1012 lines
32 KiB
Text
1012 lines
32 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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@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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Copyright (C) 1988 Free Software Foundation, Inc.
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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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@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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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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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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@node Programming with GNU Readline
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@chapter Programming with GNU Readline
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This manual describes the interface between the GNU Readline Library and
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user programs. If you are a programmer, and you wish to include the
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features found in GNU Readline in your own programs, such as completion,
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line editing, and interactive history manipulation, this documentation
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is for you.
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@menu
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* Default Behaviour:: Using the default behaviour of Readline.
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* Custom Functions:: Adding your own functions to Readline.
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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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@node Default Behaviour
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@section Default Behaviour
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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 ()}.
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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 which @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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@example
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@code{char *readline (char *@var{prompt});}
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@end example
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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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in order to read a line of text from the user.
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The line which is returned has the final newline removed, so only the
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text of the line remains.
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If 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 was typed.
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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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@example
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@code{add_history (line)};
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@end example
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For full details on the GNU History Library, see the associated manual.
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It is polite to avoid saving empty lines on the history list, since it
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is rare than someone has 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:
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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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/* Read a string, and return a pointer to it. Returns NULL on EOF. */
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char *
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do_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 != (char *)NULL)
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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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/* Get a line from the user. */
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line_read = readline ("");
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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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return (line_read);
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@}
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@end example
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The above code 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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@findex rl_bind_key ()
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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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@code{rl_bind_key ()} takes 2 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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run when @var{key} is pressed. Binding @key{TAB} to @code{rl_insert ()}
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makes @key{TAB} just 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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@example
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@code{rl_bind_key ('\t', rl_insert);}
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@end example
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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, etc.
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@node Custom Functions
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@section Custom Functions
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Readline provides a great 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 in within the Readline library which allow a user program to add
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customized functionality to Readline.
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@menu
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* The Function Type:: C declarations to make code readable.
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* Function Naming:: How to give a function you write a name.
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* Keymaps:: Making keymaps.
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* Binding Keys:: Changing Keymaps.
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* Function Writing:: Variables and calling conventions.
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* Allowing Undoing:: How to make your functions undoable.
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@end menu
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@node The Function Type
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@subsection The Function Type
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For the sake of readabilty, we declare a new type of object, called
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@dfn{Function}. A @code{Function} is a C language function which
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returns an @code{int}. The type declaration for @code{Function} is:
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@noindent
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@code{typedef int Function ();}
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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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@code{int (*)()func;}
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we have
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@code{Function *func;}
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@node Function Naming
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@subsection Naming a Function
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The user can dynamically change the bindings of keys while using
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Readline. This is done by representing the function with a descriptive
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name. The user is able to type the descriptive name when referring to
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the function. Thus, in an init file, one might find
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@example
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Meta-Rubout: backward-kill-word
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@end example
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This binds the keystroke @key{Meta-Rubout} to the function
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@emph{descriptively} named @code{backward-kill-word}. You, as the
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programmer, should bind the functions you write to descriptive names as
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well. Readline provides a function for doing that:
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@defun rl_add_defun (char *name, Function *function, int key)
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Add @var{name} to the list of named functions. Make @var{function} be
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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 ()}.
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@end defun
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Using this function alone is sufficient for most applications. It is
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the recommended way to add a few functions to the default functions that
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Readline has built in already. If you need to do more or different
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things than adding a function to Readline, you may need to use the
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underlying functions described below.
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@node Keymaps
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@subsection Selecting a Keymap
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Key bindings take place on a @dfn{keymap}. The keymap is the
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association between the keys that the user types and the functions that
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get run. You can make your own keymaps, copy existing keymaps, and tell
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Readline which keymap to use.
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@defun {Keymap rl_make_bare_keymap} ()
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Returns a new, empty keymap. The space for the keymap is allocated with
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@code{malloc ()}; you should @code{free ()} it when you are done.
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@end defun
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@defun {Keymap rl_copy_keymap} (Keymap map)
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Return a new keymap which is a copy of @var{map}.
