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			1548 lines
		
	
	
	
		
			51 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
| @comment %**start of header (This is for running Texinfo on a region.)
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| @setfilename rltech.info
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| @comment %**end of header (This is for running Texinfo on a region.)
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| @setchapternewpage odd
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| 
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| @ifinfo
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| This document describes the GNU Readline Library, a utility for aiding
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| in the consitency of user interface across discrete programs that need
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| to provide a command line interface.
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| 
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| Copyright (C) 1988, 1994, 1996 Free Software Foundation, Inc.
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| 
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| Permission is granted to make and distribute verbatim copies of
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| this manual provided the copyright notice and this permission notice
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| pare preserved on all copies.
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| 
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| @ignore
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| Permission is granted to process this file through TeX and print the
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| results, provided the printed document carries copying permission
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| notice identical to this one except for the removal of this paragraph
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| (this paragraph not being relevant to the printed manual).
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| @end ignore
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| 
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| Permission is granted to copy and distribute modified versions of this
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| manual under the conditions for verbatim copying, provided that the entire
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| resulting derived work is distributed under the terms of a permission
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| notice identical to this one.
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| 
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| Permission is granted to copy and distribute translations of this manual
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| into another language, under the above conditions for modified versions,
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| except that this permission notice may be stated in a translation approved
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| by the Foundation.
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| @end ifinfo
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| 
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| @node Programming with GNU Readline
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| @chapter Programming with GNU Readline
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| 
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| This chapter describes the interface between the GNU Readline Library and
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| other programs.  If you are a programmer, and you wish to include the
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| features found in GNU Readline
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| such as completion, line editing, and interactive history manipulation
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| in your own programs, this section is for you.
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| 
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| @menu
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| * Basic Behavior::	Using the default behavior of Readline.
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| * Custom Functions::	Adding your own functions to Readline.
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| * Readline Variables::			Variables accessible to custom
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| 					functions.
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| * Readline Convenience Functions::	Functions which Readline supplies to
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| 					aid in writing your own
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| * Custom Completers::	Supplanting or supplementing Readline's
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| 			completion functions.
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| @end menu
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| 
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| @node Basic Behavior
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| @section Basic Behavior
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| 
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| Many programs provide a command line interface, such as @code{mail},
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| @code{ftp}, and @code{sh}.  For such programs, the default behaviour of
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| Readline is sufficient.  This section describes how to use Readline in
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| the simplest way possible, perhaps to replace calls in your code to
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| @code{gets()} or @code{fgets ()}.
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| 
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| @findex readline
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| @cindex readline, function
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| The function @code{readline ()} prints a prompt and then reads and returns
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| a single line of text from the user.  The line @code{readline}
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| returns is allocated with @code{malloc ()}; you should @code{free ()}
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| the line when you are done with it.  The declaration for @code{readline}
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| in ANSI C is
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| 
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| @example
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| @code{char *readline (char *@var{prompt});}
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| @end example
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| 
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| @noindent
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| So, one might say
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| @example
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| @code{char *line = readline ("Enter a line: ");}
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| @end example
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| @noindent
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| in order to read a line of text from the user.
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| The line returned has the final newline removed, so only the
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| text remains.
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| 
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| If @code{readline} encounters an @code{EOF} while reading the line, and the
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| line is empty at that point, then @code{(char *)NULL} is returned.
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| Otherwise, the line is ended just as if a newline had been typed.
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| 
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| If you want the user to be able to get at the line later, (with
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| @key{C-p} for example), you must call @code{add_history ()} to save the
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| line away in a @dfn{history} list of such lines.
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| 
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| @example
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| @code{add_history (line)};
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| @end example
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| 
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| @noindent
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| For full details on the GNU History Library, see the associated manual.
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| 
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| It is preferable to avoid saving empty lines on the history list, since
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| users rarely have a burning need to reuse a blank line.  Here is
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| a function which usefully replaces the standard @code{gets ()} library
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| function, and has the advantage of no static buffer to overflow:
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| 
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| @example
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| /* A static variable for holding the line. */
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| static char *line_read = (char *)NULL;
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| 
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| /* Read a string, and return a pointer to it.  Returns NULL on EOF. */
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| char *
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| rl_gets ()
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| @{
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|   /* If the buffer has already been allocated, return the memory
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|      to the free pool. */
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|   if (line_read)
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|     @{
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|       free (line_read);
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|       line_read = (char *)NULL;
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|     @}
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| 
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|   /* Get a line from the user. */
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|   line_read = readline ("");
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| 
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|   /* If the line has any text in it, save it on the history. */
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|   if (line_read && *line_read)
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|     add_history (line_read);
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| 
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|   return (line_read);
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| @}
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| @end example
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| 
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| This function gives the user the default behaviour of @key{TAB}
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| completion: completion on file names.  If you do not want Readline to
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| complete on filenames, you can change the binding of the @key{TAB} key
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| with @code{rl_bind_key ()}.
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| 
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| @example
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| @code{int rl_bind_key (int @var{key}, int (*@var{function})());}
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| @end example
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| 
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| @code{rl_bind_key ()} takes two arguments: @var{key} is the character that
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| you want to bind, and @var{function} is the address of the function to
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| call when @var{key} is pressed.  Binding @key{TAB} to @code{rl_insert ()}
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| makes @key{TAB} insert itself.
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| @code{rl_bind_key ()} returns non-zero if @var{key} is not a valid
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| ASCII character code (between 0 and 255).
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| 
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| Thus, to disable the default @key{TAB} behavior, the following suffices:
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| @example
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| @code{rl_bind_key ('\t', rl_insert);}
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| @end example
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| 
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| This code should be executed once at the start of your program; you
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| might write a function called @code{initialize_readline ()} which
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| performs this and other desired initializations, such as installing
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| custom completers (@pxref{Custom Completers}).
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| 
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| @node Custom Functions
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| @section Custom Functions
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| 
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| Readline provides many functions for manipulating the text of
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| the line, but it isn't possible to anticipate the needs of all
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| programs.  This section describes the various functions and variables
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| defined within the Readline library which allow a user program to add
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| customized functionality to Readline.
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| 
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| @menu
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| * The Function Type::	C declarations to make code readable.
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| * Function Writing::	Variables and calling conventions.
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| @end menu
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| 
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| @node The Function Type
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| @subsection The Function Type
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| 
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| For readabilty, we declare a new type of object, called
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| @dfn{Function}.  A @code{Function} is a C function which
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| returns an @code{int}.  The type declaration for @code{Function} is:
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| 
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| @noindent
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| @code{typedef int Function ();}
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| 
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| The reason for declaring this new type is to make it easier to write
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| code describing pointers to C functions.  Let us say we had a variable
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| called @var{func} which was a pointer to a function.  Instead of the
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| classic C declaration
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| 
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| @code{int (*)()func;}
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| 
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| @noindent
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| we may write
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| 
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| @code{Function *func;}
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| 
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| @noindent
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| Similarly, there are
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| 
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| @example
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| typedef void VFunction ();
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| typedef char *CPFunction (); @r{and}
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| typedef char **CPPFunction ();
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| @end example
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| 
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| @noindent
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| for functions returning no value, @code{pointer to char}, and
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| @code{pointer to pointer to char}, respectively.
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| 
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| @node Function Writing
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| @subsection Writing a New Function
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| 
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| In order to write new functions for Readline, you need to know the
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| calling conventions for keyboard-invoked functions, and the names of the
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| variables that describe the current state of the line read so far.
