    This file lists major changes which accompany each new release.

    Version 1.6.1:

      This is primarily a minor bug-fix release.

      One added feature is the ability to call gl_normal_io() from
      callbacks registered by gl_watch_fd() and
      gl_inactivity_timeout(). This allows these callbacks to cleanly
      suspend line editing before either reading from the terminal, or
      writing to the terminal; and then subsequently causes the input line
      to be automatically redisplayed, and line-editing to be resumed by
      gl_get_line(), as soon as the callback returns.

      Another minor change is that if the terminal type specified in the
      TERM environment variable is set to "dumb", gl_get_line() now treats
      the terminal as though it were a non-interactive stream, rather than
      treating it as a VT100-compatible terminal. This means that it
      doesn't either prompt for input, or perform any command-line
      editing, even when it really is interacting with a terminal. This is
      aimed at the rare situation where a third-pary program that connects
      to libtecla through an embedded pseudo-terminal, needs to be forced
      to behave as though it weren't talking to a terminal, in order that
      it be useable in non-interactive scripts.

      Note that in the previous release, the optional configuration
      function, gl_tty_signals(), was incorrectly swapping the suspend and
      terminal signal handlers before installing them.

      A configuration problem that prevented select() from being used
      under MacOS X, has been fixed.

      Although not documented in the man page, it was meant to be possible
      to take the input line that one call to gl_get_line() returned, and
      ask the next call to gl_get_line() to present it back to the user
      for re-editing, simply by passing the pointer returned by one call
      to gl_get_line() as the start_line argument of the next call to
      gl_get_line(). This feature unfortunately stopped working in 1.6.0,
      so this release restores it, and officially documents it in the man
      page documentation of gl_get_line().

      In the previous version of the library, calling gl_terminal_size()
      on a system without SIGWINCH support, would crash the
      application. This has been fixed.

      Libtecla now apparently compiles cleanly under IRIX.

    Version 1.6.0:

      This release is primarily a bug-fix release. However there are also
      four new functions, so the minor version number has been
      incremented to reflect this.

      Two of the new functions are gl_automatic_history() and
      gl_append_history(). The former of these functions allows the
      application to tell gl_get_line() not to automatically archive
      entered lines in the history list. The second of these functions
      allows the application to explicitly append a line to the history
      list. Thus together, these two functions allow the calling
      application to take over control of what is placed in the history
      list.

      The third new function is gl_query_char(), which prompts the user
      for a single character reply, which the user can then type without
      having to hit return to enter it. Unless echoing is disabled, the
      character that is entered is then displayed after the prompt,
      and a newline is started.

      Finally, the 4th new function is gl_read_char(), which also reads
      a single character from the user, but doesn't prompt the user, write
      anything to the terminal, or disturb any partially entered input
      line. It is thus safe to call this function not only from between
      calls to gl_get_line(), but also from application callback
      functions, even if gl_normal_io() hasn't been called.

      When using the history-search-backwards or history-search-forwards
      actions, if the search prefix that the user typed, contains any of
      the *,? or [ globbing characters, it is now treated as a glob
      pattern to be matched against historical lines, instead of a simple
      prefix.

      I have added a --without-file-system option to the configure
      script. This is intended for use in embedded systems that either
      don't have filesystems, or where the file-system code in libtecla is
      seen as unwanted bloat. See the INSTALL document for details.

      Similarly, I also added a --without-file-actions option to the
      configure script. This allows the application author/installer to
      prevent users of gl_get_line() from accessing the filesystem with
      the builtin actions of gl_get_line(). It does this by removing a
      number of action functions, such as expand-filename, and list-glob,
      and by changing the default behavior of other actions, such as
      complete-word and list-or-eof, to show no completions.

