February 27, 1995 PSIGNAL 3

### NAME

psignal, sys_siglist, sys_signame - system signal messages

### LIBRARY

Standard C Library (libc, -lc)

### SYNOPSIS

```void` psignal(```unsigned sig``, const char *s`)

### DESCRIPTION

The psignal(``) function locates the descriptive message string for the given signal number ```sig` and writes it to the standard error.

If the argument ```s` is non-```NULL` it is written to the standard error file descriptor prior to the message string, immediately followed by a colon and a space. If the signal number is not recognized (sigaction(2)), the string ``Unknown signal'' is produced.

The message strings can be accessed directly using the external array sys_siglist, indexed by recognized signal numbers. The external array sys_signame is used similarly and contains short, upper-case abbreviations for signals which are useful for recognizing signal names in user input. The defined variable ```NSIG` contains a count of the strings in sys_siglist and sys_signame.

### SEE ALSO

sigaction(2), perror(3), setlocale(3), strsignal(3)

### HISTORY

The psignal(``) function appeared in 4.2BSD.