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Diffstat (limited to 'share/man/man4/snp.4')
-rw-r--r-- | share/man/man4/snp.4 | 32 |
1 files changed, 22 insertions, 10 deletions
diff --git a/share/man/man4/snp.4 b/share/man/man4/snp.4 index 42aab41..9a61000 100644 --- a/share/man/man4/snp.4 +++ b/share/man/man4/snp.4 @@ -16,33 +16,45 @@ .Ft int .Fn ioctl fd FIONREAD &result .Sh DESCRIPTION -/dev/snp? are snoop devices which allow users to attach to any tty +.Pa /dev/snp? +are snoop devices which allow users to attach to any tty and watch activities on it. The kernel must be compiled with .Cd "device snp" , or the .Nm -device must be loaded, +module must be loaded, for these devices to be available. .Pp To associate a given .Nm device with a tty to be observed, open the .Nm -device and then use the SNPSTTY ioctl. -The argument passed to the ioctl is the address of a variable of type -dev_t. -To detach the snp device from a tty use a pointer to a value of (dev_t)-1. +device and then use the +.Dv SNPSTTY +ioctl. +The argument passed to the +.Xr ioctl 2 +is the address of a variable of type +.Vt dev_t . +To detach the +.Nm +device from a tty use a pointer to a value of +.Po Vt dev_t Pc Ns \-1 . .Pp -The SNPGTTY ioctl returns information about the current tty attached to +The +.Dv SNPGTTY +ioctl returns information about the current tty attached to the open .Nm device. .Pp -The FIONREAD ioctl returns a positive value equal to the number of characters +The +.Dv FIONREAD +ioctl returns a positive value equal to the number of characters in a read buffer. Special values defined are: -.Bl -tag -width SNP_TTYCLOSE +.Bl -tag -width ".Dv SNP_TTYCLOSE" .It Dv SNP_OFLOW device overflow occurred, device detached. .It Dv SNP_TTYCLOSE @@ -61,7 +73,7 @@ and detached. Caveat emptor! This manual page is horribly stale and wildly inaccurate in some places. .Pp -While in line mode, user input can't be seen. +While in line mode, user input cannot be seen. No signals may be sent to the observed tty. .Sh AUTHORS .An Ugen J.S. Antsilevich Aq ugen@NetVision.net.il |