/* * Copyright (c) 1993-1994 by Xerox Corporation. All rights reserved. * * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. * * Permission is hereby granted to use or copy this program * for any purpose, provided the above notices are retained on all copies. * Permission to modify the code and to distribute modified code is granted, * provided the above notices are retained, and a notice that the code was * modified is included with the above copyright notice. * * Author: Hans-J. Boehm (boehm@parc.xerox.com) */ /* * A really simple-minded text editor based on cords. * Things it does right: * No size bounds. * Inbounded undo. * Shouldn't crash no matter what file you invoke it on (e.g. /vmunix) * (Make sure /vmunix is not writable before you try this.) * Scrolls horizontally. * Things it does wrong: * It doesn't handle tabs reasonably (use "expand" first). * The command set is MUCH too small. * The redisplay algorithm doesn't let curses do the scrolling. * The rule for moving the window over the file is suboptimal. */ /* Boehm, February 6, 1995 12:27 pm PST */ /* Boehm, May 19, 1994 2:20 pm PDT */ #include <stdio.h> #include "gc.h" #include "cord.h" #ifdef THINK_C #define MACINTOSH #include <ctype.h> #endif #if defined(__BORLANDC__) && !defined(WIN32) /* If this is DOS or win16, we'll fail anyway. */ /* Might as well assume win32. */ # define WIN32 #endif #if defined(WIN32) # include <windows.h> # include "de_win.h" #elif defined(MACINTOSH) # include <console.h> /* curses emulation. */ # define initscr() # define endwin() # define nonl() # define noecho() csetmode(C_NOECHO, stdout) # define cbreak() csetmode(C_CBREAK, stdout) # define refresh() # define addch(c) putchar(c) # define standout() cinverse(1, stdout) # define standend() cinverse(0, stdout) # define move(line,col) cgotoxy(col + 1, line + 1, stdout) # define clrtoeol() ccleol(stdout) # define de_error(s) { fprintf(stderr, s); getchar(); } # define LINES 25 # define COLS 80 #else # include <curses.h> # define de_error(s) { fprintf(stderr, s); sleep(2); } #endif #include "de_cmds.h" /* List of line number to position mappings, in descending order. */ /* There may be holes. */ typedef struct LineMapRep { int line; size_t pos; struct LineMapRep * previous; } * line_map; /* List of file versions, one per edit operation */ typedef struct HistoryRep { CORD file_contents; struct HistoryRep * previous; line_map map; /* Invalid for first record "now" */ } * history; history now = 0; CORD current; /* == now -> file_contents. */ size_t current_len; /* Current file length. */ line_map current_map = 0; /* Current line no. to pos. map */ size_t current_map_size = 0; /* Number of current_map entries. */ /* Not always accurate, but reset */ /* by prune_map. */ # define MAX_MAP_SIZE 3000 /* Current display position */ int dis_line = 0; int dis_col = 0; # define ALL -1 # define NONE - 2 int need_redisplay = 0; /* Line that needs to be redisplayed. */ /* Current cursor position. Always within file. */ int line = 0; int col = 0; size_t file_pos = 0; /* Character position corresponding to cursor. */ /* Invalidate line map for lines > i */ void invalidate_map(int i) { while(current_map -> line > i) { current_map = current_map -> previous; current_map_size--; } } /* Reduce the number of map entries to save space for huge files. */ /* This also affects maps in histories. */ void prune_map() { line_map map = current_map; int start_line = map -> line; current_map_size = 0; for(; map != 0; map = map -> previous) { current_map_size++; if (map -> line < start_line - LINES && map -> previous != 0) { map -> previous = map -> previous -> previous; } } } /* Add mapping entry */ void add_map(int line, size_t pos) { line_map new_map = GC_NEW(struct LineMapRep); if (current_map_size >= MAX_MAP_SIZE) prune_map(); new_map -> line = line; new_map -> pos = pos; new_map -> previous = current_map; current_map = new_map; current_map_size++; } /* Return position of column *c of ith line in */ /* current file. Adjust *c to be within the line.*/ /* A 0 pointer is taken as 0 column. */ /* Returns CORD_NOT_FOUND if i is too big. */ /* Assumes i > dis_line. */ size_t line_pos(int i, int *c) { int j; size_t cur; size_t next; line_map map = current_map; while (map -> line > i) map = map -> previous; if (map -> line < i - 2) /* rebuild */ invalidate_map(i); for (j = map -> line, cur = map -> pos; j < i;) { cur = CORD_chr(current, cur, '\n'); if (cur == current_len-1) return(CORD_NOT_FOUND); cur++; if (++j > current_map -> line) add_map(j, cur); } if (c != 0) { next = CORD_chr(current, cur, '\n'); if (next == CORD_NOT_FOUND) next = current_len - 1; if (next < cur + *c) { *c = next - cur; } cur += *c; } return(cur); } void add_hist(CORD s) { history new_file = GC_NEW(struct HistoryRep); new_file -> file_contents = current = s; current_len = CORD_len(s); new_file -> previous = now; if (now != 0) now -> map = current_map; now = new_file; } void del_hist(void) { now = now -> previous; current = now -> file_contents; current_map = now -> map; current_len = CORD_len(current); } /* Current screen_contents; a dynamically allocated array of CORDs */ CORD * screen = 0; int screen_size = 0; # ifndef WIN32 /* Replace a line in the curses stdscr. All control characters are */ /* displayed as upper case characters in standout mode. This isn't */ /* terribly appropriate for tabs. */ void replace_line(int i, CORD s) { register int c; CORD_pos p; size_t len = CORD_len(s); if (screen == 0 || LINES > screen_size) { screen_size = LINES; screen = (CORD *)GC_MALLOC(screen_size * sizeof(CORD)); } # if !defined(MACINTOSH) /* A gross workaround for an apparent curses bug: */ if (i == LINES-1 && len == COLS) { s = CORD_substr(s, 0, CORD_len(s) - 1); } # endif if (CORD_cmp(screen[i], s) != 0) { move(i, 0); clrtoeol(); move(i,0); CORD_FOR (p, s) { c = CORD_pos_fetch(p) & 0x7f; if (iscntrl(c)) { standout(); addch(c + 0x40); standend(); } else { addch(c); } } screen[i] = s; } } #else # define replace_line(i,s) invalidate_line(i) #endif /* Return up to COLS characters of the line of s starting at pos, */ /* returning only characters after the given column. */ CORD retrieve_line(CORD s, size_t pos, unsigned column) { CORD candidate = CORD_substr(s, pos, column + COLS); /* avoids scanning very long lines */ int eol = CORD_chr(candidate, 0, '\n'); int len; if (eol == CORD_NOT_FOUND) eol = CORD_len(candidate); len = (int)eol - (int)column; if (len < 0) len = 0; return(CORD_substr(s, pos + column, len)); } # ifdef WIN32 # define refresh(); CORD retrieve_screen_line(int i) { register size_t pos; invalidate_map(dis_line + LINES); /* Prune search */ pos = line_pos(dis_line + i, 0); if (pos == CORD_NOT_FOUND) return(CORD_EMPTY); return(retrieve_line(current, pos, dis_col)); } # endif /* Display the visible section of the current file */ void redisplay(void) { register int i; invalidate_map(dis_line + LINES); /* Prune search */ for (i = 0; i < LINES; i++) { if (need_redisplay == ALL || need_redisplay == i) { register