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@end defun
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@defun {Keymap rl_make_keymap} ()
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Return a new keymap with the printing characters bound to rl_insert,
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the lowercase Meta characters bound to run their equivalents, and
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the Meta digits bound to produce numeric arguments.
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@end defun
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@node Binding Keys
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@subsection Binding Keys
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You associate keys with functions through the keymap. Here are
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functions for doing that.
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@defun {int rl_bind_key} (int key, Function *function)
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Binds @var{key} to @var{function} in the currently selected keymap.
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Returns non-zero in the case of an invalid @var{key}.
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@end defun
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@defun {int rl_bind_key_in_map} (int key, Function *function, Keymap map)
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Bind @var{key} to @var{function} in @var{map}. Returns non-zero in the case
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of an invalid @var{key}.
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@end defun
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@defun {int rl_unbind_key} (int key)
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Make @var{key} do nothing in the currently selected keymap.
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Returns non-zero in case of error.
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@end defun
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@defun {int rl_unbind_key_in_map} (int key, Keymap map)
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Make @var{key} be bound to the null function in @var{map}.
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Returns non-zero in case of error.
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@end defun
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@defun rl_generic_bind (int type, char *keyseq, char *data, Keymap map)
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Bind the key sequence represented by the string @var{keyseq} to the arbitrary
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pointer @var{data}. @var{type} says what kind of data is pointed to by
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@var{data}; right now this can be a function (@code{ISFUNC}), a macro
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(@code{ISMACR}), or a keymap (@code{ISKMAP}). This makes new keymaps as
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necessary. The initial place to do bindings is in @var{map}.
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@end defun
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@node Function Writing
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@subsection Writing a New Function
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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 gathered so far.
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@defvar {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 this, but see Undoing, below.
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@end defvar
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@defvar {int rl_point}
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The offset of the current cursor position in @var{rl_line_buffer}.
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@end defvar
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@defvar {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, then @code{rl_point} and
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@code{rl_end} are equal.
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@end defvar
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The calling sequence for a command @code{foo} looks like
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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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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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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, other
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functions as a flag, and some choose to 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 a negative argument as well as a positive
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argument. At the very least, it should be aware that it can be passed a
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negative argument.
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@node Allowing Undoing
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@subsection Allowing Undoing
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Supporting the undo command is a painless thing to do, and makes your
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functions much more useful to the end user. It is certainly easy to try
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something if you know you can undo it. I could use an undo function for
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the stock market.
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If your function simply inserts text once, or deletes text once, and it
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calls @code{rl_insert_text ()} or @code{rl_delete_text ()} to do it, then
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undoing is already done for you automatically, and you can safely skip
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this section.
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If you do multiple insertions or multiple deletions, or any combination
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of these operations, you should group them together into one operation.
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This can be done with @code{rl_begin_undo_group ()} and
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@code{rl_end_undo_group ()}.
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@defun rl_begin_undo_group ()
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Begins saving undo information in a group construct. The undo
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information usually comes from calls to @code{rl_insert_text ()} and
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@code{rl_delete_text ()}, but they could be direct calls to
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@code{rl_add_undo ()}.
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@end defun
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@defun rl_end_undo_group ()
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Closes the current undo group started with @code{rl_begin_undo_group
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()}. There should be exactly one call to @code{rl_end_undo_group ()}
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for every call to @code{rl_begin_undo_group ()}.
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@end defun
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Finally, if you neither insert nor delete text, but directly modify the
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existing text (e.g. change its case), you call @code{rl_modifying ()}
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once, just before you modify the text. You must supply the indices of
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the text range that you are going to modify.
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@defun rl_modifying (int start, int end)
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Tell Readline to save the text between @var{start} and @var{end} as a
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single undo unit. It is assumed that subsequent to this call you will
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modify that range of text in some way.
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@end defun
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@subsection An Example
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Here is a function which changes lowercase characters to the uppercase
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equivalents, and uppercase characters to the lowercase equivalents. If
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this function was bound to @samp{M-c}, then typing @samp{M-c} would
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change the case of the character under point. Typing @samp{10 M-c}
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would change the case of the following 10 characters, leaving the cursor on
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the last character changed.
