libtecla(3) Library Functions Manual libtecla(3)

libtecla - An interactive command-line input library.

gcc ... -ltecla -lcurses

The tecla library provides programs with interactive command line editing facilities, similar to those of the unix tcsh shell. In addition to simple command-line editing, it supports recall of previously entered command lines, TAB completion of file names or other tokens, and in-line wild-card expansion of filenames. The internal functions which perform file-name completion and wild-card expansion are also available externally for optional use by the calling program.

The various parts of the library are documented in the following man pages:

  tecla(7)              -  Use level documentation of the
                        command-line editing facilities
                        provided by gl_get_line().
  gl_get_line(3)        -  The interactive line-input module.
  gl_io_mode(3)         -  How to use gl_get_line() in an
                        incremental, non-blocking fashion.
  cpl_complete_word(3)  -  The word completion module.
  ef_expand_file(3)     -  The filename expansion module.
  pca_lookup_file(3)    -  A directory-list based filename
                        lookup and completion module.

In addition there is one optional application distributed with the library:

  enhance(1)            -  Add command-line editing to third
                           party applications.

If the library is compiled with -D_POSIX_C_SOURCE=199506L, reentrant versions of as many functions as possible are used. This includes using getpwuid_r() and getpwnam_r() instead of getpwuid() and getpwnam() when looking up the home directories of specific users in the password file (for ~user/ expansion), and readdir_r() instead of readdir() for reading directory entries when doing filename completion. The reentrant version of the library is usually called libtecla_r.a instead of libtecla.a, so if only the latter is available, it probably isn't the correct version to link with threaded programs.

Reentrant functions for iterating through the password file aren't available, so when the library is compiled to be reentrant, TAB completion of incomplete usernames in ~username/ expressions is disabled. This doesn't disable expansion of complete ~username expressions, which can be done reentrantly, or expansion of the parts of filenames that follow them, so this doesn't remove much functionality.

The terminfo functions setupterm(), tigetstr(), tigetnum() and tputs() also aren't reentrant, but very few programs will want to interact with multiple terminals, so this shouldn't prevent this library from being used in threaded programs.

The version number of the library can be queried using the following function.

 void libtecla_version(int *major, int *minor, int *micro);

On return, this function records the three components of the libtecla version number in *major, *minor, *micro. The formal meaning of the three components is as follows.

 major - Incrementing this number implies that a change has
         been made to the library's public interface, which
         makes it binary incompatible  with programs that
         were linked with previous shared versions of the
         tecla library.
 minor - This number is incremented by one whenever
         additional functionality, such as new functions or
         modules, are added to the library.
 micro - This is incremented whenever modifications to the
         library are made which make no changes to the
         public interface, but which fix bugs and/or improve
         the behind-the-scenes implementation.

In Spanish, a "tecla" is the key of a keyboard. Since this library centers on keyboard input, and given that I wrote much of the library while working in Chile, this seemed like a suitable name.

libtecla.a    -   The tecla library.
libtecla.h    -   The tecla header file.
~/.teclarc    -   The tecla personal customization file.

gl_get_line(3), tecla(7), gl_io_mode(3), ef_expand_file(3),
cpl_complete_word(3), pca_lookup_file(3), enhance(1)

Martin Shepherd (

Markus Gyger  - Lots of assistance, including help with
                shared libraries, configuration information,
                particularly for Solaris; modifications to
                support C++ compilers, improvements for ksh
                users, faster cursor motion, output
                buffering, and changes to make gl_get_line()
                8-bit clean. 
Mike MacFaden - Suggestions, feedback and testing that led
                to many of the major new functions that were
                added in version 1.4.0.
Tim Eliseo    - Many vi-mode bindings and fixes.