CHERI C/C++ Programming Guide

Printing capabilities with the printf(4) API family

When using the printf(3) family of APIs, the # qualifier to the p format string will cause additional architecture-specific information to be printed about a pointer. In CHERI C/C++, this prints out capability metadata as rendered using strfcap(3)'s %C format string. For example, the following code fragment:

int foo;
...
        printf("%%p:\t%p\n", &foo);
        printf("%%#p:\t%#p\n", &foo);

Will print out the following output in CheriBSD's CheriABI:

%p:	0x130b60
%#p:	0x130b60 [rwRW,0x130b60-0x130b64]