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@example
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/* Invert the case of the COUNT following characters. */
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invert_case_line (count, key)
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int count, key;
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@{
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register int start, end;
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start = rl_point;
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if (count < 0)
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@{
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direction = -1;
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count = -count;
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@}
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else
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direction = 1;
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/* Find the end of the range to modify. */
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end = start + (count * direction);
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/* Force it to be within range. */
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if (end > rl_end)
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end = rl_end;
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else if (end < 0)
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end = -1;
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if (start > end)
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@{
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int temp = start;
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start = end;
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end = temp;
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@}
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if (start == end)
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return;
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/* Tell readline that we are modifying the line, so save the undo
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information. */
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rl_modifying (start, end);
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for (; start != end; start += direction)
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@{
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if (uppercase_p (rl_line_buffer[start]))
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rl_line_buffer[start] = to_lower (rl_line_buffer[start]);
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else if (lowercase_p (rl_line_buffer[start]))
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rl_line_buffer[start] = to_upper (rl_line_buffer[start]);
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@}
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/* Move point to on top of the last character changed. */
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rl_point = end - direction;
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@}
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@end example
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@node Custom Completers
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@section Custom Completers
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Typically, a program that reads commands from the user has a way of
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disambiguating commands and data. If your program is one of these, then
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it can provide completion for either commands, or data, or both commands
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and data. The following sections describe how your program and Readline
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cooperate to provide this service to end users.
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@menu
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|
* How Completing Works:: The logic used to do completion.
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|
* Completion Functions:: Functions provided by Readline.
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* Completion Variables:: Variables which control completion.
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* A Short Completion Example:: An example of writing completer subroutines.
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@end menu
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@node How Completing Works
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@subsection How Completing Works
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In order to complete some text, the full list of possible completions
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must be available. That is to say, it is not possible to accurately
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expand a partial word without knowing what all of the possible words
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that make sense in that context are. The GNU Readline library provides
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the user interface to completion, and additionally, two of the most common
|
|
completion functions; filename and username. For completing other types
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of text, you must write your own completion function. This section
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describes exactly what those functions must do, and provides an example
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function.
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There are three major functions used to perform completion:
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@enumerate
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@item
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The user-interface function @code{rl_complete ()}. This function is
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|
called interactively with the same calling conventions as other
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|
functions in readline intended for interactive use; i.e. @var{count},
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|
and @var{invoking-key}. It isolates the word to be completed and calls
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|
@code{completion_matches ()} to generate a list of possible completions.
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|
It then either lists the possible completions or actually performs the
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|
completion, depending on which behaviour is desired.
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@item
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The internal function @code{completion_matches ()} uses your
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@dfn{generator} function to generate the list of possible matches, and
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then returns the array of these matches. You should place the address
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of your generator function in @code{rl_completion_entry_function}.
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@item
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The generator function is called repeatedly from
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@code{completion_matches ()}, returning a string each time. The
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arguments to the generator function are @var{text} and @var{state}.
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@var{text} is the partial word to be completed. @var{state} is zero the
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first time the function is called, and a positive non-zero integer for
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each subsequent call. When the generator function returns @code{(char
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*)NULL} this signals @code{completion_matches ()} that there are no more
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possibilities left.
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@end enumerate
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@defun rl_complete (int ignore, int invoking_key)
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Complete the word at or before point. You have supplied the function
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that does the initial simple matching selection algorithm (see
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@code{completion_matches ()}). The default is to do filename completion.
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@end defun
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Note that @code{rl_complete ()} has the identical calling conventions as
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|
any other key-invokable function; this is because by default it is bound
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to the @samp{TAB} key.
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@defvar {Function *rl_completion_entry_function}
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|
This is a pointer to the generator function for @code{completion_matches
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|
()}. If the value of @code{rl_completion_entry_function} is
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|
@code{(Function *)NULL} then the default filename generator function is
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|
used, namely @code{filename_entry_function ()}.
