How Do I Safely Copy a Go String to a C Char Pointer Using CGO?

Copying Go Strings to C Char Pointers Using CGO

When working with CGO in Go, a common requirement is to copy a Go string into a C char pointer. While it may seem straightforward to assign the Go string to the C pointer, the proper approach involves using the C.CString function.

Incorrect Copy Attempt

The code:

func copy_string(cstr *C.char) {

    str := "foo"
    C.GoString(cstr) = str

}

is incorrect because GoString is intended for converting C char pointers into Go strings, not vice versa.

Correct Copy Method

According to the CGO documentation, you should use C.CString to convert a Go string to a C string:

cstr = C.CString(str)

Memory Management

Note that C.CString allocates memory for the C string but does not release it. It is your responsibility to free this memory using a call to:

C.free(unsafe.Pointer(cstr))

when you are finished with the C string.

The above is the detailed content of How Do I Safely Copy a Go String to a C Char Pointer Using CGO?. For more information, please follow other related articles on the PHP Chinese website!