NAME

strsignal — get signal message string

SYNOPSIS

[CX] #include <string.h>

char *strsignal(int signum);

DESCRIPTION

The strsignal() function shall map the signal number in signum to an implementation-defined string and shall return a pointer to it. It shall use the same set of messages as the psignal() function.

The application shall not modify the string returned. The returned pointer might be invalidated or the string content might be overwritten by a subsequent call to strsignal() or setlocale(). The returned pointer might also be invalidated if the calling thread is terminated.

The contents of the message strings returned by strsignal() should be determined by the setting of the LC_MESSAGES category in the current locale.

The implementation shall behave as if no function defined in this standard calls strsignal().

Since no return value is reserved to indicate an error, an application wishing to check for error situations should set errno to 0, then call strsignal(), then check errno.

The strsignal() function need not be thread-safe.

RETURN VALUE

Upon successful completion, strsignal() shall return a pointer to a string. Otherwise, if signum is not a valid signal number, the return value is unspecified.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

If signum is not a valid signal number, some implementations return NULL, while for others the strsignal() function returns a pointer to a string containing an unspecified message denoting an unknown signal. POSIX.1-2024 leaves this return value unspecified.

FUTURE DIRECTIONS

None.

SEE ALSO

psiginfo, setlocale, sig2str

XBD <string.h>

CHANGE HISTORY

First released in Issue 7.

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0609 [75] is applied.

POSIX.1-2008, Technical Corrigendum 2, XSH/TC2-2008/0347 [656] is applied.

Issue 8

Austin Group Defect 1138 is applied, adding sig2str() to the SEE ALSO section.

Austin Group Defect 1474 is applied, changing the NAME section.