diff --git a/man7/signal.7 b/man7/signal.7 index b4e122e71..5a1bdc8c4 100644 --- a/man7/signal.7 +++ b/man7/signal.7 @@ -55,7 +55,7 @@ Each signal has a current which determines how the process behaves when it is delivered the signal. .PP -The entries in the "Action" column of the tables below specify +The entries in the "Action" column of the table below specify the default disposition for each signal, as follows: .IP Term Default action is to terminate the process. @@ -221,41 +221,59 @@ the pending signal set is preserved across an .BR execve (2). .SS Standard signals Linux supports the standard signals listed below. -Several signal numbers -are architecture-dependent, as indicated in the "Value" column. -Where four values are given, -the first one is valid for x86, arm, and most other architectures, -the second one for alpha and sparc, -the third one for mips, and the last one for parisc. -A dash (\-) denotes that a signal is absent on the corresponding architecture. -.PP -First the signals described in the original POSIX.1-1990 standard. +The second column of the table indicates which standard (if any) +specified the signal: "P1990" indicates that the signal is described +in the original POSIX.1-1990 standard; +"P2001" indicates that the signal was added in SUSv2 and POSIX.1-2001. .TS l c c l ____ lB c c l. Signal Standard Action Comment +SIGABRT P1990 Core Abort signal from \fBabort\fP(3) +SIGALRM P1990 Term Timer signal from \fBalarm\fP(2) +SIGBUS P2001 Core Bus error (bad memory access) +SIGCHLD P1990 Ign Child stopped or terminated +SIGCLD \- Ign A synonym for \fBSIGCHLD\fP +SIGCONT P1990 Cont Continue if stopped +SIGEMT \- Term Emulator trap +SIGFPE P1990 Core Floating-point exception SIGHUP P1990 Term Hangup detected on controlling terminal or death of controlling process -SIGINT P1990 Term Interrupt from keyboard -SIGQUIT P1990 Core Quit from keyboard SIGILL P1990 Core Illegal Instruction -SIGABRT P1990 Core Abort signal from \fBabort\fP(3) -SIGFPE P1990 Core Floating-point exception +SIGINFO \- A synonym for \fBSIGPWR\fP +SIGINT P1990 Term Interrupt from keyboard +SIGIO \- Term I/O now possible (4.2BSD) +SIGIOT \- Core IOT trap. A synonym for \fBSIGABRT\fP SIGKILL P1990 Term Kill signal -SIGSEGV P1990 Core Invalid memory reference +SIGLOST \- Term File lock lost (unused) SIGPIPE P1990 Term Broken pipe: write to pipe with no readers; see \fBpipe\fP(7) -SIGALRM P1990 Term Timer signal from \fBalarm\fP(2) -SIGTERM P1990 Term Termination signal -SIGUSR1 P1990 Term User-defined signal 1 -SIGUSR2 P1990 Term User-defined signal 2 -SIGCHLD P1990 Ign Child stopped or terminated -SIGCONT P1990 Cont Continue if stopped +SIGPOLL P2001 Term Pollable event (Sys V). + Synonym for \fBSIGIO\fP +SIGPROF P2001 Term Profiling timer expired +SIGPWR \- Term Power failure (System V) +SIGQUIT P1990 Core Quit from keyboard +SIGSEGV P1990 Core Invalid memory reference +SIGSTKFLT \- Term Stack fault on coprocessor (unused) SIGSTOP P1990 Stop Stop process SIGTSTP P1990 Stop Stop typed at terminal +SIGSYS P2001 Core Bad system call (SVr4); + see also \fBseccomp\fP(2) +SIGTERM P1990 Term Termination signal +SIGTRAP P2001 Core Trace/breakpoint trap SIGTTIN P1990 Stop Terminal input for background process SIGTTOU P1990 Stop Terminal output for background process +SIGUNUSED \- Core Synonymous with \fBSIGSYS\fP +SIGURG P2001 Ign Urgent condition on socket (4.2BSD) +SIGUSR1 P1990 Term User-defined signal 1 +SIGUSR2 P1990 Term User-defined signal 2 +SIGVTALRM P2001 Term Virtual alarm clock (4.2BSD) +SIGXCPU P2001 Core CPU time limit exceeded (4.2BSD); + see \fBsetrlimit\fP(2) +SIGXFSZ P2001 Core File size limit exceeded (4.2BSD); + see \fBsetrlimit\fP(2) +SIGWINCH \- Ign Window resize signal (4.3BSD, Sun) .TE .PP The signals @@ -264,28 +282,6 @@ and .B SIGSTOP cannot be caught, blocked, or ignored. .PP -Next the signals not in the POSIX.1-1990 standard but described in -SUSv2 and POSIX.1-2001. -.TS -l c c l -____ -lB c c l. -Signal Standard Action Comment -SIGBUS P2001 Core Bus error (bad memory access) -SIGPOLL P2001 Term Pollable event (Sys V). - Synonym for \fBSIGIO\fP -SIGPROF P2001 Term Profiling timer expired -SIGSYS P2001 Core Bad system call (SVr4); - see also \fBseccomp\fP(2) -SIGTRAP P2001 Core Trace/breakpoint trap -SIGURG P2001 Ign Urgent condition on socket (4.2BSD) -SIGVTALRM P2001 Term Virtual alarm clock (4.2BSD) -SIGXCPU P2001 Core CPU time limit exceeded (4.2BSD); - see \fBsetrlimit\fP(2) -SIGXFSZ P2001 Core File size limit exceeded (4.2BSD); - see \fBsetrlimit\fP(2) -.TE -.PP Up to and including Linux 2.2, the default behavior for .BR SIGSYS ", " SIGXCPU ", " SIGXFSZ ", " and (on architectures other than SPARC and MIPS) @@ -297,31 +293,6 @@ is to terminate the process without a core dump.) Linux 2.4 conforms to the POSIX.1-2001 requirements for these signals, terminating the process with a core dump. .PP -Next various other signals. -.TS -l c c l -____ -lB c c l. -Signal Standard Action Comment -SIGIOT \- Core IOT trap. A synonym for \fBSIGABRT\fP -SIGEMT \- Term Emulator trap -SIGSTKFLT \- Term Stack fault on coprocessor (unused) -SIGIO \- Term I/O now possible (4.2BSD) -SIGCLD \- Ign A synonym for \fBSIGCHLD\fP -SIGPWR \- Term Power failure (System V) -SIGINFO \- A synonym for \fBSIGPWR\fP -SIGLOST \- Term File lock lost (unused) -SIGWINCH \- Ign Window resize signal (4.3BSD, Sun) -SIGUNUSED \- Core Synonymous with \fBSIGSYS\fP -.TE -.PP -(Signal 29 is -.B SIGINFO -/ -.B SIGPWR -on an alpha but -.B SIGLOST -on a sparc.) .PP .B SIGEMT is not specified in POSIX.1-2001, but nevertheless appears @@ -336,15 +307,7 @@ by default on those other UNIX systems where it appears. .B SIGIO (which is not specified in POSIX.1-2001) is ignored by default on several other UNIX systems. -.PP -Where defined, -.B SIGUNUSED -is synonymous with -.BR SIGSYS . -Since glibc 2.26, -.B SIGUNUSED -is no longer defined on any architecture. -.PP +.\" .SS Signal numbering for standard signals The numeric value for each signal is given in the table below. As shown in the table, many signals have different numeric values