# OSString A container for managing an array of characters. ``` class OSString; ``` ## Overview OSString is a container class for managing arrays of characters. *Encodings* OSString makes no provisions for different character encodings and assumes that a string is a nul-terminated sequence of single-byte characters. User-space code must either assume an encoding (typically ASCII or UTF-8) or determine it in some other way (such as an IORegistryEntry property). OSString is immutable. ## Topics ### Creating a String [`static OSStringPtr withString(const OSString *aString);`](/documentation/DriverKit/OSString/withString) Allocates an OSString object with a copy of an OString object. [`static OSStringPtr withCString(const char *cString);`](/documentation/DriverKit/OSString/withCString-4wsql) Allocates an OSString object with a copy of a c-string. [`static OSStringPtr withCString(const char *cString, size_t length);`](/documentation/DriverKit/OSString/withCString-721oh) Allocates an OSString object with a copy of a c-string, up to a given length. [`static OSStringPtr withCStringNoCopy(const char *cString);`](/documentation/DriverKit/OSString/withCStringNoCopy) Allocates an OSString object with a copy of a c-string. [`OSStringPtrOSStringCreate(const char *cstring, size_t length);`](/documentation/DriverKit/OSStringCreate) [`virtual void free();`](/documentation/DriverKit/OSString/free) ### Getting a C String [`const char * getCStringNoCopy() const;`](/documentation/DriverKit/OSString/getCStringNoCopy) Returns a pointer to the OSString object’s internal data buffer. [`const char *OSStringGetStringPtr(OSStringPtr obj);`](/documentation/DriverKit/OSStringGetStringPtr) [`typedef OSString * OSStringPtr;`](/documentation/DriverKit/OSStringPtr) ### Inspecting a String [`size_t getLength() const;`](/documentation/DriverKit/OSString/getLength) Returns length of string not including null terminator. [`size_t OSStringGetLength(OSStringPtr string);`](/documentation/DriverKit/OSStringGetLength) ### Comparing Strings [`bool isEqualTo(const OSData *aDataObject) const;`](/documentation/DriverKit/OSString/isEqualTo-1uq1f) Compares the string with an OSData. [`virtual bool isEqualTo(const OSMetaClassBase *anObject) const;`](/documentation/DriverKit/OSString/isEqualTo-712xj) Compares the string with an OSObject [`bool isEqualTo(const OSString *aString) const;`](/documentation/DriverKit/OSString/isEqualTo-5paj5) Compares the string with an OSString. [`bool isEqualTo(const char *cString) const;`](/documentation/DriverKit/OSString/isEqualTo-2rg80) Compares the string with a c-string. ## Relationships ### Inherits From [`OSContainer`](/documentation/DriverKit/OSContainer) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)