Pseudo-terminal (PTY)

Configuring PTY devices in PASE for i

On AIX, an administrator uses smit to configure the number of available devices of each type. In PASE for i, these devices are configured in the following way:

• For AT&T-style devices, PASE for i supports autoconfiguration. If the first 32 instances are in use and an application tries to open another instance, the CHRSF device is created in the integrated file system automatically, up to the limit of 1024 devices.
• For BSD-style devices, you must create the CHRSF devices manually, using the PASE for i mknod utility. To do this, you need to know the major numbers for the BSD subordinate and BSD primary devices as well as the naming convention. The following example shell script shows how to create additional BSD pseudo-terminal (PTY) devices. It creates them in groups of 16.
  Note: By using the code examples, you agree to the terms of the Code license and disclaimer information.

  #!/QOpenSys/usr/bin/ksh
  
  prefix="pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
  bsd_tty_major=32949
  bsd_pty_major=32948
  
  if [ $# -lt 1 ]
  then
      echo "usage: $(basename $0) ptyN "
      exit 10
  fi
  
  function mkdev {
    if [ ! -e $1 ] 
    then 
      mknod $1 c $2 $3
      chown QSYS $1
      chmod 0666 $1
    fi
  }
  
  while [ "$1" ]
  do
    N=${1##pty}
    if [ "$N" = "$1" -o "$N" = "" -o $N -lt 0 -o $N -gt 36 ]
    then
        echo "skipping: \"$1\": not valid, must be in the form ptyN where: 0 <= N <= 36"
        shift
        continue
    fi
  
    minor=$((N * 16))
    pre=$(expr "$prefix" : ".\{$N\}\(.\)")
  
    echo "creating /dev/[pt]ty${pre}0 - /dev/[pt]ty${pre}f"
    for i in 0 1 2 3 4 5 6 7 8 9 a b c d e f
    do
      echo ".\c"
      mkdev /dev/pty${pre}${i} $bsd_pty_major $minor
      echo ".\c"
      mkdev /dev/tty${pre}${i} $bsd_tty_major $minor
      minor=$((minor + 1))
    done
    echo ""
  
    shift
  done
  
  

For more information about PTY devices, see the AIX Resources Web page.