size_t pos = line_pos(dis_line + i, 0); if (pos == CORD_NOT_FOUND) break; replace_line(i, retrieve_line(current, pos, dis_col)); if (need_redisplay == i) goto done; } } for (; i < LINES; i++) replace_line(i, CORD_EMPTY); done: refresh(); need_redisplay = NONE; } int dis_granularity; /* Update dis_line, dis_col, and dis_pos to make cursor visible. */ /* Assumes line, col, dis_line, dis_pos are in bounds. */ void normalize_display() { int old_line = dis_line; int old_col = dis_col; dis_granularity = 1; if (LINES > 15 && COLS > 15) dis_granularity = 2; while (dis_line > line) dis_line -= dis_granularity; while (dis_col > col) dis_col -= dis_granularity; while (line >= dis_line + LINES) dis_line += dis_granularity; while (col >= dis_col + COLS) dis_col += dis_granularity; if (old_line != dis_line || old_col != dis_col) { need_redisplay = ALL; } } # if defined(WIN32) # elif defined(MACINTOSH) # define move_cursor(x,y) cgotoxy(x + 1, y + 1, stdout) # else # define move_cursor(x,y) move(y,x) # endif /* Adjust display so that cursor is visible; move cursor into position */ /* Update screen if necessary. */ void fix_cursor(void) { normalize_display(); if (need_redisplay != NONE) redisplay(); move_cursor(col - dis_col, line - dis_line); refresh(); # ifndef WIN32 fflush(stdout); # endif } /* Make sure line, col, and dis_pos are somewhere inside file. */ /* Recompute file_pos. Assumes dis_pos is accurate or past eof */ void fix_pos() { int my_col = col; if ((size_t)line > current_len) line = current_len; file_pos = line_pos(line, &my_col); if (file_pos == CORD_NOT_FOUND) { for (line = current_map -> line, file_pos = current_map -> pos; file_pos < current_len; line++, file_pos = CORD_chr(current, file_pos, '\n') + 1); line--; file_pos = line_pos(line, &col); } else { col = my_col; } } #if defined(WIN32) # define beep() Beep(1000 /* Hz */, 300 /* msecs */) #elif defined(MACINTOSH) # define beep() SysBeep(1) #else /* * beep() is part of some curses packages and not others. * We try to match the type of the builtin one, if any. */ #ifdef __STDC__ int beep(void) #else int beep() #endif { putc('\007', stderr); return(0); } #endif # define NO_PREFIX -1 # define BARE_PREFIX -2 int repeat_count = NO_PREFIX; /* Current command prefix. */ int locate_mode = 0; /* Currently between 2 ^Ls */ CORD locate_string = CORD_EMPTY; /* Current search string. */ char * arg_file_name; #ifdef WIN32 /* Change the current position to whatever is currently displayed at */ /* the given SCREEN coordinates. */ void set_position(int c, int l) { line = l + dis_line; col = c + dis_col; fix_pos(); move_cursor(col - dis_col, line - dis_line); } #endif /* WIN32 */ /* Perform the command associated with character c. C may be an */ /* integer > 256 denoting a windows command, one of the above control */ /* characters, or another ASCII character to be used as either a */ /* character to be inserted, a repeat count, or a search string, */ /* depending on the current state. */ void do_command(int c) { int i; int need_fix_pos; FILE * out; if ( c == '\r') c = '\n'; if (locate_mode) { size_t new_pos; if (c == LOCATE) { locate_mode = 0; locate_string = CORD_EMPTY; return; } locate_string = CORD_cat_char(locate_string, (char)c); new_pos = CORD_str(current, file_pos - CORD_len(locate_string) + 1, locate_string); if (new_pos != CORD_NOT_FOUND) { need_redisplay = ALL; new_pos += CORD_len(locate_string); for (;;) { file_pos = line_pos(line + 1, 0); if (file_pos > new_pos) break; line++; } col = new_pos - line_pos(line, 0); file_pos = new_pos; fix_cursor(); } else { locate_string = CORD_substr(locate_string, 0, CORD_len(locate_string) - 1); beep(); } return; } if (c == REPEAT) { repeat_count = BARE_PREFIX; return; } else if (c < 0x100 && isdigit(c)){ if (repeat_count == BARE_PREFIX) { repeat_count = c - '0'; return; } else if (repeat_count != NO_PREFIX) { repeat_count = 10 * repeat_count + c - '0'; return; } } if (repeat_count == NO_PREFIX) repeat_count = 1; if (repeat_count == BARE_PREFIX && (c == UP || c == DOWN)) { repeat_count = LINES - dis_granularity; } if (repeat_count == BARE_PREFIX) repeat_count = 8; need_fix_pos = 0; for (i = 0; i < repeat_count; i++) { switch(c) { case LOCATE: locate_mode = 1; break; case TOP: line = col = file_pos = 0; break; case UP: if (line != 0) { line--; need_fix_pos = 1; } break; case DOWN: line++; need_fix_pos = 1; break; case LEFT: if (col != 0) { col--; file_pos--; } break; case RIGHT: if (CORD_fetch(current, file_pos) == '\n') break; col++; file_pos++; break; case UNDO: del_hist(); need_redisplay = ALL; need_fix_pos = 1; break; case BS: if (col == 0) { beep(); break; } col--; file_pos--; /* fall through: */ case DEL: if (file_pos == current_len-1) break; /* Can't delete trailing newline */ if (CORD_fetch(current, file_pos) == '\n') { need_redisplay = ALL; need_fix_pos = 1; } else { need_redisplay = line - dis_line; } add_hist(CORD_cat( CORD_substr(current, 0, file_pos), CORD_substr(current, file_pos+1, current_len))); invalidate_map(line); break; case WRITE: { CORD name = CORD_cat(CORD_from_char_star(arg_file_name), ".new"); if ((out = fopen(CORD_to_const_char_star(name), "wb")) == NULL || CORD_put(current, out) == EOF) { de_error("Write failed\n"); need_redisplay = ALL; } else { fclose(out); } } break; default: { CORD left_part = CORD_substr(current, 0, file_pos); CORD right_part = CORD_substr(current, file_pos, current_len); add_hist(CORD_cat(CORD_cat_char(left_part, (char)c), right_part)); invalidate_map(line); if (c == '\n') { col = 0; line++; file_pos++; need_redisplay = ALL; } else { col++; file_pos++; need_redisplay = line - dis_line; } break; } } } if (need_fix_pos) fix_pos(); fix_cursor(); repeat_count = NO_PREFIX; } /* OS independent initialization */ void generic_init(void) { FILE * f; CORD initial; if ((f = fopen(arg_file_name, "rb")) == NULL) { initial = "\n"; } else { initial = CORD_from_file(f); if (initial == CORD_EMPTY || CORD_fetch(initial, CORD_len(initial)-1) != '\n') { initial = CORD_cat(initial, "\n"); } } add_map(0,0); add_hist(initial); now -> map = current_map; now -> previous = now; /* Can't back up further: beginning of the world */ need_redisplay = ALL; fix_cursor(); } #ifndef WIN32 main(argc, argv) int argc; char ** argv; { int c; #if defined(MACINTOSH) console_options.title = "\pDumb Editor"; cshow(stdout); GC_init(); argc = ccommand(&argv); #endif if (argc != 2) goto usage; arg_file_name = argv[1]; setvbuf(stdout, GC_MALLOC_ATOMIC(8192), _IOFBF, 8192); initscr(); noecho(); nonl(); cbreak(); generic_init(); while ((c = getchar()) != QUIT) { if (c == EOF) break; do_command(c); } done: move(LINES-1, 0); clrtoeol(); refresh(); nl(); echo(); endwin(); exit(0); usage: fprintf(stderr, "Usage: %s file\n", argv[0]); fprintf(stderr, "Cursor keys: ^B(left) ^F(right) ^P(up) ^N(down)\n"); fprintf(stderr, "Undo: ^U Write to <file>.new: ^W"); fprintf(stderr, "Quit:^D Repeat count: ^R[n]\n"); fprintf(stderr, "Top: ^T Locate (search, find): ^L text ^L\n"); exit(1); } #endif /* !WIN32 */