Figure 4: Common signals and their values

Signal Number   Receive Signals         Description

0               No                      Swapper
10              No                      Waiting for inode
20              No                      Waiting for I/O
21              No                      Waiting for Buffer
26              Yes                     Waiting for pipe
28              Yes                     Waiting for tty input
29              Yes                     Waiting for tty output
30              Yes                     Waiting for exit
40-127          Yes                     User level