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| 
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| The calling sequence for a command @code{foo} looks like
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| 
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| @example
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| @code{foo (int count, int key)}
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| @end example
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| 
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| @noindent
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| where @var{count} is the numeric argument (or 1 if defaulted) and
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| @var{key} is the key that invoked this function.
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| 
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| It is completely up to the function as to what should be done with the
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| numeric argument.  Some functions use it as a repeat count, some
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| as a flag, and others to choose alternate behavior (refreshing the current
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| line as opposed to refreshing the screen, for example).  Some choose to
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| ignore it.  In general, if a
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| function uses the numeric argument as a repeat count, it should be able
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| to do something useful with both negative and positive arguments.
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| At the very least, it should be aware that it can be passed a
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| negative argument.
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| 
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| @node Readline Variables
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| @section Readline Variables
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| 
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| These variables are available to function writers.
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| 
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| @deftypevar {char *} rl_line_buffer
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| This is the line gathered so far.  You are welcome to modify the
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| contents of the line, but see @ref{Allowing Undoing}.
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| @end deftypevar
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| 
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| @deftypevar int rl_point
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| The offset of the current cursor position in @code{rl_line_buffer}
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| (the @emph{point}).
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| @end deftypevar
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| 
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| @deftypevar int rl_end
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| The number of characters present in @code{rl_line_buffer}.  When
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| @code{rl_point} is at the end of the line, @code{rl_point} and
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| @code{rl_end} are equal.
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| @end deftypevar
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| 
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| @deftypevar int rl_mark
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| The mark (saved position) in the current line.  If set, the mark
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| and point define a @emph{region}.
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| @end deftypevar
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| 
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| @deftypevar int rl_done
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| Setting this to a non-zero value causes Readline to return the current
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| line immediately.
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| @end deftypevar
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| 
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| @deftypevar int rl_pending_input
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| Setting this to a value makes it the next keystroke read.  This is a
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| way to stuff a single character into the input stream.
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| @end deftypevar
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| 
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| @deftypevar {char *} rl_prompt
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| The prompt Readline uses.  This is set from the argument to
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| @code{readline ()}, and should not be assigned to directly.
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| @end deftypevar
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| 
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| @deftypevar {char *} rl_library_version
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| The version number of this revision of the library.
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| @end deftypevar
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| 
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| @deftypevar {char *} rl_terminal_name
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| The terminal type, used for initialization.
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| @end deftypevar
 | |
| 
 | |
| @deftypevar {char *} rl_readline_name
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| This variable is set to a unique name by each application using Readline.
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| The value allows conditional parsing of the inputrc file
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| (@pxref{Conditional Init Constructs}).
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| @end deftypevar
 | |
| 
 | |
| @deftypevar {FILE *} rl_instream
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| The stdio stream from which Readline reads input.
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| @end deftypevar
 | |
| 
 | |
| @deftypevar {FILE *} rl_outstream
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| The stdio stream to which Readline performs output.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {Function *} rl_startup_hook
 | |
| If non-zero, this is the address of a function to call just
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| before @code{readline} prints the first prompt.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {Function *} rl_event_hook
 | |
| If non-zero, this is the address of a function to call periodically
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| when readline is waiting for terminal input.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {Function *} rl_getc_function
 | |
| If non-zero, @code{readline} will call indirectly through this pointer
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| to get a character from the input stream.  By default, it is set to
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| @code{rl_getc}, the default @code{readline} character input function
 | |
| (@pxref{Utility Functions}).
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {VFunction *} rl_redisplay_function
 | |
| If non-zero, @code{readline} will call indirectly through this pointer
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| to update the display with the current contents of the editing buffer.
 | |
| By default, it is set to @code{rl_redisplay}, the default @code{readline}
 | |
| redisplay function (@pxref{Redisplay}).
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {Keymap} rl_executing_keymap
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| This variable is set to the keymap (@pxref{Keymaps}) in which the
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| currently executing readline function was found.
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| @end deftypevar 
 | |
| 
 | |
| @deftypevar {Keymap} rl_binding_keymap
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| This variable is set to the keymap (@pxref{Keymaps}) in which the
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| last key binding occurred.
 | |
| @end deftypevar 
 | |
| 
 | |
| @node Readline Convenience Functions
 | |
| @section Readline Convenience Functions
 | |
| 
 | |
| @menu
 | |
| * Function Naming::	How to give a function you write a name.
 | |
| * Keymaps::		Making keymaps.
 | |
| * Binding Keys::	Changing Keymaps.
 | |
| * Associating Function Names and Bindings::	Translate function names to
 | |
| 						key sequences.
 | |
| * Allowing Undoing::	How to make your functions undoable.
 | |
| * Redisplay::		Functions to control line display.
 | |
| * Modifying Text::	Functions to modify @code{rl_line_buffer}.
 | |
| * Utility Functions::	Generally useful functions and hooks.
 | |
| * Alternate Interface::	Using Readline in a `callback' fashion.
 | |
| @end menu
 | |
| 
 | |
| @node Function Naming
 | |
| @subsection Naming a Function
 | |
| 
 | |
| The user can dynamically change the bindings of keys while using
 | |
| Readline.  This is done by representing the function with a descriptive
 | |
| name.  The user is able to type the descriptive name when referring to
 | |
| the function.  Thus, in an init file, one might find
 | |
| 
 | |
| @example
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| Meta-Rubout:	backward-kill-word
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| @end example
 | |
| 
 | |
| This binds the keystroke @key{Meta-Rubout} to the function
 | |
| @emph{descriptively} named @code{backward-kill-word}.  You, as the
 | |
| programmer, should bind the functions you write to descriptive names as
 | |
| well.  Readline provides a function for doing that:
 | |
| 
 | |
| @deftypefun int rl_add_defun (char *name, Function *function, int key)
 | |
| Add @var{name} to the list of named functions.  Make @var{function} be
 | |
| the function that gets called.  If @var{key} is not -1, then bind it to
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| @var{function} using @code{rl_bind_key ()}.
 | |
| @end deftypefun
 | |
| 
 | |
| Using this function alone is sufficient for most applications.  It is
 | |
| the recommended way to add a few functions to the default functions that
 | |
| Readline has built in.  If you need to do something other
 | |
| than adding a function to Readline, you may need to use the
 | |
| underlying functions described below.
 | |
| 
 | |
| @node Keymaps
 | |
| @subsection Selecting a Keymap
 | |
| 
 | |
| Key bindings take place on a @dfn{keymap}.  The keymap is the
 | |
| association between the keys that the user types and the functions that
 | |
| get run.  You can make your own keymaps, copy existing keymaps, and tell
 | |
| Readline which keymap to use.
 | |
| 
 | |
| @deftypefun Keymap rl_make_bare_keymap ()
 | |
| Returns a new, empty keymap.  The space for the keymap is allocated with
 | |
| @code{malloc ()}; you should @code{free ()} it when you are done.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun Keymap rl_copy_keymap (Keymap map)
 | |
| Return a new keymap which is a copy of @var{map}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun Keymap rl_make_keymap ()
 | |
| Return a new keymap with the printing characters bound to rl_insert,
 | |
| the lowercase Meta characters bound to run their equivalents, and
 | |
| the Meta digits bound to produce numeric arguments.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun void rl_discard_keymap (Keymap keymap)
 | |
| Free the storage associated with @var{keymap}.
 | |
| @end deftypefun
 | |
| 
 | |
| Readline has several internal keymaps.  These functions allow you to
 | |
| change which keymap is active.
 | |
| 
 | |
| @deftypefun Keymap rl_get_keymap ()
 | |
| Returns the currently active keymap.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun void rl_set_keymap (Keymap keymap)
 | |
| Makes @var{keymap} the currently active keymap.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun Keymap rl_get_keymap_by_name (char *name)
 | |
| Return the keymap matching @var{name}.  @var{name} is one which would
 | |
| be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}).
