The following is the field definition from Linux man proc(5).
SigPnd, ShdPnd: Number of signals pending for thread and for process as a whole (see pthreads(7) and signal(7)).
SigBlk, SigIgn, SigCgt: Masks indicating signals being blocked, ignored, and caught (see signal(7)).
But what they look like and how to interpret? Here is an output example:
SigPnd: 0000000000000000 ShdPnd: 0000000000000000 SigBlk: fffffffe7ffbfeff SigIgn: 0000000000000000 SigCgt: 0000000000000000
They are displayed in hex format as 8 bytes. The right most 4 bytes represent stardard signals, the left is Linux real-time signal extension. Each bit in the 8 bytes represents one corresponding signal. If the bits index starts from zero(the right most bit in the above), The corresponding signal is represented by bit[signalValue-1]. An example is that the signal SIGHUP, whose value is 1, is represented the bit 0.
Take the above SigBlk as example, the first two bytes are
0xfeff
The binary format is
1111,1110,1111,1111
It means all signals from 1 to 16 are blocked except the signal 9 (SIGKILL). This is true because SIGKILL cannot be blocked or ignored.