Added some files

Makefile

+CC=cc
+CFLAGS=-c -Wall -Wextra -fPIC
+LDFLAGS=-lreadline
+LD=cc
+
+SRC=main.c loop.c interface.c
+OBJ=$(SRC:.c=.o)
+EXE=telegram
+
+all: $(SRC) $(EXE)
+	
+$(EXE): $(OBJ) 
+	$(LD) $(LDFLAGS) $(OBJ) -o $@
+
+.c.o:
+	$(CC) $(CFLAGS) $< -o $@
+

include.h

+#ifndef __INCLUDE_H__
+#define __INCLUDE_H__
+
+#define UU __attribute__ ((unused))
+
+#endif

interface.c

+#define _GNU_SOURCE 
+#include <readline/readline.h>
+#include <readline/history.h>
+
+#include <assert.h>
+#include <stdio.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include "include.h"
+char *default_prompt = ">";
+
+char *get_default_prompt (void) {
+  return default_prompt;
+}
+
+char *complete_none (const char *text UU, int state UU) {
+  return 0;
+}
+
+char *commands[] = {
+  "help",
+  "msg",
+  0 };
+
+int commands_flags[] = {
+  070,
+  072,
+};
+  
+char *a = 0;
+char **user_list = &a;
+char **chat_list = &a;
+
+int init_token (char **q) {
+  char *r = *q;
+  while (*r == ' ') { r ++; }
+  if (!*r) { return 0; }
+  q = &r;
+  return 1;
+}
+
+char *get_token (char **q, int *l) {
+  char *r = *q;
+  while (*r == ' ') { r ++; }
+  if (!*r) { 
+    q = &r; 
+    *l = 0;
+    return 0;
+  }
+  int neg = 0;
+  char *s = r;
+  while (*r && (*r != ' ' || neg)) {
+    if (*r == '\\') {
+      neg = 1 - neg;
+    } else {
+      neg = 0;
+    }
+  }
+  q = &r;
+  *l = r - s;
+  return s;
+}
+
+
+int get_complete_mode (void) {
+  char *q = rl_line_buffer;
+  if (!init_token (&q)) { return 0; }
+  int l = 0;
+  char *r = get_token (&q, &l);
+  if (!*q) { return 0; }
+  
+  char **command = commands;
+  int n = 0;
+  int flags = -1;
+  while (*command) {
+    if ((int)strlen (*command) == l && !memcmp (r, *command, l)) {
+      flags = commands_flags[n];
+      break;
+    }
+    n ++;
+    command ++;
+  }
+  if (flags == -1) {
+    return -1;
+  }
+  int s = 0;
+  while (1) {
+    get_token (&q, &l);
+    if (!*q) { return flags & 7; }
+    s ++;
+    if (s <= 4) { flags >>= 3; }
+  }
+}
+
+int complete_string_list (char **list, int index, const char *text, int len, char **R) {
+  index ++;
+  int cc = 0;
+  while (cc <= 1 && list[index] && strncmp (list[index], text, len)) {
+    index ++;
+    if (!list[index]) { index = 0; cc ++; }
+  }
+  if (list[index] && cc <= 1) {
+    *R = strdup (list[index]);
+    return index;
+  } else {
+    *R = 0;
+    return -1;
+  }
+}
+char *command_generator (const char *text, int state) {  
+  static int len, index, mode;
+
+  if (!state) {
+    len = strlen (text);
+    index = -1;
+     
+    rl_line_buffer[rl_point] = '\0'; /* the effect should be such
+			* that the cursor position
+			* is at the end of line for
+		  * the auto completion regex
+			* above (note the $ at end)
+			*/
+
+    mode = get_complete_mode ();
+  } else {
+    if (index == -1) { return 0; }
+  }
+
+  if (mode == -1) { return 0; }
+
+  char *R = 0;
+  switch (mode & 7) {
+  case 0:
+    index = complete_string_list (commands, index, text, len, &R);
+    return R;
+  case 1:
+    index = complete_string_list (user_list, index, text, len, &R);
+    return R;
+  case 2:
+    index = complete_string_list (chat_list, index, text, len, &R);
+    return R;
+  case 3:
+    return rl_filename_completion_function(text,state);
+  default:
+    return 0;
+  }
+}
+
+char **complete_text (char *text, int start UU, int end UU) {
+  return (char **) rl_completion_matches (text, command_generator);
+}
+
+void interpreter (char *line UU) {
+  assert (0);
+}

interface.h

+#ifndef __INTERFACE_H__
+#define __INTERFACE_H__
+char *get_default_prompt (void);
+char *complete_none (const char *text, int state);
+char **complete_text (char *text, int start, int end);
+void interpreter (char *line);
+#endif

loop.c

+#define READLINE_CALLBACKS
+
+#include <assert.h>
+#include <stdio.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <readline/readline.h>
+#include <readline/history.h>
+
+#include "interface.h"
+extern char *default_username;
+extern char *auth_token;
+void set_default_username (const char *s);
+
+
+
+int main_loop (void) {
+  assert (0);
+}
+
+int loop (void) {
+  size_t size = 0;
+  char *user = default_username;
+
+  if (!user && !auth_token) {
+    printf ("Telephone number (with '+' sign): ");         
+    if (getline (&user, &size, stdin) == -1) {
+  	  perror ("getline()");
+	    exit (EXIT_FAILURE);
+  	}
+    user[strlen (user) - 1] = '\0';      
+    set_default_username (user);
+  }
+  
+  fflush (stdin);
+
+  rl_callback_handler_install (get_default_prompt (), interpreter);
+  rl_attempted_completion_function = (CPPFunction *) complete_text;
+  rl_completion_entry_function = complete_none;
+
+  return main_loop ();
+}
+

