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diff --git a/man3p/signal.3p b/man3p/signal.3p new file mode 100644 index 000000000..05d9f55cf --- /dev/null +++ b/man3p/signal.3p @@ -0,0 +1,151 @@ +.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved +.TH "SIGNAL" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" +.\" signal +.SH NAME +signal \- signal management +.SH SYNOPSIS +.LP +\fB#include <signal.h> +.br +.sp +void (*signal(int\fP \fIsig\fP\fB, void (*\fP\fIfunc\fP\fB)(int)))(int); +.br +\fP +.SH DESCRIPTION +.LP +Use +of this function is unspecified in a multi-threaded process. +.LP +The \fIsignal\fP() function chooses one of three ways in which receipt +of the signal number \fIsig\fP is to be subsequently +handled. If the value of \fIfunc\fP is SIG_DFL, default handling for +that signal shall occur. If the value of \fIfunc\fP is +SIG_IGN, the signal shall be ignored. Otherwise, the application shall +ensure that \fIfunc\fP points to a function to be called +when that signal occurs. An invocation of such a function because +of a signal, or (recursively) of any further functions called by +that invocation (other than functions in the standard library), is +called a "signal handler". +.LP +When a signal occurs, and \fIfunc\fP points to a function, it is implementation-defined +whether the equivalent of a: +.sp +.RS +.nf + +\fBsignal(\fP\fIsig\fP\fB, SIG_DFL); +\fP +.fi +.RE +.LP +is executed or the implementation prevents some implementation-defined +set of signals (at least including \fIsig\fP) from +occurring until the current signal handling has completed. (If the +value of \fIsig\fP is SIGILL, the implementation may +alternatively define that no action is taken.) Next the equivalent +of: +.sp +.RS +.nf + +\fB(*func)(sig); +\fP +.fi +.RE +.LP +is executed. If and when the function returns, if the value of \fIsig\fP +was SIGFPE, SIGILL, or SIGSEGV or any other +implementation-defined value corresponding to a computational exception, +the behavior is undefined. Otherwise, the program shall +resume execution at the point it was interrupted. If the signal occurs +as the result of calling the \fIabort\fP(), \fIraise\fP(), \fIkill\fP(), +\fIpthread_kill\fP(), or \fIsigqueue\fP() function, the +signal handler shall not call the \fIraise\fP() function. +.LP +If the signal occurs other than as the result of calling \fIabort\fP(), +\fIraise\fP(), \fIkill\fP(), \fIpthread_kill\fP(), or \fIsigqueue\fP(), +\ the behavior is undefined if the signal handler refers to any +object with static storage duration other than by assigning a value +to an object declared as volatile \fBsig_atomic_t\fP, or if +the signal handler calls any function in the standard library other +than one of the functions listed in \fISignal Concepts\fP . Furthermore, +if such a call fails, the value of \fIerrno\fP is +unspecified. +.LP +At program start-up, the equivalent of: +.sp +.RS +.nf + +\fBsignal(\fP\fIsig\fP\fB, SIG_IGN); +\fP +.fi +.RE +.LP +is executed for some signals, and the equivalent of: +.sp +.RS +.nf + +\fBsignal(\fP\fIsig\fP\fB, SIG_DFL); +\fP +.fi +.RE +.LP +is executed for all other signals \ (see \fIexec\fP). +.SH RETURN VALUE +.LP +If the request can be honored, \fIsignal\fP() shall return the value +of \fIfunc\fP for the most recent call to \fIsignal\fP() +for the specified signal \fIsig\fP. Otherwise, SIG_ERR shall be returned +and a positive value shall be stored in \fIerrno\fP. +.SH ERRORS +.LP +The \fIsignal\fP() function shall fail if: +.TP 7 +.B EINVAL +The \fIsig\fP argument is not a valid signal number or an attempt +is made to catch a signal that cannot be caught or ignore a +signal that cannot be ignored. +.sp +.LP +The \fIsignal\fP() function may fail if: +.TP 7 +.B EINVAL +An +attempt was made to set the action to SIG_DFL for a signal that cannot +be caught or ignored (or both). +.sp +.LP +\fIThe following sections are informative.\fP +.SH EXAMPLES +.LP +None. +.SH APPLICATION USAGE +.LP +The \fIsigaction\fP() function provides a more comprehensive and reliable +mechanism +for controlling signals; new applications should use \fIsigaction\fP() +rather than +\fIsignal\fP(). +.SH RATIONALE +.LP +None. +.SH FUTURE DIRECTIONS +.LP +None. +.SH SEE ALSO +.LP +\fISignal Concepts\fP , \fIexec\fP() , \fIpause\fP() , \fIsigaction\fP() +, \fIsigsuspend\fP() , \fIwaitid\fP() , the Base Definitions volume +of IEEE\ Std\ 1003.1-2001, \fI<signal.h>\fP +.SH COPYRIGHT +Portions of this text are reprinted and reproduced in electronic form +from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology +-- Portable Operating System Interface (POSIX), The Open Group Base +Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of +Electrical and Electronics Engineers, Inc and The Open Group. In the +event of any discrepancy between this version and the original IEEE and +The Open Group Standard, the original IEEE and The Open Group Standard +is the referee document. The original Standard can be obtained online at +http://www.opengroup.org/unix/online.html . |