SIGTTIN

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SIGTTIN
Description: Tty input for background process
Default action: Suspends the process
SA_SIGINFO macros
None

On POSIX-compliant platforms, SIGTTIN is the signal thrown by computer programs that attempt to read from the tty while in the background. The symbolic constant for SIGTTIN 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 is for tty, an abbreviation for teletypewriter, an archaic type of computer terminal. IN refers to input.

[edit] Usage

SIGTTIN may be sent to a background process that attempts to read from 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 accept input 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