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun {char *} rl_get_keymap_name (Keymap keymap)
 | |
| Return the name matching @var{keymap}.  @var{name} is one which would
 | |
| be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}).
 | |
| @end deftypefun
 | |
| 
 | |
| @node Binding Keys
 | |
| @subsection Binding Keys
 | |
| 
 | |
| You associate keys with functions through the keymap.  Readline has
 | |
| several internal keymaps: @code{emacs_standard_keymap},
 | |
| @code{emacs_meta_keymap}, @code{emacs_ctlx_keymap},
 | |
| @code{vi_movement_keymap}, and @code{vi_insertion_keymap}.
 | |
| @code{emacs_standard_keymap} is the default, and the examples in
 | |
| this manual assume that.
 | |
| 
 | |
| These functions manage key bindings.
 | |
| 
 | |
| @deftypefun int rl_bind_key (int key, Function *function)
 | |
| Binds @var{key} to @var{function} in the currently active keymap.
 | |
| Returns non-zero in the case of an invalid @var{key}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_bind_key_in_map (int key, Function *function, Keymap map)
 | |
| Bind @var{key} to @var{function} in @var{map}.  Returns non-zero in the case
 | |
| of an invalid @var{key}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_unbind_key (int key)
 | |
| Bind @var{key} to the null function in the currently active keymap.
 | |
| Returns non-zero in case of error.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_unbind_key_in_map (int key, Keymap map)
 | |
| Bind @var{key} to the null function in @var{map}.
 | |
| Returns non-zero in case of error.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_unbind_function_in_map (Function *function, Keymap map)
 | |
| Unbind all keys that execute @var{function} in @var{map}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_unbind_command_in_map (char *command, Keymap map)
 | |
| Unbind all keys that are bound to @var{command} in @var{map}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_generic_bind (int type, char *keyseq, char *data, Keymap map)
 | |
| Bind the key sequence represented by the string @var{keyseq} to the arbitrary
 | |
| pointer @var{data}.  @var{type} says what kind of data is pointed to by
 | |
| @var{data}; this can be a function (@code{ISFUNC}), a macro
 | |
| (@code{ISMACR}), or a keymap (@code{ISKMAP}).  This makes new keymaps as
 | |
| necessary.  The initial keymap in which to do bindings is @var{map}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_parse_and_bind (char *line)
 | |
| Parse @var{line} as if it had been read from the @code{inputrc} file and
 | |
| perform any key bindings and variable assignments found
 | |
| (@pxref{Readline Init File}).
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_read_init_file (char *filename)
 | |
| Read keybindings and variable assignments from @var{filename}
 | |
| (@pxref{Readline Init File}).
 | |
| @end deftypefun
 | |
| 
 | |
| @node Associating Function Names and Bindings
 | |
| @subsection Associating Function Names and Bindings
 | |
| 
 | |
| These functions allow you to find out what keys invoke named functions
 | |
| and the functions invoked by a particular key sequence.
 | |
| 
 | |
| @deftypefun {Function *} rl_named_function (char *name)
 | |
| Return the function with name @var{name}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun {Function *} rl_function_of_keyseq (char *keyseq, Keymap map, int *type)
 | |
| Return the function invoked by @var{keyseq} in keymap @var{map}.
 | |
| If @var{map} is NULL, the current keymap is used.  If @var{type} is
 | |
| not NULL, the type of the object is returned in it (one of @code{ISFUNC},
 | |
| @code{ISKMAP}, or @code{ISMACR}).
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun {char **} rl_invoking_keyseqs (Function *function)
 | |
| Return an array of strings representing the key sequences used to
 | |
| invoke @var{function} in the current keymap.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun {char **} rl_invoking_keyseqs_in_map (Function *function, Keymap map)
 | |
| Return an array of strings representing the key sequences used to
 | |
| invoke @var{function} in the keymap @var{map}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun void rl_function_dumper (int readable)
 | |
| Print the readline function names and the key sequences currently
 | |
| bound to them to @code{rl_outstream}.  If @var{readable} is non-zero,
 | |
| the list is formatted in such a way that it can be made part of an
 | |
| @code{inputrc} file and re-read.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun void rl_list_funmap_names ()
 | |
| Print the names of all bindable Readline functions to @code{rl_outstream}.
 | |
| @end deftypefun
 | |
| 
 | |
| @node Allowing Undoing
 | |
| @subsection Allowing Undoing
 | |
| 
 | |
| Supporting the undo command is a painless thing, and makes your
 | |
| functions much more useful.  It is certainly easy to try
 | |
| something if you know you can undo it.  I could use an undo function for
 | |
| the stock market.
 | |
| 
 | |
| If your function simply inserts text once, or deletes text once, and
 | |
| uses @code{rl_insert_text ()} or @code{rl_delete_text ()} to do it, then
 | |
| undoing is already done for you automatically.
 | |
| 
 | |
| If you do multiple insertions or multiple deletions, or any combination
 | |
| of these operations, you should group them together into one operation.
 | |
| This is done with @code{rl_begin_undo_group ()} and
 | |
| @code{rl_end_undo_group ()}.
 | |
| 
 | |
| The types of events that can be undone are:
 | |
| 
 | |
| @example
 | |
| enum undo_code @{ UNDO_DELETE, UNDO_INSERT, UNDO_BEGIN, UNDO_END @}; 
 | |
| @end example
 | |
| 
 | |
| Notice that @code{UNDO_DELETE} means to insert some text, and
 | |
| @code{UNDO_INSERT} means to delete some text.  That is, the undo code
 | |
| tells undo what to undo, not how to undo it.  @code{UNDO_BEGIN} and
 | |
| @code{UNDO_END} are tags added by @code{rl_begin_undo_group ()} and
 | |
| @code{rl_end_undo_group ()}.
 | |
| 
 | |
| @deftypefun int rl_begin_undo_group ()
 | |
| Begins saving undo information in a group construct.  The undo
 | |
| information usually comes from calls to @code{rl_insert_text ()} and
 | |
| @code{rl_delete_text ()}, but could be the result of calls to
 | |
| @code{rl_add_undo ()}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_end_undo_group ()
 | |
| Closes the current undo group started with @code{rl_begin_undo_group
 | |
| ()}.  There should be one call to @code{rl_end_undo_group ()}
 | |
| for each call to @code{rl_begin_undo_group ()}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun void rl_add_undo (enum undo_code what, int start, int end, char *text)
 | |
| Remember how to undo an event (according to @var{what}).  The affected
 | |
| text runs from @var{start} to @var{end}, and encompasses @var{text}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun void free_undo_list ()
 | |
| Free the existing undo list.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_do_undo ()
 | |
| Undo the first thing on the undo list.  Returns @code{0} if there was
 | |
| nothing to undo, non-zero if something was undone.
 | |
| @end deftypefun
 | |
| 
 | |
| Finally, if you neither insert nor delete text, but directly modify the
 | |
| existing text (e.g., change its case), call @code{rl_modifying ()}
 | |
| once, just before you modify the text.  You must supply the indices of
 | |
| the text range that you are going to modify.