      Now to the bugs that have been fixed. Version 1.5.0 had a lot of big
      internal changes, so there are a number of bugs that needed to be
      fixed.  There was a bug which caused a crash if gl_load_history()
      was called multiple times. There was another bug which caused a
      prompt not to be displayed on the next line after switching from
      reading input from a file to reading from the terminal. Also, in
      tecla configuration files, backslash escaped characters within
      key-binding key-sequences weren't being escaped. Thus ^\\ got
      interpretted as a control-\ followed by a \ character instead of as
      a control-\. There was a bug in the history recall mechanism which
      caused the search prefix to be forgotten in certain complicated
      usage scenarios. There was a minor memory leak in the
      gl_configure_getline() function. Finally, if gl_get_line() was
      aborted by a signal, or any other abnormal event, the value of errno
      which originally indicated what had happened, got zeroed by the
      code that restored the terminal to a usable state. Thus the
      application couldn't figure out what had caused the error, apart
      from by looking at gl_return_status(). All of these bugs have been
      fixed.

      In the Makefile, there were a number of places where install-sh was
      invoked without a path prefix. This has now been remedied.

      A fully functional workaround for a bug in Solaris' terminal I/O
      code has also been implemented. This bug, which only manifested
      itself in libtecla's uncommonly used non-blocking server I/O mode,
      caused characters entered while in normal I/O mode, between calls to
      gl_get_line() to be invisible to the next call to gl_get_line(),
      until the user typed at least one more key after raw terminal mode
      was restored.

      The Gnu autoconf config.guess and config.sub scripts have been
      updated to their latest versions. Apparently the old versions that I
      was previously using were too old to know about certain BSD ports.

    Version 1.5.0:

      This release includes several major new features for those using
      gl_get_line(), shared library support in Darwin, better cross
      compilation support, and various minor bug fixes.

      The biggest new feature is the option of a non-blocking I/O mode, in
      which gl_get_line() can safely be called from an application's
      external event-loop to incrementally read input lines from the user.
      This feature is documented in the gl_io_mode(3) man page.

      In addition, there is now support for the definition of additional
      word-completion action functions, which can then be bound to
      different keys. See the documentation of the gl_completion_action()
      function in the gl_get_line(3) man page.

      Externally defined action functions can also be defined, although
      presently they don't have write access to the input line, so they
      are restricted to operations that display information text to the
      terminal, or modify the environment of the calling application in
      some way. See the documentation of the gl_register_action() function
      in the gl_get_line(3) man page.

      Some of the non-blocking I/O support functions can also be used for
      improved signal handling in the normal blocking mode. In particular,
      the gl_list_signals() and gl_catch_blocked() functions make it
      easier to write reliable signal handling around gl_get_line(). The
      new "RELIABLE SIGNAL HANDLING" section of the gl_get_line(3) man
      page is intended as an introduction to this subject.

      Programs can now clear the terminal between calls to gl_get_line(),
      by calling the new gl_erase_terminal() function.

      The gl_display_text() function, now used in the demos to display
      introductory banners, is provided for formatting text according to
      the width of the terminal.

      It is now possible to install inactivity timeout callbacks in
      gl_get_line(), using the new gl_inactivity_timeout() function.

      The new gl_set_term_size() function allows the application to
      explicitly set the terminal size, for cases, such as when one is
      using a terminal at the end of a serial lineq, where the terminal
      driver doesn't send the process a SIGWINCH when the terminal size
      changes.

      The new gl_bind_keyseq() function provides a convenient
      alternative to gl_configure_getline(), for binding or unbinding
      one key-sequence at a time.

      gl_get_line()s signal handling, file-descriptor event-handling,
      inactivity-timeout handling and server-mode non-blocking I/O
      features now not only work when input is coming from a terminal, but
      now also work when input is coming from non-interactive streams,
      such as files and pipes.

      The history implementation has been re-written to make it more
      efficient and easier to modify. The biggest user-level change is
      that when recalling history lines using a search prefix, the same
      line is no longer returned more than once in a row.  Previously this
      duplicate elimination only worked when one was recalling a line
      without specifying a search prefix, and this was naively performed
      by preventing neighboring duplicates from existing in the history
      list, rather than by skipping duplicates at search time.

