cmdedit.c

shell-HHARM9200.rar 华恒 AT91rm9200 中Busybox shell的源代码

/* vi: set sw=4 ts=4: */
/*
 * Termios command line History and Editting.
 *
 * Copyright (c) 1986-2003 may safely be consumed by a BSD or GPL license.
 * Written by:   Vladimir Oleynik <[e-mail]>
 *
 * Used ideas:
 *      Adam Rogoyski    <[e-mail]>
 *      Dave Cinege      <[e-mail]>
 *      Jakub Jelinek (c) 1995
 *      Erik Andersen    <[e-mail]> (Majorly adjusted for busybox)
 *
 * This code is 'as is' with no warranty.
 *
 *
 */

/*
   Usage and Known bugs:
   Terminal key codes are not extensive, and more will probably
   need to be added. This version was created on Debian GNU/Linux 2.x.
   Delete, Backspace, Home, End, and the arrow keys were tested
   to work in an Xterm and console. Ctrl-A also works as Home.
   Ctrl-E also works as End.

   Small bugs (simple effect):
   - not true viewing if terminal size (x*y symbols) less
     size (prompt + editor`s line + 2 symbols)
   - not true viewing if length prompt less terminal width
 */


#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <ctype.h>
#include <signal.h>
#include <limits.h>

#include "busybox.h"

#include "../shell/cmdedit.h"


#ifdef CONFIG_LOCALE_SUPPORT
#define Isprint(c) isprint((c))
#else
#define Isprint(c) ( (c) >= ' ' && (c) != ((unsigned char)'\233') )
#endif

#ifdef TEST

/* pretect redefined for test */
#undef CONFIG_FEATURE_COMMAND_EDITING
#undef CONFIG_FEATURE_COMMAND_TAB_COMPLETION
#undef CONFIG_FEATURE_COMMAND_USERNAME_COMPLETION
#undef CONFIG_FEATURE_NONPRINTABLE_INVERSE_PUT
#undef CONFIG_FEATURE_CLEAN_UP

#define CONFIG_FEATURE_COMMAND_EDITING
#define CONFIG_FEATURE_COMMAND_TAB_COMPLETION
#define CONFIG_FEATURE_COMMAND_USERNAME_COMPLETION
#define CONFIG_FEATURE_NONPRINTABLE_INVERSE_PUT
#define CONFIG_FEATURE_CLEAN_UP

#endif                                                  /* TEST */

#ifdef CONFIG_FEATURE_COMMAND_TAB_COMPLETION
#include <dirent.h>
#include <sys/stat.h>
#endif

#ifdef CONFIG_FEATURE_COMMAND_EDITING

#if defined(CONFIG_FEATURE_COMMAND_USERNAME_COMPLETION) || defined(CONFIG_FEATURE_SH_FANCY_PROMPT)
#define CONFIG_FEATURE_GETUSERNAME_AND_HOMEDIR
#endif

#ifdef CONFIG_FEATURE_GETUSERNAME_AND_HOMEDIR
#include "pwd_.h"
#endif                                                  /* advanced FEATURES */


/* Maximum length of the linked list for the command line history */
#ifndef CONFIG_FEATURE_COMMAND_HISTORY
#define MAX_HISTORY   15
#else
#define MAX_HISTORY   CONFIG_FEATURE_COMMAND_HISTORY
#endif

#if MAX_HISTORY < 1
#warning cmdedit: You set MAX_HISTORY < 1. The history algorithm switched off.
#else
static char *history[MAX_HISTORY+1]; /* history + current */
/* saved history lines */
static int n_history;
/* current pointer to history line */
static int cur_history;
#endif

#include <termios.h>
#define setTermSettings(fd,argp) tcsetattr(fd,TCSANOW,argp)
#define getTermSettings(fd,argp) tcgetattr(fd, argp);

/* Current termio and the previous termio before starting sh */
static struct termios initial_settings, new_settings;


static
volatile int cmdedit_termw = 80;        /* actual terminal width */
static
volatile int handlers_sets = 0; /* Set next bites: */

enum {
	SET_ATEXIT = 1,         /* when atexit() has been called
				   and get euid,uid,gid to fast compare */
	SET_WCHG_HANDLERS = 2,  /* winchg signal handler */
	SET_RESET_TERM = 4,     /* if the terminal needs to be reset upon exit */
};


static int cmdedit_x;           /* real x terminal position */
static int cmdedit_y;           /* pseudoreal y terminal position */
static int cmdedit_prmt_len;    /* lenght prompt without colores string */

static int cursor;              /* required global for signal handler */
static int len;                 /* --- "" - - "" - -"- --""-- --""--- */
static char *command_ps;        /* --- "" - - "" - -"- --""-- --""--- */
static
#ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
	const
#endif
char *cmdedit_prompt;           /* --- "" - - "" - -"- --""-- --""--- */

#ifdef CONFIG_FEATURE_GETUSERNAME_AND_HOMEDIR
static char *user_buf = "";
static char *home_pwd_buf = "";
static int my_euid;
#endif

#ifdef CONFIG_FEATURE_SH_FANCY_PROMPT
static char *hostname_buf;
static int num_ok_lines = 1;
#endif