 | |
| 
 | |
| @deftypefun int rl_modifying (int start, int end)
 | |
| Tell Readline to save the text between @var{start} and @var{end} as a
 | |
| single undo unit.  It is assumed that you will subsequently modify
 | |
| that text.
 | |
| @end deftypefun
 | |
| 
 | |
| @node Redisplay
 | |
| @subsection Redisplay
 | |
| 
 | |
| @deftypefun void rl_redisplay ()
 | |
| Change what's displayed on the screen to reflect the current contents
 | |
| of @code{rl_line_buffer}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_forced_update_display ()
 | |
| Force the line to be updated and redisplayed, whether or not
 | |
| Readline thinks the screen display is correct.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_on_new_line ()
 | |
| Tell the update routines that we have moved onto a new (empty) line,
 | |
| usually after ouputting a newline.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_reset_line_state ()
 | |
| Reset the display state to a clean state and redisplay the current line
 | |
| starting on a new line.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_message (va_alist)
 | |
| The arguments are a string as would be supplied to @code{printf}.  The
 | |
| resulting string is displayed in the @dfn{echo area}.  The echo area
 | |
| is also used to display numeric arguments and search strings.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_clear_message ()
 | |
| Clear the message in the echo area.
 | |
| @end deftypefun
 | |
| 
 | |
| @node Modifying Text
 | |
| @subsection Modifying Text
 | |
| 
 | |
| @deftypefun int rl_insert_text (char *text)
 | |
| Insert @var{text} into the line at the current cursor position.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_delete_text (int start, int end)
 | |
| Delete the text between @var{start} and @var{end} in the current line.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun {char *} rl_copy_text (int start, int end)
 | |
| Return a copy of the text between @var{start} and @var{end} in
 | |
| the current line.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_kill_text (int start, int end)
 | |
| Copy the text between @var{start} and @var{end} in the current line
 | |
| to the kill ring, appending or prepending to the last kill if the
 | |
| last command was a kill command.  The text is deleted.
 | |
| If @var{start} is less than @var{end},
 | |
| the text is appended, otherwise prepended.  If the last command was
 | |
| not a kill, a new kill ring slot is used.
 | |
| @end deftypefun
 | |
| 
 | |
| @node Utility Functions
 | |
| @subsection Utility Functions
 | |
| 
 | |
| @deftypefun int rl_read_key ()
 | |
| Return the next character available.  This handles input inserted into
 | |
| the input stream via @var{pending input} (@pxref{Readline Variables})
 | |
| and @code{rl_stuff_char ()}, macros, and characters read from the keyboard.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_getc (FILE *)
 | |
| Return the next character available from the keyboard.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_stuff_char (int c)
 | |
| Insert @var{c} into the Readline input stream.  It will be "read"
 | |
| before Readline attempts to read characters from the terminal with
 | |
| @code{rl_read_key ()}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun rl_extend_line_buffer (int len)
 | |
| Ensure that @code{rl_line_buffer} has enough space to hold @var{len}
 | |
| characters, possibly reallocating it if necessary.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_initialize ()
 | |
| Initialize or re-initialize Readline's internal state.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_reset_terminal (char *terminal_name)
 | |
| Reinitialize Readline's idea of the terminal settings using
 | |
| @var{terminal_name} as the terminal type (e.g., @code{vt100}).
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int alphabetic (int c)
 | |
| Return 1 if @var{c} is an alphabetic character.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int numeric (int c)
 | |
| Return 1 if @var{c} is a numeric character.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int ding ()
 | |
| Ring the terminal bell, obeying the setting of @code{bell-style}.
 | |
| @end deftypefun
 | |
| 
 | |
| The following are implemented as macros, defined in @code{chartypes.h}.
 | |
| 
 | |
| @deftypefun int uppercase_p (int c)
 | |
| Return 1 if @var{c} is an uppercase alphabetic character.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int lowercase_p (int c)
 | |
| Return 1 if @var{c} is a lowercase alphabetic character.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int digit_p (int c)
 | |
| Return 1 if @var{c} is a numeric character.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int to_upper (int c)
 | |
| If @var{c} is a lowercase alphabetic character, return the corresponding
 | |
| uppercase character.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int to_lower (int c)
 | |
| If @var{c} is an uppercase alphabetic character, return the corresponding
 | |
| lowercase character.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int digit_value (int c)
 | |
| If @var{c} is a number, return the value it represents.
 | |
| @end deftypefun
 | |
| 
 | |
| @node Alternate Interface
 | |
| @subsection Alternate Interface
 | |
| 
 | |
| An alternate interface is available to plain @code{readline()}.  Some
 | |
| applications need to interleave keyboard I/O with file, device, or
 | |
| window system I/O, typically by using a main loop to @code{select()}
 | |
| on various file descriptors.  To accomodate this need, readline can
 | |
| also be invoked as a `callback' function from an event loop.  There
 | |
| are functions available to make this easy.
 | |
| 
 | |
| @deftypefun void rl_callback_handler_install (char *prompt, Vfunction *lhandler)
 | |
| Set up the terminal for readline I/O and display the initial
 | |
| expanded value of @var{prompt}.  Save the value of @var{lhandler} to
 | |
| use as a callback when a complete line of input has been entered.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun void rl_callback_read_char ()
 | |
| Whenever an application determines that keyboard input is available, it
 | |
| should call @code{rl_callback_read_char()}, which will read the next
 | |
| character from the current input source.  If that character completes the
 | |
| line, @code{rl_callback_read_char} will invoke the @var{lhandler}
 | |
| function saved by @code{rl_callback_handler_install} to process the
 | |
| line.  @code{EOF} is  indicated by calling @var{lhandler} with a
 | |
| @code{NULL} line.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun void rl_callback_handler_remove ()
 | |
| Restore the terminal to its initial state and remove the line handler.
 | |
| This may be called from within a callback as well as independently.
 | |
| @end deftypefun
 | |
| 
 | |
| @subsection An Example
 | |
| 
 | |
| Here is a function which changes lowercase characters to their uppercase
 | |
| equivalents, and uppercase characters to lowercase.  If
 | |
| this function was bound to @samp{M-c}, then typing @samp{M-c} would
 | |
| change the case of the character under point.  Typing @samp{M-1 0 M-c}
 | |
| would change the case of the following 10 characters, leaving the cursor on
 | |
| the last character changed.
 | |
| 
 | |
| @example
 | |
| /* Invert the case of the COUNT following characters. */
 | |
| int
 | |
| invert_case_line (count, key)
 | |
|      int count, key;
 | |
| @{
 | |
|   register int start, end, i;
 | |
| 
 | |
|   start = rl_point;
 | |
| 
 | |
|   if (rl_point >= rl_end)
 | |
|     return (0);
 | |
| 
 | |
|   if (count < 0)
 | |
|     @{
 | |
|       direction = -1;
 | |
|       count = -count;
 | |
|     @}
 | |
|   else
 | |
|     direction = 1;
 | |
|       
 | |
|   /* Find the end of the range to modify. */
 | |
|   end = start + (count * direction);
 | |
| 
 | |
|   /* Force it to be within range. */
 | |
|   if (end > rl_end)
 | |
|     end = rl_end;
 | |
|   else if (end < 0)
 | |
|     end = 0;
 | |
| 
 | |
|   if (start == end)
 | |
|     return (0);
 | |
| 
 | |
|   if (start > end)
 | |
|     @{
 | |
|       int temp = start;
 | |
|       start = end;
 | |
|       end = temp;
 | |
|     @}
 | |
| 
 | |
|   /* Tell readline that we are modifying the line, so it will save
 | |
|      the undo information. */
 | |
|   rl_modifying (start, end);
 | |
| 
 | |
|   for (i = start; i != end; i++)
 | |
|     @{
 | |
|       if (uppercase_p (rl_line_buffer[i]))
 | |
|         rl_line_buffer[i] = to_lower (rl_line_buffer[i]);
 | |
|       else if (lowercase_p (rl_line_buffer[i]))
 | |
|         rl_line_buffer[i] = to_upper (rl_line_buffer[i]);
 | |
|     @}
 | |
|   /* Move point to on top of the last character changed. */
 | |
|   rl_point = (direction == 1) ? end - 1 : start;
 | |
|   return (0);
 | |
| @}
 | |
| @end example
 | |
| 
 | |
| @node Custom Completers
 | |
| @section Custom Completers
 | |
| 
 | |
| Typically, a program that reads commands from the user has a way of
 | |
| disambiguating commands and data.  If your program is one of these, then
 | |
| it can provide completion for commands, data, or both.
