sted.c

sted 是一个非常小的简单的基于 ncurses的文本编辑器。而且如果你认为其他编辑器太乏味的话它还携带着一个幻觉模式选择

/***************************************************************************
 * sted 0.01 - Simple (and/or Stupid) Text Editor, by Linus Akerlund.
 *                e-mail: [e-mail]
 *                homepage: http://user.tninet.se/~uxm165t/index.htm
 *
 * (C) 1998 Linus Akerlund
 *
 * sted is a little program that lets you edit text files. It's supposed
 * to be small and simple. The code is also simple, but as I'm not very
 * much of a programmer, it may not be as small as it should be. You'll
 * find lots of strange things if you take a look at the code, because I'm
 * not very good at this (yet?). If you find something that could have been
 * done in a better (more economical, more efficient) way, please send me
 * an e-mail and tell me about it, or just fix it and send me a patch. I've
 * seen quite a few things in the code that I can improve a lot, and I'll 
 * probably get around to doing something about that, before I start
 * implementing functions that makes this resemble a real text editor.
 *
 *   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 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, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 **************************************************************************/


#include <curses.h>
#include <signal.h>
#include <string.h>
#include <stdlib.h>

#define LINE_LENGTH 255		/* Maximum length of a line. */
#define TAB_SPACING 5		/* Number of characters per tab. */

struct line
  {				/* The storage for the text. */
    char *content;
    int number;
    struct line *next;
  };

typedef struct line rad;	/* And a typedef, because I'm to lazy to type
				 * 'struct' all the time. */

static void finish (int sig);
void clean_up (void);
void push_numbers (int line_number);
void add_line (char *buffer, int line_number);
void modify_line (char *buffer, int line_number);
void del_line (int line_number);
char *get_line (int line_number);
void show_list (int top_line, int left_col, int y, int x);
int save_file (char *file_name);
int load_file (char *file_name, int *lines);

rad *head = NULL;		/* The head pointer for the linked list. */

/**************************************************************************
 * The main function
 * Returns: nothing (will change).
 * Arguments: the usual ones.
 *
 * Does some initializations and then starts waiting for input from the
 * user. Processes the input and stores it.
 **************************************************************************/

void
main (int argc, char *argv[])
{
  int count = 0, count2 = 0, count3 = 0, c, x = 0, y = 0;
  int line_number = 0, x_pos = 0, lines = 0, *lines_p = &lines; 
  int top_line = 0, left_col = 0;
  int save_err = 0, load_err = 0, colour = 2, colour_on = 0;
  char buffer[LINE_LENGTH + 1], temp_buffer[LINE_LENGTH + 1];
  char file_name[257];
  
  for (count = 0; count < LINE_LENGTH; count++)
    temp_buffer[count] = buffer[count] = '\0';
  for (count = 0; count < 256; count++)
    file_name[count] = '\0';

  (void) signal (SIGINT, finish); /* arrange interrupts to terminate */

  (void) initscr ();	  /* initialize the curses library */
  keypad (stdscr, TRUE);  /* enable keyboard mapping */
  (void) cbreak ();	  /* take input chars one at a time, no wait for NL */
  (void) noecho ();	  /* don't echo input */
  refresh ();		  /* to clear the screen */

    if (has_colors ())
    {
      start_color ();
      /*
       * simple colour assigment, often all we need.
       * This comes straight from the ncurses tutorial...
       * No colours are used in this program.
       */
      init_pair (COLOR_BLACK, COLOR_BLACK, COLOR_BLACK);
      init_pair (COLOR_GREEN, COLOR_GREEN, COLOR_BLACK);
      init_pair (COLOR_RED, COLOR_RED, COLOR_BLACK);
      init_pair (COLOR_CYAN, COLOR_CYAN, COLOR_BLACK);
      init_pair (COLOR_WHITE, COLOR_WHITE, COLOR_BLACK);
      init_pair (COLOR_MAGENTA, COLOR_MAGENTA, COLOR_BLACK);
      init_pair (COLOR_BLUE, COLOR_BLUE, COLOR_BLACK);
      init_pair (COLOR_YELLOW, COLOR_YELLOW, COLOR_BLACK);
    } 

