Initialize enum by string in c (keil v5)uvision

Question

I'm using these code to receive string from uart then matching them with this enum then putting them on switch-case.

char temp[3],rx_buf[100];
enum form {
GGA = 1,
GSA
};
enum form gnssform ;

sprintf(temp,"%c%c%c",rx_buf[3],rx_buf[4],rx_buf[5]);
gnssform=temp;

I can't understand that we can directly use something like EXAMPLE:

gnssform=GSA;

and there is no error ,but this:

gnssform=temp;

not compiling .and please tell me the possible way to do this???,because of this EXAMPLE I believe that it must be possible. the error is :

a value of type "char *" cannot be assigned to an entity of type "enum form"

please do not tell me to use if-else because I hate that.

Finally I used

if(rx_buf[3]=='G'&&rx_buf[4]=='G'&&rx_buf[5]=='A')gnssform=GGA; 
else if(rx_buf[3]=='G'&&rx_buf[4]=='S'&&rx_buf[5]=='A')gnssform=GSA;

Answer 1

GSA is a constant value of enum form.

temp is a char pointer to the three letters 'GSA'.

They are not the same thing, and you cannot directly assign them.