SIGNALNAME(3)

NAME
signalname, signalnumber, signalnext - convert between signal numbers and names

LIBRARY
libc

SYNOPSIS
#include <signal.h>
const char *
signalname(int sig);
int
signalnumber(const char *name);
int
signalnext(int sig);

DESCRIPTION
The signalname() function takes a signal number sig, and returns the name of that signal. The name returned is locale independent, and can be the string representation of one of the signal names from <signal.h> such as SIGHUP, SIGSTOP, SIGKILL, or some similar name, but does not contain the leading “SIG” prefix.

The return value of signalname() is NULL if sig does not represent a valid signal number, or if the signal number given has no name.

The signalnumber() function converts the signal name name to the number corresponding to that signal. The name is handled in a case-insensitive manner. Any leading “SIG” prefix in name is ignored.

This implementation also accepts rtmax[-n] and rtmin[+n] ( where the optional n is a decimal integer between 0 and SIGRTMAX-SIGRTMIN) to refer to the real time signals.

The signalnumber() function returns the signal number, or zero (0) if the name given does not represent a valid signal.

The signalnext() function takes a signal number, and returns the number of the next available bigger signal number. When no higher signal numbers remain, it returns zero (0). The parameter sig can be given as zero (0), to obtain the smallest implemented signal number.

The signalnext() function returns minus one (-1) on error, that is, if the given signal sig is neither a valid signal number nor zero. It returns zero when the input signal number, sig, is the biggest available signal number. Otherwise it returns the signal number of an implemented signal that is larger than sig and such that there are no implemented signals with values between sig and the value returned.

The signalnext() function can also be used to determine if a non-zero signal number is valid or not (0 is always invalid, but cannot be detected as such this way.) Given the non-zero signal number to check as sig, if signalnext() returns anything other than minus one (-1) then sig represents a valid signal number. If the return value is -1 then sig is invalid.

SEE ALSO
kill(1), intro(2), psignal(3), strsignal(3)

HISTORY
The signalname(), signalnext(), and signalnumber() functions first appeared in NetBSD 8.0.