Shell: String to numeric conversion utils

Adds string to numeric conversion utility for shell.

Signed-off-by: Anders Storrø <anders.storro@nordicsemi.no>

include/shell/shell.h

@@ -12,6 +12,7 @@
 #include <shell/shell_history.h>
 #include <shell/shell_fprintf.h>
 #include <shell/shell_log_backend.h>
+#include <shell/shell_string_conv.h>
 #include <logging/log_instance.h>
 #include <logging/log.h>
 #include <sys/util.h>

include/shell/shell_string_conv.h

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2022 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef SHELL_STRING_CONV_H__
+#define SHELL_STRING_CONV_H__
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** @brief String to long conversion with error check.
+ *
+ * @warning On success the passed err reference will not be altered
+ * to avoid err check bloating. Passed err reference should be initialized
+ * to zero.
+ *
+ * @param str Input string.
+ * @param base Conversion base.
+ * @param err Error code pointer:
+ *         -EINVAL on invalid string input.
+ *         -ERANGE if numeric string input is to large to convert.
+ *         Unchanged on success.
+ *
+ * @return Converted long value.
+ */
+long shell_strtol(const char *str, int base, int *err);
+
+/** @brief String to unsigned long conversion with error check.
+ *
+ * @warning On success the passed err reference will not be altered
+ * to avoid err check bloating. Passed err reference should be initialized
+ * to zero.
+ *
+ * @param str Input string.
+ * @param base Conversion base.
+ * @param err Error code pointer:
+ *         Set to -EINVAL on invalid string input.
+ *         Set to -ERANGE if numeric string input is to large to convert.
+ *         Unchanged on success.
+ *
+ * @return Converted unsigned long value.
+ */
+unsigned long shell_strtoul(const char *str, int base, int *err);
+
+/** @brief String to boolean conversion with error check.
+ *
+ * @warning On success the passed err reference will not be altered
+ * to avoid err check bloating. Passed err reference should be initialized
+ * to zero.
+ *
+ * @param str Input string.
+ * @param base Conversion base.
+ * @param err Error code pointer:
+ *         Set to -EINVAL on invalid string input.
+ *         Set to -ERANGE if numeric string input is to large to convert.
+ *         Unchanged on success.
+ *
+ * @return Converted boolean value.
+ */
+bool shell_strtobool(const char *str, int base, int *err);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* SHELL_STRING_CONV_H__ */

subsys/shell/shell_utils.c

@@ -5,6 +5,7 @@
  */
 #include <ctype.h>
 #include <device.h>
+#include <stdlib.h>
 #include "shell_utils.h"
 #include "shell_wildcard.h"
 
@@ -471,3 +472,57 @@ const struct device *shell_device_lookup(size_t idx,
 
 	return NULL;
 }
+
+long shell_strtol(const char *str, int base, int *err)
+{
+	long val;
+	char *endptr = NULL;
+
+	errno = 0;
+	val = strtol(str, &endptr, base);
+	if (errno == ERANGE) {
+		*err = -ERANGE;
+		return 0;
+	} else if (errno || endptr == str || *endptr) {
+		*err = -EINVAL;
+		return 0;
+	}
+
+	return val;
+}
+
+unsigned long shell_strtoul(const char *str, int base, int *err)
+{
+	unsigned long val;
+	char *endptr = NULL;
+
+	if (*str == '-') {
+		*err = -EINVAL;
+		return 0;
+	}
+
+	errno = 0;
+	val = strtoul(str, &endptr, base);
+	if (errno == ERANGE) {
+		*err = -ERANGE;
+		return 0;
+	} else if (errno || endptr == str || *endptr) {
+		*err = -EINVAL;
+		return 0;
+	}
+
+	return val;
+}
+
+bool shell_strtobool(const char *str, int base, int *err)
+{
+	if (!strcmp(str, "on") || !strcmp(str, "enable") || !strcmp(str, "true")) {
+		return true;
+	}
+
+	if (!strcmp(str, "off") || !strcmp(str, "disable") || !strcmp(str, "false")) {
+		return false;
+	}
+
+	return shell_strtoul(str, base, err);
+}