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| -rw-r--r-- | share/man/man4/pty.4 | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/share/man/man4/pty.4 b/share/man/man4/pty.4 index 5c6ef10..bb0a88b 100644 --- a/share/man/man4/pty.4 +++ b/share/man/man4/pty.4 @@ -177,12 +177,46 @@ mode, command operations may be detected with a .Xr select 2 for exceptional conditions. .El + +There is currently two pty systems available : the original BSD pty, and a +SysVR4 pts-like implementation. +You can switch between the two implementations by setting the +.Va kern.pts.enable +sysctl. Setting it to 0 will use the BSD pty, to non-zero the pts +implementation. It defaults to 0. +You can set the maximum number of ptys which can be allocated at the same time +with the +.Va kern.pts.max +sysctl. It defaults to 1000. +It is not recommanded to use more than 1000 pseudo-terminals, as all software +which use +.Xr utmp 5 +won't be able to handle pseudo-terminals with number superior to 999. + +The pts implementation also supports the +.Dv TIOCGPTN +.Xr ioctl 2 +call, which takes a pointer to an unsigned int as a parameter and provides the +number of the pty. + .Sh FILES .Bl -tag -width /dev/tty[p-sP-S][0-9a-v]x -compact +The files used by the BSD pseudo terminals implementation are : .It Pa /dev/pty[p-sP-S][0-9a-v] master pseudo terminals .It Pa /dev/tty[p-sP-S][0-9a-v] slave pseudo terminals + +.El +The files used by the pts implementation are : +.Bl -tag -width /dev/pts/[num]x -compact +.It Pa /dev/ptmx +control device, returns a file descriptor to a new master pseudo terminal +when opened. +.It Pa /dev/pty[num] +master pseudo terminals +.It Pa /dev/pts/[num] +slave pseudo terminals .El .Sh DIAGNOSTICS None. |