 | |
| The following sections describe how your program and Readline
 | |
| cooperate to provide this service.
 | |
| 
 | |
| @menu
 | |
| * How Completing Works::	The logic used to do completion.
 | |
| * Completion Functions::	Functions provided by Readline.
 | |
| * Completion Variables::	Variables which control completion.
 | |
| * A Short Completion Example::	An example of writing completer subroutines.
 | |
| @end menu
 | |
| 
 | |
| @node How Completing Works
 | |
| @subsection How Completing Works
 | |
| 
 | |
| In order to complete some text, the full list of possible completions
 | |
| must be available.  That is, it is not possible to accurately
 | |
| expand a partial word without knowing all of the possible words
 | |
| which make sense in that context.  The Readline library provides
 | |
| the user interface to completion, and two of the most common
 | |
| completion functions:  filename and username.  For completing other types
 | |
| of text, you must write your own completion function.  This section
 | |
| describes exactly what such functions must do, and provides an example.
 | |
| 
 | |
| There are three major functions used to perform completion:
 | |
| 
 | |
| @enumerate
 | |
| @item
 | |
| The user-interface function @code{rl_complete ()}.  This function is
 | |
| called with the same arguments as other Readline
 | |
| functions intended for interactive use:  @var{count} and
 | |
| @var{invoking_key}.  It isolates the word to be completed and calls
 | |
| @code{completion_matches ()} to generate a list of possible completions.
 | |
| It then either lists the possible completions, inserts the possible
 | |
| completions, or actually performs the
 | |
| completion, depending on which behavior is desired.
 | |
| 
 | |
| @item
 | |
| The internal function @code{completion_matches ()} uses your
 | |
| @dfn{generator} function to generate the list of possible matches, and
 | |
| then returns the array of these matches.  You should place the address
 | |
| of your generator function in @code{rl_completion_entry_function}.
 | |
| 
 | |
| @item
 | |
| The generator function is called repeatedly from
 | |
| @code{completion_matches ()}, returning a string each time.  The
 | |
| arguments to the generator function are @var{text} and @var{state}.
 | |
| @var{text} is the partial word to be completed.  @var{state} is zero the
 | |
| first time the function is called, allowing the generator to perform
 | |
| any necessary initialization, and a positive non-zero integer for
 | |
| each subsequent call.  When the generator function returns
 | |
| @code{(char *)NULL} this signals @code{completion_matches ()} that there are
 | |
| no more possibilities left.  Usually the generator function computes the
 | |
| list of possible completions when @var{state} is zero, and returns them
 | |
| one at a time on subsequent calls.  Each string the generator function
 | |
| returns as a match must be allocated with @code{malloc()}; Readline
 | |
| frees the strings when it has finished with them.
 | |
| 
 | |
| @end enumerate
 | |
| 
 | |
| @deftypefun int rl_complete (int ignore, int invoking_key)
 | |
| Complete the word at or before point.  You have supplied the function
 | |
| that does the initial simple matching selection algorithm (see
 | |
| @code{completion_matches ()}).  The default is to do filename completion.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypevar {Function *} rl_completion_entry_function
 | |
| This is a pointer to the generator function for @code{completion_matches
 | |
| ()}.  If the value of @code{rl_completion_entry_function} is
 | |
| @code{(Function *)NULL} then the default filename generator function,
 | |
| @code{filename_completion_function ()}, is used.
 | |
| @end deftypevar
 | |
| 
 | |
| @node Completion Functions
 | |
| @subsection Completion Functions
 | |
| 
 | |
| Here is the complete list of callable completion functions present in
 | |
| Readline.
 | |
| 
 | |
| @deftypefun int rl_complete_internal (int what_to_do)
 | |
| Complete the word at or before point.  @var{what_to_do} says what to do
 | |
| with the completion.  A value of @samp{?} means list the possible
 | |
| completions.  @samp{TAB} means do standard completion.  @samp{*} means
 | |
| insert all of the possible completions.  @samp{!} means to display
 | |
| all of the possible completions, if there is more than one, as well as
 | |
| performing partial completion.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_complete (int ignore, int invoking_key)
 | |
| Complete the word at or before point.  You have supplied the function
 | |
| that does the initial simple matching selection algorithm (see
 | |
| @code{completion_matches ()} and @code{rl_completion_entry_function}).
 | |
| The default is to do filename
 | |
| completion.  This calls @code{rl_complete_internal ()} with an
 | |
| argument depending on @var{invoking_key}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_possible_completions (int count, int invoking_key))
 | |
| List the possible completions.  See description of @code{rl_complete
 | |
| ()}.  This calls @code{rl_complete_internal ()} with an argument of
 | |
| @samp{?}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun int rl_insert_completions (int count, int invoking_key))
 | |
| Insert the list of possible completions into the line, deleting the
 | |
| partially-completed word.  See description of @code{rl_complete ()}.
 | |
| This calls @code{rl_complete_internal ()} with an argument of @samp{*}.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun {char **} completion_matches (char *text, CPFunction *entry_func)
 | |
| Returns an array of @code{(char *)} which is a list of completions for
 | |
| @var{text}.  If there are no completions, returns @code{(char **)NULL}.
 | |
| The first entry in the returned array is the substitution for @var{text}.
 | |
| The remaining entries are the possible completions.  The array is
 | |
| terminated with a @code{NULL} pointer.
 | |
| 
 | |
| @var{entry_func} is a function of two args, and returns a
 | |
| @code{(char *)}.  The first argument is @var{text}.  The second is a
 | |
| state argument; it is zero on the first call, and non-zero on subsequent
 | |
| calls.  @var{entry_func} returns a @code{NULL}  pointer to the caller
 | |
| when there are no more matches.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun {char *} filename_completion_function (char *text, int state)
 | |
| A generator function for filename completion in the general case.  Note
 | |
| that completion in Bash is a little different because of all
 | |
| the pathnames that must be followed when looking up completions for a
 | |
| command.  The Bash source is a useful reference for writing custom
 | |
| completion functions.
 | |
| @end deftypefun
 | |
| 
 | |
| @deftypefun {char *} username_completion_function (char *text, int state)
 | |
| A completion generator for usernames.  @var{text} contains a partial
 | |
| username preceded by a random character (usually @samp{~}).  As with all
 | |
| completion generators, @var{state} is zero on the first call and non-zero
 | |
| for subsequent calls.
 | |
| @end deftypefun
 | |
| 
 | |
| @node Completion Variables
 | |
| @subsection Completion Variables
 | |
| 
 | |
| @deftypevar {Function *} rl_completion_entry_function
 | |
| A pointer to the generator function for @code{completion_matches ()}.