  if (argc > 1)
    {
      for (count2 = 1; count2 < argc; count2++)
	{
	  if (argv[count2][0] == '-')
	    {
	      if (argv[count2][1] == 'p')
		colour_on = 1;
	      count = 1;
	    }
	  else
	    {
	      strcpy (file_name, argv[count2]);
	      load_err = load_file (file_name, lines_p);
	      if (load_err != 0)
		{
		  move (12, 0);
		  clrtoeol ();
		  addstr ("Could not open file ");
		  for (count = 0; count < (strlen (file_name)); count++)
		    addch (file_name[count]);
		  addstr (". Starting with empty buffer.");
		  refresh ();
		  getch ();
		}
	      else
		strcpy (buffer, get_line (0));
	    }
	  show_list (top_line, left_col, y, x);
	  refresh ();
	  move (0, 0);
	}
    }
/* This is the main loop, which lets you input characters, and processes
 * them in a more or less appropriate way. */
  
  while (1)
    {
      c = getch ();		/* accept single key as input */
      getsyx (y, x);		/* Get cursor coordinates */

      switch (c)
	{
	case 1 ... 8 :
	case 11 ... 30 : 
	case 32 ... 153 :		/* Most characters... */
	  if (strlen (buffer) == LINE_LENGTH - 1)
	    break;		/* Removed all the beeps. */
	  else
	    {
	      for (count = strlen (buffer) + 1; count > x_pos; count--)
		buffer[count] = buffer[count - 1];
	      buffer[x_pos++] = c;
	      if (x == COLS - 1) 
		{
		  ++left_col;
		}
  	      move (y, x_pos - left_col); 
	    }
	  break;
	case '\t' :
	  if (strlen(buffer) == (LINE_LENGTH - 1))
	    break;
	  else
	    {
	      for (count = strlen (buffer) + 1; count > x_pos; count--)
		buffer[count] = buffer[count - 1];
	      buffer[x_pos++] = '\t';
		for (count3 = 0; count3 < (TAB_SPACING - 1); count3++)
		  {
		    for (count2 = strlen (buffer) +1; count2 > x_pos; count2--)
		      buffer[count2] = buffer[count2 - 1];
		    buffer[x_pos++] = ' ';
		    if (left_col < (x_pos - COLS))
			left_col = x_pos - COLS;
		    move (y, x_pos - left_col);
		    if (((x_pos + count2) % TAB_SPACING) == 0)
		      break;
		  }
	    }
	  break;
	case '\n':		/* It's ugly, isn't it? Enter... */
	  for (count = x_pos; count < strlen (buffer); count++)
	    temp_buffer[count - x_pos] = buffer[count];
	  buffer[x_pos] = '\0';
	  move (y, 0);
	  push_numbers (line_number);
	  add_line (buffer, line_number);
	  for (count = 0; count < LINE_LENGTH; count++)
	    {
	      buffer[count] = temp_buffer[count];
	      temp_buffer[count] = '\0';
	    }
	  if (y == LINES - 1)
	    {
	      ++top_line;
	      move (y, 0);
	    }
	  else
	    move (++y, 0);
	  left_col = 0;
	  ++line_number;
	  ++lines;
	  x_pos = 0;
	  move(y, x_pos - left_col);
	  break;
	case KEY_BACKSPACE:	/* Backspace is not delete */
	  if (x_pos == 0 && line_number == 0)
	    break;              /* Removed all the beeps */
	  else if (x_pos == 0)
	    {
	      strcpy (temp_buffer, get_line (line_number - 1));
	      if (strlen (temp_buffer) + strlen (buffer) <
		  LINE_LENGTH)
		{
		  if (lines > line_number)
		    {
		      del_line (line_number);
		      --lines;
		    }
		  --line_number;
		  x_pos = strlen (temp_buffer);
		  left_col = x_pos - COLS - 1;
		  if (left_col < 0)
		    left_col = 0;
		  strcat (temp_buffer, buffer);
		  strcpy (buffer, temp_buffer);

