Question

I’ve got a question about Readline Library.

I want to know if Readline can autocomplete filename from directories in a C program ?

I’ve searched and only seen command name completion.

thanks in advance.

EDIT: I’ve copy filename in an array.
These as functions that I use :
in the file rline.c, char *command_generator,char **tab_completion (const char *text, int start, int end),void initialize_readline (). I think I have to use char * filename_completion_function (char *text, int state) ? When I type on “tab” key, it calls nothing, bind() didn’t seem to be used. Do you know if I use right functions ?
thanks !!

Answer 1

Filename completion is a built-in feature of readline, you don’t need to populate filename lists etc. Here with readline 6.1 the following program allows filename completion by default.

#include <stdio.h>
#include <stdlib.h>

#include <readline/readline.h>
#include <readline/history.h>

int main()
{
    printf( "%s\n", readline( "test> " ) );
    return 0;
}

There are ways to customize this mechanism, e.g. you can specify some functions like rl_filename_quoting_function and rl_filename_dequoting_function to help readline provide proper filename quotation for your application.

I think you need to specify your version of readline if this doesn’t work for you. /etc/inputrc contents should be examined as well. Do you have bash, which uses readline? Does the filename completion work there as expected?
Anyway, info readline is a very good documentation provided you can use info itself 🙂 If not, look at Programming with GNU Readline.