      In previous versions of the library, when gl_get_line() and its
      associated public functions detected invalid arguments, or couldn't
      allocate memory, etc, error messages were written to stderr. This
      isn't appropriate for library functions, so instead of writing such
      messages to stderr, these messages are now recorded in buffers
      within the affected GetLine object. The latest error message can
      then subsequently be queried by calling gl_error_message(). The use
      of errno has also been expanded, and a new function called
      gl_return_status() has been provided to expand on the cause of the
      last return from gl_get_line().

      User level usage and configuration information has now been split
      out of the gl_get_line(3) man page into a separate tecla(7) man
      page. The enhance(3) man page has also been renamed to enhance(1).

      When expanding "~/", gl_get_line() now checks for, and returns the
      value of the HOME environment variable, if it exists, in preference
      to looking up the directory of the current user in the password
      file.

      When the terminal was resized to a narrower width, previous versions
      of gl_get_line() would redraw the line higher up the terminal. This
      bug has been fixed. A bug in history recall has also been fixed, in
      which an error message was being generated if one attempted to
      recall a line while the cursor was at the end of the longest
      possible input line. A more serious bug, in which callbacks
      registered by gl_watch_fd() weren't being called for write-events,
      has also been fixed. Finally, a few minor fixes have been made to
      improve support under QNX and Mac OS X.

      Beware that in this release, much of the underlying code has
      undergone some radical re-work, so although backwards compatibility
      of all documented features has been preserved, there may be some
      lingering bugs that could break existing programs.  So, if you plan
      to use this version in production code, please test it as far as
      possible within your application before releasing it to your
      clients, and as always, please report any unexpected behavior.

    Version 1.4.1:

      This is a maintenance release. It includes minor changes to support
      Mac OS X (Darwin), the QNX real-time operating system, and Cygwin
      under Windows. It also fixes an oversight that was preventing the
      tab key from inserting tab characters when users unbound the
      complete-word action from it.

    Version 1.4.0:

      The contents of the history list can now be saved and restored with
      the new gl_save_history() and gl_load_history() functions.

      Event handlers can now be registered to watch for and respond to I/O
      on arbitrary file descriptors while gl_get_line() is waiting for
      terminal input from the user. See the gl_get_line(3) man page
      for details on gl_watch_fd().

      As an optional alternative to getting configuration information only
      from ~/.teclarc, the new gl_configure_getline() function allows
      configuration commands to be taken from any of, a string, a
      specified application-specific file, and/or a specified
      user-specific file. See the gl_get_line(3) man page for details.

      The version number of the library can now be queried using the
      libtecla_version() function. See the libtecla(3) man page.

      The new gl_group_history() function allows applications to group
      different types of input line in the history buffer, and arrange for
      only members of the appropriate group to be recalled on a given call
      to gl_get_line(). See the gl_get_line(3) man page.

      The new gl_show_history() function displays the current history list
      to a given stdio output stream. See the gl_get_line(3) man page.

      new_GetLine() now allows you to specify a history buffer size of
      zero, thus requesting that no history buffer be allocated. You can
      subsequently resize or delete the history buffer at any time, by
      calling gl_resize_history(), limit the number of lines that are
      allowed in the buffer by calling gl_limit_history(), clear either
      all history lines from the history list, or just the history lines
      that are associated with the current history group, by calling
      gl_clear_history, and toggle the history mechanism on and off by
      calling gl_toggle_history().

      The new gl_terminal_size() function can be used to query the
      current terminal size. It can also be used to supply a default
      terminal size on systems where no mechanism is available for
      looking up the size.

      The contents and configuration of the history list can now be
      obtained by the calling application, by calling the new
      gl_lookup_history(), gl_state_of_history(), gl_range_of_history()
      and gl_size_of_history() functions. See the gl_get_line(3) man page.

