ttysrch(4)							   File Formats 							ttysrch(4)

NAME

       ttysrch - directory search list for ttyname

DESCRIPTION

       ttysrch	is  an optional file that is used by the ttyname library routine. This file contains the names of directories in /dev that contain
       terminal and terminal-related device files. The purpose of this file is to improve the performance of ttyname by indicating which subdirec-
       tories  in  /dev contain terminal-related device files and should be searched first. These subdirectory names must appear on separate lines
       and must begin with /dev. Those path names that do not begin with /dev will be ignored and a warning will be sent  to  the  console.  Blank
       lines  (lines containing only white space) and lines beginning with the comment character "#" will be ignored. For each file listed (except
       for the special entry /dev), ttyname will recursively search through subdirectories looking for a match. If /dev  appears  in  the  ttysrch
       file, the /dev directory itself will be searched but there will not be a recursive search through its subdirectories.

       When  ttyname searches through the device files, it tries to find a file whose major/minor device number, file system identifier, and inode
       number match that of the file descriptor it was given as an argument. If a match is  not  found,  it  will  settle  for	a  match  of  just
       major/minor  device  and  file  system identifier, if one can be found. However, if the file descriptor is associated with a cloned device,
       this algorithm does not work efficiently because the inode number  of the device file associated with a clonable device	will  never  match
       the  inode  number of the file descriptor that was returned by the open of that clonable device. To help with these situations, entries can
       be put into the /etc/ttysrch file to improve performance when cloned devices are used as terminals  on a system (for  example,  for  remote
       login).	However, this is only useful if the minor devices related to a cloned device are put into a subdirectory. (It is important to note
       that device files need not exist for cloned devices and if that is the case, ttyname will eventually fail.) An  optional  second  field	is
       used  in  the  /etc/ttysrch  file  to  indicate the matching criteria. This field is separated by white space (any combination of blanks or
       tabs). The letter M means major/minor device number, F means file system identifier, and I means inode number. If this field is not  speci-
       fied  for  an  entry,  the default is MFI which means try to match on all three. For cloned devices the field should be MF, which indicates
       that it is not necessary to match on the inode number.

       Without the /etc/ttysrch file, ttyname will search the /dev directory by first looking in the directories /dev/term, /dev/pts, and /dev/xt.
       If a system has terminal devices installed in directories other than these, it may help performance if the ttysrch file is created and con-
       tains that list of directories.

EXAMPLES

       Example 1: A sample display of /etc/ttysrch command.

       A sample /etc/ttysrch file follows:

       /dev/term     MFI
       /dev/pts      MFI
       /dev/xt	     MFI
       /dev/slan     MF

       This file tells	ttyname that it should first search through those directories listed  and that when searching through the /dev/slan direc-
       tory,  if a file is encountered whose major/minor devices and file system identifier match that of the file descriptor argument to ttyname,
       this device name should be considered a match.

FILES

       /etc/ttysrch

SEE ALSO

       ttyname(3C)

SunOS 5.10							    23 Feb 1994 							ttysrch(4)