carl.c

/* carl -- C Asynchronous Readline
 * Copyright (C) 2010 Dawid Ciężarkiewicz
 *
 * Originally part of xmppconsole <http://github.com/dpc/xmppconsole>
 * as io.c and io.h, but repackaged for general-purpose use, and with
 * a different namespace, by Aaron Griffith.
 *
 * For documentation, see carl.h.
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "carl.h"
#include <stdio.h>
#include <readline/readline.h>
#include <readline/history.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/select.h>

/* global status variables */
static fd_set carl_fds;
static const char* carl_prompt = NULL;
static int carl_echo = 1;
static int carl_running = 0;
static carl_callback_t carl_callback_func = NULL;
static void* carl_callback_data = NULL;

static void carl_handle_line_fake(char* line)
{
	if (line != NULL)
	{
		if (carl_running)
		{
			rl_set_prompt(carl_prompt);
			rl_already_prompted = 1;
		}
		return;
	}
	carl_running = 0;

	rl_set_prompt("");
	rl_replace_line("", 0);
	rl_redisplay();
}

static int carl_handle_enter(int x, int y)
{
	char* line = NULL;

	line = rl_copy_text(0, rl_end);
	rl_set_prompt("");
	rl_replace_line("", 1);
	rl_redisplay();
	
	if (carl_echo)
		carl_printfln("%s%s", carl_prompt, line);
	
	if (carl_callback_func != NULL)
		(*carl_callback_func)(line, carl_callback_data);

	if (strcmp(line, "") != 0)
	{
		add_history(line);
	}
	free(line);

	rl_set_prompt(carl_prompt);
	return 0;
}

void carl_init()
{
	/* sane defaults */
	carl_prompt_set("");
	carl_echo_set(1);
	carl_callback_set(NULL, NULL);
	
	FD_ZERO(&carl_fds);
	rl_callback_handler_install(carl_prompt, carl_handle_line_fake);
	
	if (rl_bind_key(RETURN, carl_handle_enter))
	{
		carl_printfln("failed to bind RETURN");
		abort();
	}
	
	carl_running = 1;
}

int carl_process()
{
	int count;
	struct timeval t;

	if (carl_running == 0)
		return 0;

	t.tv_sec = 0;
	t.tv_usec = 0;

	FD_SET(STDIN_FILENO, &carl_fds);
	count = select(FD_SETSIZE, &carl_fds, NULL, NULL, &t);
	if (count < 0)
	{
		carl_printfln("select() returned an error");
		abort();
	} else if (count == 0) {
		return carl_running;
	}
	rl_callback_read_char();
	
	return carl_running;
}

void carl_deinit()
{
	carl_running = 0;
	rl_callback_handler_remove();
}

void carl_prompt_set(const char* p)
{
	carl_prompt = p;
	rl_set_prompt(carl_prompt);
	rl_redisplay();
}

const char* carl_prompt_get()
{
	return carl_prompt;
}

void carl_echo_set(int echo)
{
	carl_echo = echo;
}

int carl_echo_get()
{
	return carl_echo;
}

void carl_callback_set(carl_callback_t func, void* userdata)
{
	carl_callback_func = func;
	carl_callback_data = userdata;
}

carl_callback_t carl_callback_get()
{
	return carl_callback_func;
}

void* carl_callback_userdata_get()
{
	return carl_callback_data;
}

typedef void (*print_func)(void*);

static void carl_async_print(print_func func, void* data)
{
	char* saved_line;
	int saved_point;

	saved_point = rl_point;
	saved_line = rl_copy_text(0, rl_end);
	
	rl_save_prompt();
	rl_set_prompt("");
	rl_replace_line("", 0);
	rl_redisplay();
	
	(*func)(data);
	
	rl_replace_line(saved_line, 0);
	if (carl_running)
		rl_set_prompt(carl_prompt);
	rl_restore_prompt();
	rl_point = saved_point;
	rl_forced_update_display();
	
	free(saved_line);
}

struct carl_async_func_data
{
	const char* fmt;
	va_list args;
};

static void carl_print_func(void* data)
{
	struct carl_async_func_data* d = (struct carl_async_func_data*)data;
	
	vprintf(d->fmt, d->args);
	printf("\n");
}

void carl_printfln(const char* const fmt, ...)
{
	va_list arg;
	va_start(arg, fmt);
	carl_vprintfln(fmt, arg);
	va_end(arg);
}

void carl_vprintfln(const char* const fmt, va_list arg)
{
	struct carl_async_func_data d;
	d.fmt = fmt;
	va_copy(d.args, arg);

	carl_async_print(carl_print_func, &d);
}

struct carl_async_pass_data
{
	const char* prompt;
	char* pass;
};

static void carl_getpass_func(void* data)
{
	struct carl_async_pass_data* d = (struct carl_async_pass_data*)(data);

	d->pass = getpass(d->prompt);
	rl_already_prompted = 1;
}

char* carl_getpass(const char* p)
{
	struct carl_async_pass_data d;
	d.pass = NULL;
	d.prompt = p;
	
	rl_callback_handler_remove();
	carl_async_print(carl_getpass_func, &d);
	rl_callback_handler_install(carl_prompt, carl_handle_line_fake);
	
	return d.pass;
}