1 files changed, 93 insertions, 0 deletions
diff --git a/src/sort.c b/src/sort.c
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+/*
+ * libiio - Library for interfacing industrial I/O (IIO) devices
+ *
+ * Copyright (C) 2018 Analog Devices, Inc.
+ * Author: Robin Getz <robin.getz@analog.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * */
+
+#include "iio-private.h"
+#include <string.h>
+
+/* These are a few functions to do sorting via qsort for various
+ * iio structures. For more info, see the qsort(3) man page.
+ *
+ * The qsort comparison function must return an integer less than, equal to,
+ * or greater than zero if the first argument is considered to be
+ * respectively less than, equal to, or greater than the second. If two
+ * members compare as equal, their order in the sort order is undefined.
+ *
+ * If the structures are updated, the compare functions may
+ * need to be updated.
+ *
+ * The actual arguments to these function are "pointers to
+ * pointers to char", but strcmp(3) arguments are "pointers
+ * to char", hence the cast plus dereference
+ */
+
+int iio_channel_compare(const void *p1, const void *p2)
+{
+	const struct iio_channel *tmp1 = *(struct iio_channel **)p1;
+	const struct iio_channel *tmp2 = *(struct iio_channel **)p2;
+
+	/* make sure buffer enabled channels are first */
+	if (iio_channel_is_scan_element(tmp1) && !iio_channel_is_scan_element(tmp2))
+		return -1;
+	if (!iio_channel_is_scan_element(tmp1) && iio_channel_is_scan_element(tmp2))
+		return 1;
+	/* and sort them by index */
+	if (iio_channel_is_scan_element(tmp1) && iio_channel_is_scan_element(tmp2)){
+		if (iio_channel_get_index(tmp1) > iio_channel_get_index(tmp2))
+			return 1;
+		return -1;
+	}
+	/* otherwise, if the ID is the same, input channels first */
+	if (strcmp(tmp1->id, tmp2->id) == 0)
+		return !iio_channel_is_output(tmp1);
+
+	/* finally by ID */
+	return strcmp(tmp1->id, tmp2->id);
+}
+
+int iio_channel_attr_compare(const void *p1, const void *p2)
+{
+	const struct iio_channel_attr *tmp1 = (struct iio_channel_attr *)p1;
+	const struct iio_channel_attr *tmp2 = (struct iio_channel_attr *)p2;
+	/* qsort channel attributes by name */
+	return strcmp(tmp1->name, tmp2->name);
+}
+
+int iio_device_compare(const void *p1, const void *p2)
+{
+	const struct iio_device *tmp1 = *(struct iio_device **)p1;
+	const struct iio_device *tmp2 = *(struct iio_device **)p2;
+	/* qsort devices by ID */
+	return strcmp(tmp1->id, tmp2->id);
+}
+
+int iio_device_attr_compare(const void *p1, const void *p2)
+{
+	const char *tmp1 = *(const char **)p1;
+	const char *tmp2 = *(const char **)p2;
+	/* qsort device attributes by name */
+	return strcmp(tmp1, tmp2);
+}
+
+int iio_buffer_attr_compare(const void *p1, const void *p2)
+{
+	const char *tmp1 = *(const char **)p1;
+	const char *tmp2 = *(const char **)p2;
+	/* qsort buffer attributes by name */
+	return strcmp(tmp1, tmp2);
+}
+