Add initial version of i3-input, an interactive tool for sending IPC commands

i3-input/ucs2_to_utf8.c

@@ -0,0 +1,55 @@
+/*
+ * vim:ts=8:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ *
+ * © 2009 Michael Stapelberg and contributors
+ *
+ * See file LICENSE for license information.
+ *
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <err.h>
+#include <iconv.h>
+
+static iconv_t conversion_descriptor = 0;
+
+/*
+ * Returns the input string, but converted from UCS-2 to UTF-8. Memory will be
+ * allocated, thus the caller has to free the output.
+ *
+ */
+char *convert_ucs_to_utf8(char *input) {
+	size_t input_size = 2;
+	/* UTF-8 may consume up to 4 byte */
+	int buffer_size = 8;
+
+	char *buffer = calloc(buffer_size, 1);
+        if (buffer == NULL)
+                err(EXIT_FAILURE, "malloc() failed\n");
+	size_t output_size = buffer_size;
+	/* We need to use an additional pointer, because iconv() modifies it */
+	char *output = buffer;
+
+	/* We convert the input into UCS-2 big endian */
+        if (conversion_descriptor == 0) {
+                conversion_descriptor = iconv_open("UTF-8", "UCS-2BE");
+                if (conversion_descriptor == 0) {
+                        fprintf(stderr, "error opening the conversion context\n");
+                        exit(1);
+                }
+        }
+
+	/* Get the conversion descriptor back to original state */
+	iconv(conversion_descriptor, NULL, NULL, NULL, NULL);
+
+	/* Convert our text */
+	int rc = iconv(conversion_descriptor, (void*)&input, &input_size, &output, &output_size);
+        if (rc == (size_t)-1) {
+                perror("Converting to UCS-2 failed");
+                return NULL;
+	}
+
+	return buffer;
+}