      Echoing of the input line as it is typed, can now be turned on and
      off via the new gl_echo_mode() function. While echoing is disabled,
      newly entered input lines are omitted from the history list.  See
      the gl_get_line(3) man page.

      While the default remains to display the prompt string literally,
      the new gl_prompt_style() function can be used to enable text
      attribute formatting directives in prompt strings, such as
      underlining, bold font, and highlighting directives.

      Signal handling in gl_get_line() is now customizable. The default
      signal handling behavior remains essentially the same, except that
      the SIGTSTP, SIGTTIN and SIGTTOU are now forwarded to the
      corresponding signal handler of the calling program, instead of
      causing a SIGSTOP to be sent to the application.  It is now possible
      to remove signals from the list that are trapped by gl_get_line(),
      as well as add new signals to this list. The signal and terminal
      environments in which the signal handler of the calling program is
      invoked, and what gl_get_line() does after the signal handler
      returns, is now customizable on a per signal basis. You can now also
      query the last signal that was caught by gl_get_line(). This is
      useful when gl_get_line() aborts with errno=EINTR, and you need to
      know which signal caused it to abort.

      Key-sequences bound to action functions can now start with printable
      characters. Previously only keysequences starting with control or
      meta characters were permitted.

      gl_get_line() is now 8-bit clean. If the calling program has
      correctly called setlocale(LC_CTYPE,""), then the user can select an
      alternate locale by setting the standard LC_CTYPE, LC_ALL, or LANG
      environment variables, and international characters can then be
      entered directly, either by using a non-US keyboard, or by using a
      compose key on a standard US keyboard. Note that in locales in which
      meta characters become printable, meta characters no longer match
      M-c bindings, which then have to be entered using their escape-c
      equivalents.  Fortunately most modern terminal emulators either
      output the escape-c version by default when the meta key is used, or
      can be configured to do so (see the gl_get_line(3) man page), so in
      most cases you can continue to use the meta key.

      Completion callback functions can now tell gl_get_line() to return
      the input line immediately after a successful tab completion, simply
      by setting the last character of the optional continuation suffix to
      a newline character (ie. in the call to cpl_add_completion()).

      It is now safe to create and use multiple GetLine objects, albeit
      still only from a single thread. In conjunction with the new
      gl_configure_getline() function, this optionally allows multiple
      GetLine objects with different bindings to be used to implement
      different input modes.

      The edit-mode configuration command now accepts the argument,
      none. This tells gl_get_line() to revert to using just the native
      line editing facilities provided by the terminal driver. This could
      be used if the termcap or terminfo entry of the host terminal were
      badly corrupted.

      Application callback functions invoked by gl_get_line() can now
      change the displayed prompt using the gl_replace_prompt() function.

      Their is now an optional program distributed with the library. This
      is a beta release of a program which adds tecla command-line editing
      to virtually any third party application without the application
      needing to be linked to the library. See the enhance(3) man page for
      further details. Although built and installed by default, the
      INSTALL document explains how to prevent this.

      The INSTALL document now explains how you can stop the demo programs
      from being built and installed.

      NetBSD/termcap fixes. Mike MacFaden reported two problems that he
      saw when compiling libtecla under NetBSD. Both cases were related to
      the use of termcap.  Most systems use terminfo, so this problem has
      gone unnoticed until now, and won't have affected the grand majority
      of users.  The configure script had a bug which prevented the check
      for CPP working properly, and getline.c wouldn't compile due to an
      undeclared variable when USE_TERMCAP was defined. Both problems have
      now been fixed. Note that if you successfully compiled version
      1.3.3, this problem didn't affect you.

      An unfortunate and undocumented binding of the key-sequence M-O was
      shadowing the arrow-key bindings on systems that use ^[OA etc. I
      have removed this binding (the documented lower case M-o binding
      remains bound). Under the KDE konsole terminal this was causing the
      arrow keys to do something other than expected.