 | |
| @code{NULL} means to use @code{filename_entry_function ()}, the default
 | |
| filename completer.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {CPPFunction *} rl_attempted_completion_function
 | |
| A pointer to an alternative function to create matches.
 | |
| The function is called with @var{text}, @var{start}, and @var{end}.
 | |
| @var{start} and @var{end} are indices in @code{rl_line_buffer} saying
 | |
| what the boundaries of @var{text} are.  If this function exists and
 | |
| returns @code{NULL}, or if this variable is set to @code{NULL}, then
 | |
| @code{rl_complete ()} will call the value of
 | |
| @code{rl_completion_entry_function} to generate matches, otherwise the
 | |
| array of strings returned will be used.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {CPFunction *} rl_filename_quoting_function
 | |
| A pointer to a function that will quote a filename in an application-
 | |
| specific fashion.  This is called if filename completion is being
 | |
| attempted and one of the characters in @code{rl_filename_quote_characters}
 | |
| appears in a completed filename.  The function is called with
 | |
| @var{text}, @var{match_type}, and @var{quote_pointer}.  The @var{text}
 | |
| is the filename to be quoted.  The @var{match_type} is either
 | |
| @code{SINGLE_MATCH}, if there is only one completion match, or
 | |
| @code{MULT_MATCH}.  Some functions use this to decide whether or not to
 | |
| insert a closing quote character.  The @var{quote_pointer} is a pointer
 | |
| to any opening quote character the user typed.  Some functions choose
 | |
| to reset this character.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {CPFunction *} rl_filename_dequoting_function
 | |
| A pointer to a function that will remove application-specific quoting
 | |
| characters from a filename before completion is attempted, so those
 | |
| characters do not interfere with matching the text against names in
 | |
| the filesystem.  It is called with @var{text}, the text of the word
 | |
| to be dequoted, and @var{quote_char}, which is the quoting character 
 | |
| that delimits the filename (usually @samp{'} or @samp{"}).  If
 | |
| @var{quote_char} is zero, the filename was not in an embedded string.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {Function *} rl_char_is_quoted_p
 | |
| A pointer to a function to call that determines whether or not a specific
 | |
| character in the line buffer is quoted, according to whatever quoting
 | |
| mechanism the program calling readline uses.  The function is called with
 | |
| two arguments: @var{text}, the text of the line, and @var{index}, the
 | |
| index of the character in the line.  It is used to decide whether a
 | |
| character found in @code{rl_completer_word_break_characters} should be
 | |
| used to break words for the completer.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar int rl_completion_query_items
 | |
| Up to this many items will be displayed in response to a
 | |
| possible-completions call.  After that, we ask the user if she is sure
 | |
| she wants to see them all.  The default value is 100.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {char *} rl_basic_word_break_characters
 | |
| The basic list of characters that signal a break between words for the
 | |
| completer routine.  The default value of this variable is the characters
 | |
| which break words for completion in Bash, i.e.,
 | |
| @code{" \t\n\"\\'`@@$><=;|&@{("}.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {char *} rl_basic_quote_characters
 | |
| List of quote characters which can cause a word break.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {char *} rl_completer_word_break_characters
 | |
| The list of characters that signal a break between words for
 | |
| @code{rl_complete_internal ()}.  The default list is the value of
 | |
| @code{rl_basic_word_break_characters}.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {char *} rl_completer_quote_characters
 | |
| List of characters which can be used to quote a substring of the line.
 | |
| Completion occurs on the entire substring, and within the substring
 | |
| @code{rl_completer_word_break_characters} are treated as any other character,
 | |
| unless they also appear within this list.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {char *} rl_filename_quote_characters
 | |
| A list of characters that cause a filename to be quoted by the completer
 | |
| when they appear in a completed filename.  The default is the null string.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {char *} rl_special_prefixes
 | |
| The list of characters that are word break characters, but should be
 | |
| left in @var{text} when it is passed to the completion function.
 | |
| Programs can use this to help determine what kind of completing to do.
 | |
| For instance, Bash sets this variable to "$@@" so that it can complete
 | |
| shell variables and hostnames.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {int} rl_completion_append_character
 | |
| When a single completion alternative matches at the end of the command
 | |
| line, this character is appended to the inserted completion text.  The
 | |
| default is a space character (@samp{ }).  Setting this to the null
 | |
| character (@samp{\0}) prevents anything being appended automatically.
 | |
| This can be changed in custom completion functions to
 | |
| provide the ``most sensible word separator character'' according to
 | |
| an application-specific command line syntax specification.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar int rl_ignore_completion_duplicates
 | |
| If non-zero, then disallow duplicates in the matches.  Default is 1.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar int rl_filename_completion_desired
 | |
| Non-zero means that the results of the matches are to be treated as
 | |
| filenames.  This is @emph{always} zero on entry, and can only be changed
 | |
| within a completion entry generator function.  If it is set to a non-zero
 | |
| value, directory names have a slash appended and Readline attempts to
 | |
| quote completed filenames if they contain any embedded word break
 | |
| characters.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar int rl_filename_quoting_desired
 | |
| Non-zero means that the results of the matches are to be quoted using
 | |
| double quotes (or an application-specific quoting mechanism) if the
 | |
| completed filename contains any characters in
 | |
| @code{rl_filename_quote_chars}.  This is @emph{always} non-zero
 | |
| on entry, and can only be changed within a completion entry generator
 | |
| function.  The quoting is effected via a call to the function pointed to
 | |
| by @code{rl_filename_quoting_function}.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar int rl_inhibit_completion
 | |
| If this variable is non-zero, completion is inhibit<ed.  The completion
 | |
| character will be inserted as any other bound to @code{self-insert}.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {Function *} rl_ignore_some_completions_function
 | |
| This function, if defined, is called by the completer when real filename
 | |
| completion is done, after all the matching names have been generated.
 | |
| It is passed a @code{NULL} terminated array of matches.
 | |
| The first element (@code{matches[0]}) is the
 | |
| maximal substring common to all matches. This function can
 | |
| re-arrange the list of matches as required, but each element deleted
 | |
| from the array must be freed.
 | |
| @end deftypevar
 | |
| 
 | |
| @deftypevar {Function *} rl_directory_completion_hook
 | |
| This function, if defined, is allowed to modify the directory portion
 | |
| of filenames Readline completes.  It is called with the address of a
 | |
| string (the current directory name) as an argument.  It could be used
 | |
| to expand symbolic links or shell variables in pathnames.
 | |
| @end deftypevar
 | |
| 
 | |
| @node A Short Completion Example
 | |
| @subsection A Short Completion Example
 | |
| 
 | |
| Here is a small application demonstrating the use of the GNU Readline
 | |
| library.  It is called @code{fileman}, and the source code resides in
 | |
| @file{examples/fileman.c}.  This sample application provides
 | |
| completion of command names, line editing features, and access to the
 | |
| history list.
