SIGTTOU
From Wikipedia, the free encyclopedia
| Description: | Tty output for background process |
|---|---|
| Default action: | Suspends the process |
| SA_SIGINFO macros | |
| None | |
On POSIX-compliant platforms, SIGTTOU is the signal thrown by computer programs that attempt to write to the tty while in the background. The symbolic constant for SIGTTOU is defined in the header file signal.h. Symbolic signal names are used because signal numbers can vary across platforms.
[edit] Etymology
SIG is a common prefix for signal names. TT stands for tty, an abbreviation for teletypewriter, an archaic type of computer terminal. OU refers to output.
[edit] Usage
SIGTTOU may be sent to a background process that attempts to write to its controlling terminal. Typically this applies to processes under job control; daemons do not have controlling terminals. Background processes thus suspended can be placed into the foreground to write output by the shell.
| POSIX Signals |
| SIGABRT | SIGALRM | SIGFPE | SIGHUP | SIGILL | SIGINT | SIGKILL | SIGPIPE | SIGQUIT | SIGSEGV | SIGTERM | SIGUSR1 | SIGUSR2 | SIGCHLD | SIGCONT | SIGSTOP | SIGTSTP | SIGTTIN | SIGTTOU | SIGBUS | SIGPOLL | SIGPROF | SIGSYS | SIGTRAP | SIGURG | SIGVTALRM | SIGXCPU | SIGXFSZ | Realtime Signals are user definable—SIGRTMIN+n through SIGRTMAX. |
| Common non-POSIX signals and synonyms |
| SIGIOT | SIGEMT | SIGSTKFLT | SIGIO | SIGCLD | SIGINFO | SIGPWR (SIGINFO) | SIGLOST | SIGWINCH | SIGUNUSED |