      There was a bug in the history list code which could result in
      strange entries appearing at the start of the history list once
      enough history lines had been added to the list to cause the
      circular history buffer to wrap. This is now fixed.

    Version 1.3.3:

      Signal handling has been re-written, and documentation of its
      behaviour has been added to the gl_get_line(3) man page. In addition
      to eliminating race conditions, and appropriately setting errno for
      those signals that abort gl_get_line(), many more signals are now
      intercepted, making it less likely that the terminal will be left in
      raw mode by a signal that isn't trapped by gl_get_line().

      A bug was also fixed that was leaving the terminal in raw mode if
      the editing mode was changed interactively between vi and emacs.
      This was only noticeable when running programs from old shells that
      don't reset terminal modes.

    Version 1.3.2:

      Tim Eliseo contributed a number of improvements to vi mode,
      including a fuller set of vi key-bindings, implementation of the vi
      constraint that the cursor can't backup past the point at which
      input mode was entered, and restoration of overwritten characters
      when backspacing in overwrite mode. There are also now new bindings
      to allow users to toggle between vi and emacs modes interactively.
      The terminal bell is now used in some circumstances, such as when an
      unrecognized key sequence is entered. This can be turned off by the
      new nobeep option in the tecla configuration file.

      Unrelated to the above, a problem under Linux which prevented ^Q
      from being used to resume terminal output after the user had pressed
      ^S, has been fixed.

    Version 1.3.1:

      In vi mode a bug was preventing the history-search-backward and
      history-search-forward actions from doing anything when invoked on
      empty lines. On empty lines they now act like up-history and
      down-history respectively, as in emacs mode.

      When creating shared libraries under Linux, the -soname directive
      was being used incorrectly. The result is that Linux binaries linked
      with the 1.2.3, 1.2.4 and 1.3.0 versions of the tecla shared
      libraries, will refuse to see other versions of the shared library
      until relinked with version 1.3.1 or higher.

      The configure script can now handle the fact that under Solaris-2.6
      and earlier, the only curses library is a static one that hides in
      /usr/ccs/lib. Under Linux it now also caters for old versions of GNU
      ld which don't accept version scripts.

      The demos are now linked against the shared version of the library
      if possible. Previously they were always linked with the static
      version.

    Version 1.3.0:

      The major change in this release is the addition of an optional vi
      command-line editing mode in gl_get_line(), along with lots of new
      action functions to support its bindings. To enable this, first
      create a ~/.teclarc file if you don't already have one, then add the
      following line to it.

       edit-mode vi

      The default vi bindings, which are designed to mimic those of the vi
      editor as closely as possible, are described in the gl_get_line(3)
      man page.

      A new convenience function called ef_list_expansions() has been
      added for listing filename expansions. See the ef_list_expansions(3)
      man page for details. This is used in a new list-glob binding, bound
      to ^Xg in emacs mode, and ^G in vi input mode.

      A bug has been fixed in the key-binding table expansion code. This
      bug would have caused problems to anybody who defined more than
      about 18 personalized key-bindings in their ~/.teclarc file.

    Version 1.2.4:

      Buffered I/O is now used for writing to terminals, and where
      supported, cursor motion is done with move-n-positions terminfo
      capabilities instead of doing lots of move-1-position requests. This
      greatly improves how the library feels over slow links.

      You can now optionally compile different architectures in different
      directories, without having to make multiple copies of the
      distribution. This is documented in the INSTALL file.

      The ksh ~+ directive is now supported.

      Thanks to Markus Gyger for the above improvements.

      Documentation has been added to the INSTALL file describing features
      designed to facilitate configuration and installation of the library
      as part of larger packages. These features are intended to remove
      the need to modify the tecla distribution's configuration and build
      procedures when embedding the libtecla distribution in other package
      distributions.

      A previous fix to stop the cursor from warping when the last
      character of the input line was in the last column of the terminal,
      was only being used for the first terminal line of the input line.
      It is now used for all subsequent lines as well, as originally
      intended.

