| Signal | Value | Action | Comment |
| or death of controlling process | |||
| SIGINT | 2 | A | Interrupt from keyboard |
| SIGQUIT | 3 | A | Quit from keyboard |
| SIGILL | 4 | A | Illegal Instruction |
| SIGABRT | 6 | C | Abort signal from abort(3) |
| SIGFPE | 8 | C | Floating point exception |
| SIGKILL | 9 | AEF | Kill signal |
| SIGSEGV | 11 | C | Invalid memory reference |
| SIGPIPE | 13 | A | Broken pipe: write to pipe with no readers |
| SIGALRM | 14 | A | Timer signal from alarm(2) |
| SIGTERM | 15 | A | Termination signal |
| SIGUSR1 | 30,10,16 | A | User-defined signal 1 |
| SIGUSR2 | 31,12,17 | A | User-defined signal 2 |
| SIGCHLD | 20,17,18 | B | Child stopped or terminated |
| SIGCONT | 19,18,25 | Continue if stopped | |
| SIGSTOP | 17,19,23 | DEF | Stop process |
| SIGTSTP | 18,20,24 | D | Stop typed at tty |
| SIGTTIN | 21,21,26 | D | tty input for background process |
| SIGTTOU | 22,22,27 | D | tty output for background process |
Next various other signals.
| Signal | Value | Action | Comment |
| SIGIOT | 6 | CG | IOT trap. A synonym for SIGABRT |
| SIGEMT | 7,-,7 | G | |
| SIGBUS | 10,7,10 | AG | Bus error |
| SIGSYS | 12,-,12 | G | Bad argument to routine (SVID) |
| SIGSTKFLT | -,16,- | AG | Stack fault on coprocessor |
| SIGURG | 16,23,21 | BG | Urgent condition on socket (4.2 BSD) |
| SIGIO | 23,29,22 | AG | I/O now possible (4.2 BSD) |
| SIGPOLL | AG | A synonym for SIGIO (System V) | |
| SIGCLD | -,-,18 | G | A synonym for SIGCHLD |
| SIGXCPU | 24,24,30 | AG | CPU time limit exceeded (4.2 BSD) |
| SIGXFSZ | 25,25,31 | AG | File size limit exceeded (4.2 BSD) |
| SIGVTALRM | 26,26,28 | AG | Virtual alarm clock (4.2 BSD) |
| SIGPROF | 27,27,29 | AG | Profile alarm clock |
| SIGPWR | 29,30,19 | AG | Power failure (System V) |
| SIGINFO | 29,-,- | G | A synonym for SIGPWR |
| SIGLOST | -,-,- | AG | File lock lost |
| SIGWINCH | 28,28,20 | BG | Window resize signal (4.3 BSD, Sun) |
| SIGUNUSED | -,31,- | AG | Unused signal |
The letters in the "Action" column have the following meanings: