I'm trying to perform an XOR byte operation on every 3rd byte in an unsigned char array in my program. I'm having a type conversion error occur when I attempt to compile the program.
my declarations
unsigned char *s;
FILE *fp;
char ch;
int count = 0;
unsigned char *load = malloc(sizeof(char));
int i = 0;
s = "s";
and this is where the error is occurring...
for (i = 3; i < count;)
{
temp = (load[i-1] ^ s);
temp2 = (load[i] ^ s);
i = i + 3;
}
once I can get the XOR operation to work, I'll be setting load[i-1] = temp, right now I'm just trying to get the operation to compile and hopefully work.
Thanks in advance for any help / insight.
EDIT* Updated to give temp data type and show how unsigned char *load = malloc(sizeof(char)) is being used to take from data from a file.
char temp, temp2;
while ((ch = fgetc(fp)) != EOF)
{
load[i++] = ch;
}
and here is the error it is producing...
main.c:14:4: warning: assigning to 'unsigned char *' from 'char [2]' converts between pointers to integer types with different sign [-Wpointer-sign]
s = "s";
^ ~~~
main.c:86:21: error: invalid operands to binary expression ('int' and 'unsigned char *')
temp = (load[i-1] ^ s);
~~~~~~~~~ ^ ~
main.c:87:20: error: invalid operands to binary expression ('int' and 'unsigned char *')
temp2 = (load[i] ^ s);
You are allocating memory to hold only one unsigned char in
unsigned char *load = malloc(sizeof(char));
Then you are trying access the third character using load[i-1].
Update
The compiler error is very clear about the nature of the error
main.c:86:21: error: invalid operands to binary expression ('int' and 'unsigned char *')
temp = (load[i-1] ^ s);
Perhaps you meant to use:
temp = (load[i-1] ^ s[0]);
About the other compiler message, you can take care of that by initializing s when it is defined.
unsigned char *s = "S";
instead of assigning to it later.