| Signal name | Value | Action | Comment |
| SIGHUP | 1 | A | Hangup detected |
| SIGINT | 2 | A | Interrupt from keyboard |
| SIGQUIT | 3 | A | Quit from keyboard |
| SIGILL | 4 | A | Illegal Instruction |
| SIGTRAP | 5 | CG | Trace/breakpoint trap |
| SIGABRT | 6 | C | Abort |
| SIGUNUSED | 7 | AG | Unused signal |
| SIGFPE | 8 | C | Floating point exception |
| SIGKILL | 9 | AEF | Termination signal |
| SIGUSR1 | 10 | A | User-defined signal 1 |
| SIGSEGV | 11 | C | Invalid memory reference |
| SIGUSR2 | 12 | A | User-defined signal 2 |
| SIGPIPE | 13 | A | Write to pipe with no readers |
| SIGALRM | 14 | A | Timer signal from alarm(1). |
| SIGTERM | 15 | A | Termination signal |
| SIGSTKFLT | 16 | AG | Stack fault on coprocessor |
| SIGCHLD | 17 | B | Child terminated |
| SIGCONT | 18 | Continue if stopped | |
| SIGTSTOP | 19 | DEF | Stop process |
| SIGTSTP | 20 | D | Stop typed at tty |
| SIGTTIN | 21 | D | tty input for background process |
| SIGTTOU | 22 | D | tty output for background process |
| SIGIO | 23 | AG | I/O error |
| SIGXCPU | 24 | AG | CPU time limit exceeded |
| SIGXFSZ | 25 | AG | File size limit exceeded |
| SIGVTALRM | 26 | AG | Virtual time alarm (???) |
| SIGPROF | 27 | AG | Profile signal |
| SIGWINCH | 29 | BG | Window resize signal |
The letters in the "Action" column have the following meanings: