Igor’s Tip of the Week #179: Bitmask enums

We’ve covered simple enums previously, but there is a different kind of enums that you may sometimes encounter or need to create manually. They are used to represent various bits (or flags) which may be set in an integer value. For example, the file mode on Unix filesystems contains Access Permission bits (you can see them in the output of ls as string like -rwxr-xr-x), and each bit has a corresponding constant:

#define S_IRWXU 00700
#define S_IRUSR …

access bits file integer kind malware analysis may mode permission simple unix value week