 | |
| 
 | |
| @page
 | |
| @smallexample
 | |
| /* fileman.c -- A tiny application which demonstrates how to use the
 | |
|    GNU Readline library.  This application interactively allows users
 | |
|    to manipulate files and their modes. */
 | |
| 
 | |
| #include <stdio.h>
 | |
| #include <sys/types.h>
 | |
| #include <sys/file.h>
 | |
| #include <sys/stat.h>
 | |
| #include <sys/errno.h>
 | |
| 
 | |
| #include <readline/readline.h>
 | |
| #include <readline/history.h>
 | |
| 
 | |
| extern char *getwd ();
 | |
| extern char *xmalloc ();
 | |
| 
 | |
| /* The names of functions that actually do the manipulation. */
 | |
| int com_list (), com_view (), com_rename (), com_stat (), com_pwd ();
 | |
| int com_delete (), com_help (), com_cd (), com_quit ();
 | |
| 
 | |
| /* A structure which contains information on the commands this program
 | |
|    can understand. */
 | |
| 
 | |
| typedef struct @{
 | |
|   char *name;			/* User printable name of the function. */
 | |
|   Function *func;		/* Function to call to do the job. */
 | |
|   char *doc;			/* Documentation for this function.  */
 | |
| @} COMMAND;
 | |
| 
 | |
| COMMAND commands[] = @{
 | |
|   @{ "cd", com_cd, "Change to directory DIR" @},
 | |
|   @{ "delete", com_delete, "Delete FILE" @},
 | |
|   @{ "help", com_help, "Display this text" @},
 | |
|   @{ "?", com_help, "Synonym for `help'" @},
 | |
|   @{ "list", com_list, "List files in DIR" @},
 | |
|   @{ "ls", com_list, "Synonym for `list'" @},
 | |
|   @{ "pwd", com_pwd, "Print the current working directory" @},
 | |
|   @{ "quit", com_quit, "Quit using Fileman" @},
 | |
|   @{ "rename", com_rename, "Rename FILE to NEWNAME" @},
 | |
|   @{ "stat", com_stat, "Print out statistics on FILE" @},
 | |
|   @{ "view", com_view, "View the contents of FILE" @},
 | |
|   @{ (char *)NULL, (Function *)NULL, (char *)NULL @}
 | |
| @};
 | |
| 
 | |
| /* Forward declarations. */
 | |
| char *stripwhite ();
 | |
| COMMAND *find_command ();
 | |
| 
 | |
| /* The name of this program, as taken from argv[0]. */
 | |
| char *progname;
 | |
| 
 | |
| /* When non-zero, this global means the user is done using this program. */
 | |
| int done;
 | |
| 
 | |
| char *
 | |
| dupstr (s)
 | |
|      int s;
 | |
| @{
 | |
|   char *r;
 | |
| 
 | |
|   r = xmalloc (strlen (s) + 1);
 | |
|   strcpy (r, s);
 | |
|   return (r);
 | |
| @}
 | |
| 
 | |
| main (argc, argv)
 | |
|      int argc;
 | |
|      char **argv;
 | |
| @{
 | |
|   char *line, *s;
 | |
| 
 | |
|   progname = argv[0];
 | |
| 
 | |
|   initialize_readline ();	/* Bind our completer. */
 | |
| 
 | |
|   /* Loop reading and executing lines until the user quits. */
 | |
|   for ( ; done == 0; )
 | |
|     @{
 | |
|       line = readline ("FileMan: ");
 | |
| 
 | |
|       if (!line)
 | |
|         break;
 | |
| 
 | |
|       /* Remove leading and trailing whitespace from the line.
 | |
|          Then, if there is anything left, add it to the history list
 | |
|          and execute it. */
 | |
|       s = stripwhite (line);
 | |
| 
 | |
|       if (*s)
 | |
|         @{
 | |
|           add_history (s);
 | |
|           execute_line (s);
 | |
|         @}
 | |
| 
 | |
|       free (line);
 | |
|     @}
 | |
|   exit (0);
 | |
| @}
 | |
| 
 | |
| /* Execute a command line. */
 | |
| int
 | |
| execute_line (line)
 | |
|      char *line;
 | |
| @{
 | |
|   register int i;
 | |
|   COMMAND *command;
 | |
|   char *word;
 | |
| 
 | |
|   /* Isolate the command word. */
 | |
|   i = 0;
 | |
|   while (line[i] && whitespace (line[i]))
 | |
|     i++;
 | |
|   word = line + i;
 | |
| 
 | |
|   while (line[i] && !whitespace (line[i]))
 | |
|     i++;
 | |
| 
 | |
|   if (line[i])
 | |
|     line[i++] = '\0';
 | |
| 
 | |
|   command = find_command (word);
 | |
| 
 | |
|   if (!command)
 | |
|     @{
 | |
|       fprintf (stderr, "%s: No such command for FileMan.\n", word);
 | |
|       return (-1);
 | |
|     @}
 | |
| 
 | |
|   /* Get argument to command, if any. */
 | |
|   while (whitespace (line[i]))
 | |
|     i++;
 | |
| 
 | |
|   word = line + i;
 | |
| 
 | |
|   /* Call the function. */
 | |
|   return ((*(command->func)) (word));
 | |
| @}
 | |
| 
 | |
| /* Look up NAME as the name of a command, and return a pointer to that
 | |
|    command.  Return a NULL pointer if NAME isn't a command name. */
 | |
| COMMAND *
 | |
| find_command (name)
 | |
|      char *name;
 | |
| @{
 | |
|   register int i;
 | |
| 
 | |
|   for (i = 0; commands[i].name; i++)
 | |
|     if (strcmp (name, commands[i].name) == 0)
 | |
|       return (&commands[i]);
 | |
| 
 | |
|   return ((COMMAND *)NULL);
 | |
| @}
 | |
| 
 | |
| /* Strip whitespace from the start and end of STRING.  Return a pointer
 | |
|    into STRING. */
 | |
| char *
 | |
| stripwhite (string)
 | |
|      char *string;
 | |
| @{
 | |
|   register char *s, *t;
 | |
| 
 | |
|   for (s = string; whitespace (*s); s++)
 | |
|     ;
 | |
|     
 | |
|   if (*s == 0)
 | |
|     return (s);
 | |
| 
 | |
|   t = s + strlen (s) - 1;
 | |
|   while (t > s && whitespace (*t))
 | |
|     t--;
 | |
|   *++t = '\0';
 | |
| 
 | |
|   return s;
 | |
| @}
 | |
| 
 | |
| /* **************************************************************** */
 | |
| /*                                                                  */
 | |
| /*                  Interface to Readline Completion                */
 | |
| /*                                                                  */
 | |
| /* **************************************************************** */
 | |
| 
 | |
| char *command_generator ();
 | |
| char **fileman_completion ();
 | |
| 
 | |
| /* Tell the GNU Readline library how to complete.  We want to try to complete
 | |
|    on command names if this is the first word in the line, or on filenames
 | |
|    if not. */
 | |
| initialize_readline ()
 | |
| @{
 | |
|   /* Allow conditional parsing of the ~/.inputrc file. */
 | |
|   rl_readline_name = "FileMan";
 | |
| 
 | |
|   /* Tell the completer that we want a crack first. */
 | |
|   rl_attempted_completion_function = (CPPFunction *)fileman_completion;
 | |
| @}
 | |
| 
 | |
| /* Attempt to complete on the contents of TEXT.  START and END bound the
 | |
|    region of rl_line_buffer that contains the word to complete.  TEXT is
 | |
|    the word to complete.  We can use the entire contents of rl_line_buffer
 | |
|    in case we want to do some simple parsing.  Return the array of matches,