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|
@end defvar
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@node Completion Functions
|
|
@subsection Completion Functions
|
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|
|
Here is the complete list of callable completion functions present in
|
|
Readline.
|
|
|
|
@defun 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.
|
|
@end defun
|
|
|
|
@defun 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. This just calls @code{rl_complete_internal ()} with an
|
|
argument of @samp{TAB}.
|
|
@end defun
|
|
|
|
@defun rl_possible_completions ()
|
|
List the possible completions. See description of @code{rl_complete
|
|
()}. This just calls @code{rl_complete_internal ()} with an argument of
|
|
@samp{?}.
|
|
@end defun
|
|
|
|
@defun {char **completion_matches} (char *text, char *(*entry_function) ())
|
|
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_function} 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. It returns a @code{NULL} pointer to the caller when there are
|
|
no more matches.
|
|
@end defun
|
|
|
|
@defun {char *filename_completion_function} (char *text, int state)
|
|
A generator function for filename completion in the general case. Note
|
|
that completion in the Bash shell is a little different because of all
|
|
the pathnames that must be followed when looking up the completion for a
|
|
command.
|
|
@end defun
|
|
|
|
@defun {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{~}).
|
|
@end defun
|
|
|
|
@node Completion Variables
|
|
@subsection Completion Variables
|
|
|
|
@defvar {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 defvar
|
|
|
|
@defvar {Function *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} 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 defvar
|
|
|
|
@defvar {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 defvar
|
|
|
|
@defvar {char *rl_basic_word_break_characters}
|
|
The basic list of characters that signal a break between words for the
|
|
completer routine. The contents of this variable is what breaks words
|
|
in the Bash shell, i.e. " \t\n\"\\'`@@$><=;|&@{(".
|
|
@end defvar
|
|
|
|
@defvar {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 contents of
|
|
@code{rl_basic_word_break_characters}.
|
|
@end defvar
|
|
|
|
@defvar {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.
|
|
@end defvar
|
|
|
|
@defvar {int rl_ignore_completion_duplicates}
|
|
If non-zero, then disallow duplicates in the matches. Default is 1.
|
|
@end defvar
|
|
|
|
@defvar {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.
|
|
@end defvar
|
|
|
|
@defvar {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 @code{(char *)} known as
|
|
@var{matches} in the code. The 1st element (@code{matches[0]}) is the
|
|
maximal substring that is common to all matches. This function can
|
|
re-arrange the list of matches as required, but each deleted element of
|
|
the array must be @code{free()}'d.
|
|
@end defvar
|
|
|
|
@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{readline/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 <readline/readline.h>
|
|
#include <readline/history.h>
|
|
#include <sys/types.h>
|
|
#include <sys/file.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/errno.h>
|
|
|
|
/* 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 @}
|
|
@};
|
|
|
|
/* 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 = 0;
|
|
@page
|
|
main (argc, argv)
|
|
int argc;
|
|
char **argv;
|
|
@{
|
|
progname = argv[0];
|
|
|
|
initialize_readline (); /* Bind our completer. */
|
|
|
|
/* Loop reading and executing lines until the user quits. */
|
|
while (!done)
|
|
@{
|
|
char *line;
|
|
|
|
line = readline ("FileMan: ");
|
|
|
|
if (!line)
|
|
@{
|
|
done = 1; /* Encountered EOF at top level. */
|
|
@}
|
|
else
|
|
@{
|
|
/* Remove leading and trailing whitespace from the line.