		  if (y == 0)
		    {
		      --top_line;
		      move (y, 0);
		    }
		  else
		    move (--y, 0);
		  move (y, x_pos - left_col);
		  for (count = 0; count < LINE_LENGTH; count++)
		    temp_buffer[count] = '\0';
		}
	      else
		break;            /* Removed all the beeps. */
	    }
	  else
	    {
	      for (count = x_pos - 1; count < strlen (buffer); count++)
		buffer[count] = buffer[count + 1];
	      buffer[strlen (buffer) + 1] = '\0';
	      --x_pos;
	      if (x == 0)
		--left_col;
	      move (y, x_pos - left_col);
	    }
	  break;
	case KEY_DC:		/* Delete key, the way I want it to work */
	  if (x_pos == strlen (buffer))
	    {
	      if (line_number >= lines - 1)
		break;          /* Removed all the beeps. */
	      else
		{
		  strcpy (temp_buffer, get_line (line_number + 1));
		  if (strlen (temp_buffer) + strlen (buffer) <
		      LINE_LENGTH)
		    {
		      del_line (line_number + 1);
		      --lines;
		      strcat (buffer, temp_buffer);
		      move (y, x_pos - left_col);
		      for (count = 0; count < LINE_LENGTH; count++)
			temp_buffer[count] = '\0';
		    }
		  else
		    break;       /* Removed all the beeps. */
		}
	    }
	  else
	    {
	      for (count = x_pos; count < strlen (buffer); count++)
		buffer[count] = buffer[count + 1];
	      buffer[strlen (buffer) + 1] = '\0';
	      move (y, x_pos - left_col);
	    }
	  break;
	case KEY_LEFT:		/* Cursor left. */
	  if (x == 0)
	    {
	      if ((line_number == 0) && (left_col == 0))
		break;               /* Removed all the beeps. */
	      else if (left_col > 0)
		{
		  --left_col;
		  --x_pos;
		}
	      else
		{
		  if (line_number == lines)
		    {
		      add_line (buffer, line_number);
		      ++lines;
		    }
		  else
		    modify_line (buffer, line_number);
		  strcpy (buffer, get_line (--line_number));
		  if (buffer == NULL)
		    {
		      fprintf (stderr, "Couldn't get any line!");
		      exit (1);
		    }
		  if (y == 0)
		    {
		      --top_line;
		      move (y, 0);
		    }
		  else
		    move (--y, 0);
		  x_pos = strlen (buffer);
		  left_col = x_pos - (COLS - 1);
		  if (left_col < 0)
		    left_col = 0;
		  move (y, x_pos - left_col);
		}
	    }
	  else
	    move (y, (--x_pos) - left_col);
	  break;
	case KEY_RIGHT:	/* Cursor right. */
	  if (x_pos == strlen(buffer))
	    {
	      if (line_number >= lines - 1)
		break;             /* Removed all the beeps. */
	      else
		{
		  modify_line (buffer, line_number);
		  strcpy (buffer, get_line (++line_number));
		  if (buffer == NULL)
		    {
		      fprintf (stderr, "Couldn't get any line!");
		      exit (1);
		    }
		  if (y == LINES - 1)
		    {
		      ++top_line;
		      move (y, 0);
		    }
		  else
		    move (++y, 0);
		  x_pos = 0;
		  left_col = 0;
		  move (y, x_pos - left_col);
		}
	    }
	  else if (x == (COLS - 1))
	    {
	      ++x_pos;
	      ++left_col; 
	      move(y, x_pos - left_col);
	    }
	  else
	    move (y, (++x_pos) - left_col);
	  break;
	case KEY_HOME:		/* Home: to beginning of line. */
	  x_pos = 0;
	  left_col = 0;
	  break;
	case KEY_END:		/* End: to end of line. */
	  x_pos = strlen(buffer);
	  if ((x_pos) > (left_col + (COLS - 1)))
	    left_col = x_pos - (COLS - 1);
	  break;
	case KEY_UP:		/* Cursor up. */
	  if (line_number == 0)
	    break;              /* Removed all the beeps. */
	  else
	    {
	      if (line_number == lines)
		{
		  add_line (buffer, line_number);
		  ++lines;
		}
	      else
		modify_line (buffer, line_number);
	      strcpy (buffer, get_line (--line_number));