loop.h

+#ifndef __LOOP_H__
+#define __LOOP_H__
+int loop (void);
+#endif

main.c

+/* 
+   main.c: main initialization file
+   
+   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 2, 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pwd.h>
+#include <termios.h>
+#include <unistd.h>
+#include <assert.h>
+#include <readline/readline.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <fcntl.h>
+
+#include "loop.h"
+
+#define PROGNAME "telegram-client"
+#define VERSION "0.01"
+
+#define CONFIG_DIRECTORY ".telegram/"
+#define CONFIG_FILE CONFIG_DIRECTORY "config"
+#define DOWNLOADS_DIRECTORY "downloads/"
+
+#define CONFIG_DIRECTORY_MODE 0700
+
+#define DEFAULT_CONFIG_CONTENTS     \
+  "# This is an empty config file\n" \
+  "# Feel free to put something here\n"
+
+char *default_username;
+int setup_mode;
+char *auth_token;
+
+void set_default_username (const char *s) {
+  if (default_username) { 
+    free (default_username);
+  }
+  default_username = strdup (s);
+}
+
+void set_setup_mode (void) {
+  setup_mode = 1;
+}
+
+
+/* {{{ TERMINAL */
+tcflag_t old_lflag;
+cc_t old_vtime;
+struct termios term;
+
+void get_terminal_attributes (void) {
+  if (tcgetattr (STDIN_FILENO, &term) < 0) {
+    perror ("tcgetattr()");
+    exit (EXIT_FAILURE);
+  }
+  old_lflag = term.c_lflag;
+  old_vtime = term.c_cc[VTIME];
+}
+/* }}} */
+
+char *get_home_directory (void) {
+  struct passwd *current_passwd;
+  uid_t user_id;
+  setpwent ();
+  user_id = getuid ();
+  while ((current_passwd = getpwent ())) {
+    if (current_passwd->pw_uid == user_id) {
+      return current_passwd->pw_dir;
+    }
+  }
+  return 0;
+}
+
+char *get_config_directory (void) {
+  char *config_directory;
+  int length = strlen (get_home_directory ()) + strlen (CONFIG_DIRECTORY) + 2;
+
+  config_directory = (char *) calloc (length, sizeof (char));
+  sprintf (config_directory, "%s/" CONFIG_DIRECTORY,
+	   get_home_directory ());
+
+  return config_directory;
+}
+
+char *get_config_filename (void) {
+  char *config_filename;
+  int length = strlen (get_home_directory ()) + strlen (CONFIG_FILE) + 2;
+
+  config_filename = (char *) calloc (length, sizeof (char));
+  sprintf (config_filename, "%s/" CONFIG_FILE, get_home_directory ());
+  return config_filename;
+}
+
+char *get_downloads_directory (void)
+{
+  char *downloads_directory;
+  int length = strlen (get_config_directory ()) + strlen (DOWNLOADS_DIRECTORY) + 2;
+
+  downloads_directory = (char *) calloc (length, sizeof (char));
+  sprintf (downloads_directory, "%s/" DOWNLOADS_DIRECTORY, get_config_directory ());
+
+  return downloads_directory;
+}
+
+void running_for_first_time (void) {
+  struct stat *config_file_stat = NULL;
+  int config_file_fd;
+  char *config_directory = get_config_directory ();
+  char *config_filename = get_config_filename ();
+  char *downloads_directory = get_downloads_directory ();
+
+  if (mkdir (config_directory, CONFIG_DIRECTORY_MODE) != 0) {
+    return;
+  } else {
+    printf ("\nRunning " PROGNAME " for first time!!\n");
+    printf ("[%s] created\n", config_directory);
+  }
+
+  // see if config file is there
+  if (stat (config_filename, config_file_stat) != 0) {
+    // config file missing, so touch it
+    config_file_fd = open (config_filename, O_CREAT | O_RDWR, S_IRWXU);
+    if (config_file_fd == -1)	{
+  	  perror ("open[config_file]");
+	    exit (EXIT_FAILURE);
+  	}
+    if (fchmod (config_file_fd, CONFIG_DIRECTORY_MODE) != 0) {
+  	  perror ("fchmod[" CONFIG_FILE "]");
+	    exit (EXIT_FAILURE);
+  	}
+    if (write (config_file_fd, DEFAULT_CONFIG_CONTENTS, strlen (DEFAULT_CONFIG_CONTENTS)) <= 0) {
+  	  perror ("write[config_file]");
+	    exit (EXIT_FAILURE);
+  	}
+    close (config_file_fd);
+    printf ("[%s] created\n", config_filename);
+  
+    /* create downloads directory */
+    if (mkdir (downloads_directory, 0755) !=0) {
+	    perror ("creating download directory");
+	    exit (EXIT_FAILURE);
+  	}
+  }
+
+  set_setup_mode ();
+}
+
+void inner_main (void) {
+  loop ();
+}
+
+void usage (void) {
+  printf ("%s [-u username]\n", PROGNAME);
+  exit (1);
+}
+
+void args_parse (int argc, char **argv) {
+  int opt = 0;
+  while ((opt = getopt (argc, argv, "u:h")) != -1) {
+    switch (opt) {
+    case 'u':
+      set_default_username (optarg);
+      break;
+    case 'h':
+    default:
+      usage ();
+      break;
+    }
+  }
+}
+
+int main (int argc, char **argv) {
+  running_for_first_time ();
+
+  get_terminal_attributes ();
+
+  args_parse (argc, argv);
+
+  inner_main ();
+  
+  return 0;
+}