|
|
Then, if there is anything left, add it to the history list
|
|
and execute it. */
|
|
stripwhite (line);
|
|
|
|
if (*line)
|
|
@{
|
|
add_history (line);
|
|
execute_line (line);
|
|
@}
|
|
@}
|
|
|
|
if (line)
|
|
free (line);
|
|
@}
|
|
exit (0);
|
|
@}
|
|
|
|
/* Execute a command line. */
|
|
execute_line (line)
|
|
char *line;
|
|
@{
|
|
register int i;
|
|
COMMAND *find_command (), *command;
|
|
char *word;
|
|
|
|
/* Isolate the command word. */
|
|
i = 0;
|
|
while (line[i] && !whitespace (line[i]))
|
|
i++;
|
|
|
|
word = line;
|
|
|
|
if (line[i])
|
|
line[i++] = '\0';
|
|
|
|
command = find_command (word);
|
|
|
|
if (!command)
|
|
@{
|
|
fprintf (stderr, "%s: No such command for FileMan.\n", word);
|
|
return;
|
|
@}
|
|
|
|
/* Get argument to command, if any. */
|
|
while (whitespace (line[i]))
|
|
i++;
|
|
|
|
word = line + i;
|
|
|
|
/* Call the function. */
|
|
(*(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. */
|
|
stripwhite (string)
|
|
char *string;
|
|
@{
|
|
register int i = 0;
|
|
|
|
while (whitespace (string[i]))
|
|
i++;
|
|
|
|
if (i)
|
|
strcpy (string, string + i);
|
|
|
|
i = strlen (string) - 1;
|
|
|
|
while (i > 0 && whitespace (string[i]))
|
|
i--;
|
|
|
|
string[++i] = '\0';
|
|
@}
|
|
@page
|
|
/* **************************************************************** */
|
|
/* */
|
|
/* Interface to Readline 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 ()
|
|
@{
|
|
char **fileman_completion ();
|
|
|
|
/* Allow conditional parsing of the ~/.inputrc file. */
|
|
rl_readline_name = "FileMan";
|
|
|
|
/* Tell the completer that we want a crack first. */
|
|
rl_attempted_completion_function = (Function *)fileman_completion;
|
|
@}
|
|
|
|
/* Attempt to complete on the contents of TEXT. START and END show the
|
|
region of TEXT that contains the word to complete. We can use the
|
|
entire line 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;
|
|
char *command_generator ();
|
|
|
|
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 (name);
|
|
@}
|
|
|
|
/* If no names matched, then return NULL. */
|
|
return ((char *)NULL);
|
|
@}
|
|
@page
|
|
/* **************************************************************** */
|
|
/* */
|
|
/* 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);
|
|
system (syscom);
|
|
@}
|
|
|
|
com_view (arg)
|
|
char *arg;
|
|
@{
|
|
if (!valid_argument ("view", arg))
|
|
return;
|
|
|
|
sprintf (syscom, "cat %s | more", arg);
|
|
system (syscom);
|
|
@}
|
|
|
|
com_rename (arg)
|
|
char *arg;
|
|
@{
|
|
too_dangerous ("rename");
|
|
@}
|
|
|
|
com_stat (arg)
|
|
char *arg;
|
|
@{
|
|
struct stat finfo;
|
|
|
|
if (!valid_argument ("stat", arg))
|
|
return;
|
|
|
|
if (stat (arg, &finfo) == -1)
|
|
@{
|
|
perror (arg);
|
|
return;
|
|
@}
|
|
|
|
printf ("Statistics for `%s':\n", arg);
|
|
|
|
printf ("%s has %d link%s, and is %d bytes in length.\n", arg,
|
|
finfo.st_nlink, (finfo.st_nlink == 1) ? "" : "s", finfo.st_size);
|
|
printf (" Created on: %s", ctime (&finfo.st_ctime));
|
|
printf (" Last access at: %s", ctime (&finfo.st_atime));
|
|
printf ("Last modified at: %s", ctime (&finfo.st_mtime));
|
|
@}
|
|
|
|
com_delete (arg)
|
|
char *arg;
|
|
@{
|
|
too_dangerous ("delete");
|
|
@}
|
|
|
|
/* 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");
|
|
@}
|
|
@}
|
|
|
|
/* Change to the directory ARG. */
|
|
com_cd (arg)
|
|
char *arg;
|
|
@{
|
|
if (chdir (arg) == -1)
|
|
perror (arg);
|
|
|
|
com_pwd ("");
|
|
@}
|
|
|
|
/* Print out the current working directory. */
|
|
com_pwd (ignore)
|
|
char *ignore;
|
|
@{
|
|
char dir[1024];
|
|
|
|
(void) getwd (dir);
|
|
|
|
printf ("Current directory is %s\n", dir);
|
|
@}
|
|
|
|
/* The user wishes to quit using this program. Just set DONE non-zero. */
|
|
com_quit (arg)
|
|
char *arg;
|
|
@{
|
|
done = 1;
|
|
@}
|
|
|
|
/* 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
|