IO_ERROR_INVALID,
+        libx52io_button_from_str_nocase("btn_fire_extra", &btn));
+}
+
+static void test_from_str_nocase_null_args(void **state)
+{
+    libx52io_axis ax;
+    libx52io_button btn;
+
+    (void)state;
+
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str_nocase(NULL, &ax));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_axis_from_str_nocase("abs_x", NULL));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_button_from_str_nocase(NULL, &btn));
+    assert_int_equal(LIBX52IO_ERROR_INVALID, libx52io_button_from_str_nocase("btn_a", NULL));
+}
+
+int main(void)
+{
+    const struct CMUnitTest tests[] = {
+        cmocka_unit_test(test_axis_round_trip),
+        cmocka_unit_test(test_button_round_trip),
+        cmocka_unit_test(test_axis_from_str_invalid),
+        cmocka_unit_test(test_button_from_str_invalid),
+        cmocka_unit_test(test_from_str_null_args),
+        cmocka_unit_test(test_axis_from_str_nocase),
+        cmocka_unit_test(test_button_from_str_nocase),
+        cmocka_unit_test(test_from_str_nocase_invalid),
+        cmocka_unit_test(test_from_str_nocase_null_args),
+    };
+
+    cmocka_set_message_output(CM_OUTPUT_TAP);
+    cmocka_run_group_tests(tests, NULL, NULL);
+    return 0;
+}

po/libx52.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: libx52 0.3.3\n"
 "Report-Msgid-Bugs-To: https://github.com/nirenjan/libx52/issues\n"
-"POT-Creation-Date: 2026-04-02 23:18-0700\n"
+"POT-Creation-Date: 2026-04-02 23:32-0700\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -17,11 +17,11 @@ msgstr ""
 "Content-Type: text/plain; charset=CHARSET\n"
 "Content-Transfer-Encoding: 8bit\n"
 
-#: libx52/x52_strerror.c:23 libx52io/io_strings.c:101 vkm/vkm_common.c:25
+#: libx52/x52_strerror.c:23 libx52io/io_strings.c:196 vkm/vkm_common.c:25
 msgid "Success"
 msgstr ""
 
-#: libx52/x52_strerror.c:24 libx52io/io_strings.c:102
+#: libx52/x52_strerror.c:24 libx52io/io_strings.c:197
 msgid "Initialization failure"
 msgstr ""
 
@@ -85,7 +85,7 @@ msgstr ""
 msgid "System call interrupted"
 msgstr ""
 
-#: libx52/x52_strerror.c:66 libx52io/io_strings.c:125 vkm/vkm_common.c:52
+#: libx52/x52_strerror.c:66 libx52io/io_strings.c:220 vkm/vkm_common.c:52
 #, c-format
 msgid "Unknown error %d"
 msgstr ""
@@ -213,23 +213,23 @@ msgstr ""
 msgid "Unknown LED ID %d"
 msgstr ""
 
-#: libx52io/io_strings.c:103
+#: libx52io/io_strings.c:198
 msgid "No device"
 msgstr ""
 
-#: libx52io/io_strings.c:104
+#: libx52io/io_strings.c:199
 msgid "Invalid arguments"
 msgstr ""
 
-#: libx52io/io_strings.c:105
+#: libx52io/io_strings.c:200
 msgid "Connection failure"
 msgstr ""
 
-#: libx52io/io_strings.c:106
+#: libx52io/io_strings.c:201
 msgid "I/O error"
 msgstr ""
 
-#: libx52io/io_strings.c:107
+#: libx52io/io_strings.c:202
 msgid "Read timeout"
 msgstr ""
 

po/xx_PL.po

@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: libx52 0.2.3\n"
 "Report-Msgid-Bugs-To: https://github.com/nirenjan/libx52/issues\n"
-"POT-Creation-Date: 2026-04-02 23:18-0700\n"
+"POT-Creation-Date: 2026-04-02 23:32-0700\n"
 "PO-Revision-Date: 2026-04-01 20:50-0700\n"
 "Last-Translator: Nirenjan Krishnan <nirenjan@gmail.com>\n"
 "Language-Team: Dummy Language for testing i18n\n"
@@ -17,11 +17,11 @@ msgstr ""
 "Content-Transfer-Encoding: 8bit\n"
 "X-Generator: Poedit 3.4.2\n"
 
-#: libx52/x52_strerror.c:23 libx52io/io_strings.c:101 vkm/vkm_common.c:25
+#: libx52/x52_strerror.c:23 libx52io/io_strings.c:196 vkm/vkm_common.c:25
 msgid "Success"
 msgstr "Uccesssay"
 
-#: libx52/x52_strerror.c:24 libx52io/io_strings.c:102
+#: libx52/x52_strerror.c:24 libx52io/io_strings.c:197
 msgid "Initialization failure"
 msgstr "Initializationay ailurefay"
 
@@ -85,7 +85,7 @@ msgstr "Ipepay erroray"
 msgid "System call interrupted"
 msgstr "Ystemsay allcay interrupteday"
 
-#: libx52/x52_strerror.c:66 libx52io/io_strings.c:125 vkm/vkm_common.c:52
+#: libx52/x52_strerror.c:66 libx52io/io_strings.c:220 vkm/vkm_common.c:52
 #, c-format
 msgid "Unknown error %d"
 msgstr "Unknownay erroray %d"
@@ -213,23 +213,23 @@ msgstr "Ottlethray"
 msgid "Unknown LED ID %d"
 msgstr "Unknownay EDLay IDay %d"
 
-#: libx52io/io_strings.c:103
+#: libx52io/io_strings.c:198
 msgid "No device"
 msgstr "Onay eviceday"
 
-#: libx52io/io_strings.c:104
+#: libx52io/io_strings.c:199
 msgid "Invalid arguments"
 msgstr "Invaliday argumentsay"
 
-#: libx52io/io_strings.c:105
+#: libx52io/io_strings.c:200
 msgid "Connection failure"
 msgstr "Onnectioncay ailurefay"
 
-#: libx52io/io_strings.c:106
+#: libx52io/io_strings.c:201
 msgid "I/O error"
 msgstr "I/O erroray"
 
-#: libx52io/io_strings.c:107
+#: libx52io/io_strings.c:202
 msgid "Read timeout"
 msgstr "Eadray imeouttay"