 | |
|    or NULL if there aren't any. */
 | |
| char **
 | |
| fileman_completion (text, start, end)
 | |
|      char *text;
 | |
|      int start, end;
 | |
| @{
 | |
|   char **matches;
 | |
| 
 | |
|   matches = (char **)NULL;
 | |
| 
 | |
|   /* If this word is at the start of the line, then it is a command
 | |
|      to complete.  Otherwise it is the name of a file in the current
 | |
|      directory. */
 | |
|   if (start == 0)
 | |
|     matches = completion_matches (text, command_generator);
 | |
| 
 | |
|   return (matches);
 | |
| @}
 | |
| 
 | |
| /* Generator function for command completion.  STATE lets us know whether
 | |
|    to start from scratch; without any state (i.e. STATE == 0), then we
 | |
|    start at the top of the list. */
 | |
| char *
 | |
| command_generator (text, state)
 | |
|      char *text;
 | |
|      int state;
 | |
| @{
 | |
|   static int list_index, len;
 | |
|   char *name;
 | |
| 
 | |
|   /* If this is a new word to complete, initialize now.  This includes
 | |
|      saving the length of TEXT for efficiency, and initializing the index
 | |
|      variable to 0. */
 | |
|   if (!state)
 | |
|     @{
 | |
|       list_index = 0;
 | |
|       len = strlen (text);
 | |
|     @}
 | |
| 
 | |
|   /* Return the next name which partially matches from the command list. */
 | |
|   while (name = commands[list_index].name)
 | |
|     @{
 | |
|       list_index++;
 | |
| 
 | |
|       if (strncmp (name, text, len) == 0)
 | |
|         return (dupstr(name));
 | |
|     @}
 | |
| 
 | |
|   /* If no names matched, then return NULL. */
 | |
|   return ((char *)NULL);
 | |
| @}
 | |
| 
 | |
| /* **************************************************************** */
 | |
| /*                                                                  */
 | |
| /*                       FileMan Commands                           */
 | |
| /*                                                                  */
 | |
| /* **************************************************************** */
 | |
| 
 | |
| /* String to pass to system ().  This is for the LIST, VIEW and RENAME
 | |
|    commands. */
 | |
| static char syscom[1024];
 | |
| 
 | |
| /* List the file(s) named in arg. */
 | |
| com_list (arg)
 | |
|      char *arg;
 | |
| @{
 | |
|   if (!arg)
 | |
|     arg = "";
 | |
| 
 | |
|   sprintf (syscom, "ls -FClg %s", arg);
 | |
|   return (system (syscom));
 | |
| @}
 | |
| 
 | |
| com_view (arg)
 | |
|      char *arg;
 | |
| @{
 | |
|   if (!valid_argument ("view", arg))
 | |
|     return 1;
 | |
| 
 | |
|   sprintf (syscom, "more %s", arg);
 | |
|   return (system (syscom));
 | |
| @}
 | |
| 
 | |
| com_rename (arg)
 | |
|      char *arg;
 | |
| @{
 | |
|   too_dangerous ("rename");
 | |
|   return (1);
 | |
| @}
 | |
| 
 | |
| com_stat (arg)
 | |
|      char *arg;
 | |
| @{
 | |
|   struct stat finfo;
 | |
| 
 | |
|   if (!valid_argument ("stat", arg))
 | |
|     return (1);
 | |
| 
 | |
|   if (stat (arg, &finfo) == -1)
 | |
|     @{
 | |
|       perror (arg);
 | |
|       return (1);
 | |
|     @}
 | |
| 
 | |
|   printf ("Statistics for `%s':\n", arg);
 | |
| 
 | |
|   printf ("%s has %d link%s, and is %d byte%s in length.\n", arg,
 | |
|           finfo.st_nlink,
 | |
|           (finfo.st_nlink == 1) ? "" : "s",
 | |
|           finfo.st_size,
 | |
|           (finfo.st_size == 1) ? "" : "s");
 | |
|   printf ("Inode Last Change at: %s", ctime (&finfo.st_ctime));
 | |
|   printf ("      Last access at: %s", ctime (&finfo.st_atime));
 | |
|   printf ("    Last modified at: %s", ctime (&finfo.st_mtime));
 | |
|   return (0);
 | |
| @}
 | |
| 
 | |
| com_delete (arg)
 | |
|      char *arg;
 | |
| @{
 | |
|   too_dangerous ("delete");
 | |
|   return (1);
 | |
| @}
 | |
| 
 | |
| /* Print out help for ARG, or for all of the commands if ARG is
 | |
|    not present. */
 | |
| com_help (arg)
 | |
|      char *arg;
 | |
| @{
 | |
|   register int i;
 | |
|   int printed = 0;
 | |
| 
 | |
|   for (i = 0; commands[i].name; i++)
 | |
|     @{
 | |
|       if (!*arg || (strcmp (arg, commands[i].name) == 0))
 | |
|         @{
 | |
|           printf ("%s\t\t%s.\n", commands[i].name, commands[i].doc);
 | |
|           printed++;
 | |
|         @}
 | |
|     @}
 | |
| 
 | |
|   if (!printed)
 | |
|     @{
 | |
|       printf ("No commands match `%s'.  Possibilties are:\n", arg);
 | |
| 
 | |
|       for (i = 0; commands[i].name; i++)
 | |
|         @{
 | |
|           /* Print in six columns. */
 | |
|           if (printed == 6)
 | |
|             @{
 | |
|               printed = 0;
 | |
|               printf ("\n");
 | |
|             @}
 | |
| 
 | |
|           printf ("%s\t", commands[i].name);
 | |
|           printed++;
 | |
|         @}
 | |
| 
 | |
|       if (printed)
 | |
|         printf ("\n");
 | |
|     @}
 | |
|   return (0);
 | |
| @}
 | |
| 
 | |
| /* Change to the directory ARG. */
 | |
| com_cd (arg)
 | |
|      char *arg;
 | |
| @{
 | |
|   if (chdir (arg) == -1)
 | |
|     @{
 | |
|       perror (arg);
 | |
|       return 1;
 | |
|     @}
 | |
| 
 | |
|   com_pwd ("");
 | |
|   return (0);
 | |
| @}
 | |
| 
 | |
| /* Print out the current working directory. */
 | |
| com_pwd (ignore)
 | |
|      char *ignore;
 | |
| @{
 | |
|   char dir[1024], *s;
 | |
| 
 | |
|   s = getwd (dir);
 | |
|   if (s == 0)
 | |
|     @{
 | |
|       printf ("Error getting pwd: %s\n", dir);
 | |
|       return 1;
 | |
|     @}
 | |
| 
 | |
|   printf ("Current directory is %s\n", dir);
 | |
|   return 0;
 | |
| @}
 | |
| 
 | |
| /* The user wishes to quit using this program.  Just set DONE non-zero. */
 | |
| com_quit (arg)
 | |
|      char *arg;
 | |
| @{
 | |
|   done = 1;
 | |
|   return (0);
 | |
| @}
 | |
| 
 | |
| /* Function which tells you that you can't do this. */
 | |
| too_dangerous (caller)
 | |
|      char *caller;
 | |
| @{
 | |
|   fprintf (stderr,
 | |
|            "%s: Too dangerous for me to distribute.  Write it yourself.\n",
 | |
|            caller);
 | |
| @}
 | |
| 
 | |
| /* Return non-zero if ARG is a valid argument for CALLER, else print
 | |
|    an error message and return zero. */
 | |
| int
 | |
| valid_argument (caller, arg)
 | |
|      char *caller, *arg;
 | |
| @{
 | |
|   if (!arg || !*arg)
 | |
|     @{
 | |
|       fprintf (stderr, "%s: Argument required.\n", caller);
 | |
|       return (0);
 | |
|     @}
 | |
| 
 | |
|   return (1);
 | |
| @}
 | |
| @end smallexample
 | 
