Waar kom je dat tegen? In de Linux Kernel Config? Kies in dat geval voor help, daar staat het perfect uitgelegd:
dev/pts filesystem for Unix98 PTYs
You should say Y here if you said Y to "Unix98 PTY support" above.
You'll then get a virtual filesystem which can be mounted on /dev/pts with "mount -t devpts". This, together with the pseudo terminal master multiplexer /dev/ptmx, is used for pseudo terminal support as described in The Open Group's Unix98 standard: in order to acquire a pseudo terminal, a process opens /dev/ptmx; the number of the pseudo terminal is then made available to the process and the pseudo terminal slave can be accessed as /dev/pts/<number>. What was traditionally /dev/ttyp2 will then be /dev/pts/2, for example.
The GNU C library glibc 2.1 contains the requisite support for this mode of operation; you also need client programs that use the Unix98 API.
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