    Version 1.2.3:

      The installation procedure has been better automated with the
      addition of an autoconf configure script. This means that installers
      can now compile and install the library by typing:

        ./configure
        make
        make install

      On all systems this makes at least the normal static version of the
      tecla library. It also makes the reentrant version if reentrant
      POSIX functions are detected.  Under Solaris, Linux and HP-UX the
      configuration script arranges for shared libraries to be compiled in
      addition to the static libraries.  It is hoped that installers will
      return information about how to compile shared libraries on other
      systems, for inclusion in future releases, and to this end, a new
      PORTING guide has been provided.

      The versioning number scheme has been changed. This release would
      have been 1.2c, but instead will be refered to as 1.2.3. The
      versioning scheme, based on conventions used by Sun Microsystems, is
      described in configure.in.

      The library was also tested under HP-UX, and this revealed two
      serious bugs, both of which have now been fixed.

      The first bug prevented the library from writing control codes to
      terminals on big-endian machines, with the exception of those
      running under Solaris. This was due to an int variable being used
      where a char was needed.

      The second bug had the symptom that on systems that don't use the
      newline character as the control code for moving the cursor down a
      line, a newline wasn't started when the user hit enter.

    Version 1.2b:

      Two more minor bug fixes:

      Many terminals don't wrap the cursor to the next line when a
      character is written to the rightmost terminal column. Instead, they
      delay starting a new line until one more character is written, at
      which point they move the cursor two positions.  gl_get_line()
      wasn't aware of this, so cursor repositionings just after writing
      the last character of a column, caused it to erroneously go up a
      line. This has now been remedied, using a method that should work
      regardless of whether a terminal exhibits this behavior or not.

      Some systems dynamically record the current terminal dimensions in
      environment variables called LINES and COLUMNS. On such systems,
      during the initial terminal setup, these values should override the
      static values read from the terminal information databases, and now
      do.  Previously they were only used if the dimensions returned by
      terminfo/termcap looked bogus.

    Version 1.2a:

      This minor release fixes the following two bugs:

      The initial terminal size and subsequent changes thereto, weren't
      being noticed by gl_get_line(). This was because the test for the
      existence of TIOCWINSZ was erroneously placed before the inclusion
      of termios.h. One of the results was that on input lines that
      spanned more than one terminal line, the cursor occasionally jumped
      unexpectedly to the previous terminal line.

      On entering a line that wrapped over multiple terminal lines,
      gl_get_line() simply output a carriage-return line-feed at the point
      at which the user pressed return. Thus if one typed in such a line,
      then moved back onto one of the earlier terminal lines before
      hitting return, the cursor was left on a line containing part of the
      line that had just been entered. This didn't do any harm, but it
      looked a mess.

    Version 1.2:

      A new facility for looking up and completing filenames in UNIX-style
      paths has now been added (eg. you can search for, or complete
      commands using the UNIX PATH environment variable). See the
      pca_lookup_file(3) man page.

      The already existing filename completion callback can now be made
      selective in what types of files it lists. See the
      cpl_complete_word(3) man page.

      Due to its potential to break applications when changed, the use of
      the publically defined CplFileArgs structure to configure the
      cpl_file_completions() callback is now deprecated.  The definition
      of this structure has been frozen, and its documentation has been
      removed from the man pages.  It will remain supported, but if you
      have used it, you are recommended to switch to the new method, which
      involves a new opaque configuration object, allocated via a provided
      constructor function, configured via accessor functions, and
      eventually deleted with a provided destructor function. The
      cpl_file_completions() callback distinguishes which structure type
      it has been sent by virtue of a code placed at the start of the new
      structure by the constructor.  It is assumed that no existing
      applications set the boolean 'escaped' member of the CplFileArgs
      structure to 4568.  The new method is documented in the
      cpl_complete_word(3) man page.

    Version 1.1j

      This was the initial public release on freshmeat.org.