	      if (buffer == NULL)
		{
		  fprintf (stderr, "Couldn't get any line!");
		  exit (1);
		}
	      if (y == 0)
		{
		  --top_line;
		  move (y, 0);
		}
	      else
		move (--y, 0);
	      if (x_pos > strlen (buffer))
		x_pos = strlen (buffer);
	      if (x_pos < left_col)
		left_col = x_pos;
	      move (y, x_pos - left_col);
	    }
	  show_list (top_line, left_col, y, x);
	  break;
	case KEY_DOWN:		/* Cursor down. */
	  if (line_number >= lines - 1)
	    break;              /* Removed all the beeps. */
	  else
	    {
	      modify_line (buffer, line_number);
	      strcpy (buffer, get_line (++line_number));
	      if (buffer == NULL)
		{
		  fprintf (stderr, "Couldn't get any line!");
		  exit (1);
		}
	      if (y == LINES - 1)
		{
		  ++top_line;
		  move (y, 0);
		}
	      else
		move (++y, 0);
	      if (x_pos > strlen (buffer))
		x_pos = strlen (buffer);
	      if (x_pos < left_col)
		left_col = x_pos;
	      move (y, x_pos - left_col);
	    }
	  show_list (top_line, left_col, y, x);
	  break;
	case (KEY_NPAGE):
	  if (line_number >= lines - 1)
	    break;		/* Removed all the beeps. */
	  else
	    {
	      modify_line (buffer, line_number);
	      if (y == LINES - 1)
		{
		  line_number += (LINES - 1);
		  if (line_number >= lines)
		    line_number = lines - 1;
		  top_line = line_number - (LINES - 1);
		  y = lines - top_line - 1;
		}
	      else
		{
		  y = LINES - 1;
		  line_number = top_line + (LINES - 1);
		  if (line_number >= lines)
		    {
		      line_number = lines - 1;
		      y = lines - top_line - 1;
		    }
		}
	      strcpy (buffer, get_line (line_number));
	      if (x_pos > strlen (buffer))
		x_pos = strlen (buffer);
	      left_col = x_pos - (COLS - 1);
	      if (left_col < 0)
		left_col = 0;
	      show_list (top_line, left_col, y, x);
	    }
	  break;
	case (KEY_PPAGE):
	  if (line_number == 0)
	    break;		/* Removed all the beeps. */
	  else
	    {
	      if (line_number >= lines)
		{
		  add_line (buffer, line_number);
		  ++lines;
		}
	      else
		modify_line (buffer, line_number);
	      if (y == 0)
		{
		  line_number -= (LINES - 1);
		  if (line_number < 0)
		    line_number = 0;
		  top_line = line_number;
		  y = 0;
		}
	      else
		{
		  y = 0;
		  line_number = top_line;
		  if (line_number < 0)
		    {
		      line_number = 0;
		      y = 0;
		    }
		}
	      strcpy (buffer, get_line (line_number));
	      if (x_pos > strlen (buffer))
		x_pos = strlen (buffer);
	      left_col = x_pos - (COLS - 1);
	      if (left_col < 0)
		left_col = 0;
	      show_list (top_line, left_col, y, x);
	    }
	  break;
	case (KEY_F0 + 1):	/* F1 key exits */
	  move (11, 0);
	  clrtoeol ();
	  move (13, 0);
	  clrtoeol ();
	  move (12, 0);
	  clrtoeol ();
	  addstr ("Do you really want to quit? (Y/N)");
	  refresh ();
	  c = getch ();
	  if (c == 'y' || c == 'Y')
	    finish (0);
	  move (y, x_pos - left_col);
	  show_list (top_line, left_col, y, x);
	  break;
	case (KEY_F0 + 12):	/* F12 saves the file */
	  save_err = 0;
	  if (line_number >= lines)
	    {
	      add_line (buffer, line_number);
	      ++lines;
	    }
	  else
	    modify_line (buffer, line_number);
	  move (11, 0);
	  clrtoeol ();
	  move (13, 0);
	  clrtoeol ();
	  move (12, 0);
	  clrtoeol ();
	  while (strlen (file_name))
	    {
	      addstr ("Save as ");
	      for (count = 0; count < strlen (file_name); count++)
		addch (file_name[count]);
	      addstr ("? (Y/N)");
	      refresh ();
	      c = getch ();
	      if (c == 'y' || c == 'Y')
		{