#ifdef  CONFIG_FEATURE_COMMAND_TAB_COMPLETION

#ifndef CONFIG_FEATURE_GETUSERNAME_AND_HOMEDIR
static int my_euid;
#endif

static int my_uid;
static int my_gid;

#endif  /* CONFIG_FEATURE_COMMAND_TAB_COMPLETION */

static void cmdedit_setwidth(int w, int redraw_flg);

static void win_changed(int nsig)
{
	static sighandler_t previous_SIGWINCH_handler;  /* for reset */

	/*   emulate      || signal call */
	if (nsig == -SIGWINCH || nsig == SIGWINCH) {
		int width = 0;
		get_terminal_width_height(0, &width, NULL);
		cmdedit_setwidth(width, nsig == SIGWINCH);
	}
	/* Unix not all standart in recall signal */

	if (nsig == -SIGWINCH)          /* save previous handler   */
		previous_SIGWINCH_handler = signal(SIGWINCH, win_changed);
	else if (nsig == SIGWINCH)      /* signaled called handler */
		signal(SIGWINCH, win_changed);  /* set for next call       */
	else                                            /* nsig == 0 */
		/* set previous handler    */
		signal(SIGWINCH, previous_SIGWINCH_handler);    /* reset    */
}

static void cmdedit_reset_term(void)
{
	if ((handlers_sets & SET_RESET_TERM) != 0) {
/* sparc and other have broken termios support: use old termio handling. */
		setTermSettings(STDIN_FILENO, (void *) &initial_settings);
		handlers_sets &= ~SET_RESET_TERM;
	}
	if ((handlers_sets & SET_WCHG_HANDLERS) != 0) {
		/* reset SIGWINCH handler to previous (default) */
		win_changed(0);
		handlers_sets &= ~SET_WCHG_HANDLERS;
	}
	fflush(stdout);
}


/* special for recount position for scroll and remove terminal margin effect */
static void cmdedit_set_out_char(int next_char)
{

	int c = (int)((unsigned char) command_ps[cursor]);

	if (c == 0)
		c = ' ';        /* destroy end char? */
#ifdef CONFIG_FEATURE_NONPRINTABLE_INVERSE_PUT
	if (!Isprint(c)) {      /* Inverse put non-printable characters */
		if (c >= 128)
			c -= 128;
		if (c < ' ')
			c += '@';
		if (c == 127)
			c = '?';
		printf("\033[7m%c\033[0m", c);
	} else
#endif
		putchar(c);
	if (++cmdedit_x >= cmdedit_termw) {
		/* terminal is scrolled down */
		cmdedit_y++;
		cmdedit_x = 0;

		if (!next_char)
			next_char = ' ';
		/* destroy "(auto)margin" */
		putchar(next_char);
		putchar('\b');
	}
	cursor++;
}

/* Move to end line. Bonus: rewrite line from cursor */
static void input_end(void)
{
	while (cursor < len)
		cmdedit_set_out_char(0);
}

/* Go to the next line */
static void goto_new_line(void)
{
	input_end();
	if (cmdedit_x)
		putchar('\n');
}


static inline void out1str(const char *s)
{
	if ( s )
		fputs(s, stdout);
}

static inline void beep(void)
{
	putchar('\007');
}

/* Move back one charactor */
/* special for slow terminal */
static void input_backward(int num)
{
	if (num > cursor)
		num = cursor;
	cursor -= num;          /* new cursor (in command, not terminal) */

	if (cmdedit_x >= num) {         /* no to up line */
		cmdedit_x -= num;
		if (num < 4)
			while (num-- > 0)
				putchar('\b');

		else
			printf("\033[%dD", num);
	} else {
		int count_y;

		if (cmdedit_x) {
			putchar('\r');          /* back to first terminal pos.  */
			num -= cmdedit_x;       /* set previous backward        */
		}
		count_y = 1 + num / cmdedit_termw;
		printf("\033[%dA", count_y);
		cmdedit_y -= count_y;
		/*  require  forward  after  uping   */
		cmdedit_x = cmdedit_termw * count_y - num;
		printf("\033[%dC", cmdedit_x);  /* set term cursor   */
	}
}

static void put_prompt(void)
{
	out1str(cmdedit_prompt);
	cmdedit_x = cmdedit_prmt_len;   /* count real x terminal position */
	cursor = 0;
	cmdedit_y = 0;                  /* new quasireal y */
}

#ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
static void parse_prompt(const char *prmt_ptr)
{
	cmdedit_prompt = prmt_ptr;
	cmdedit_prmt_len = strlen(prmt_ptr);
	put_prompt();
}
#else
static void parse_prompt(const char *prmt_ptr)
{
	int prmt_len = 0;
	int sub_len = 0;
	char  flg_not_length = '[';
	char *prmt_mem_ptr = xcalloc(1, 1);
	char *pwd_buf = xgetcwd(0);
	char  buf2[PATH_MAX + 1];
	char  buf[2];
	char  c;
	char *pbuf;

	if (!pwd_buf) {
		pwd_buf=(char *)bb_msg_unknown;
	}

	while (*prmt_ptr) {
		pbuf    = buf;
		pbuf[1] = 0;
		c = *prmt_ptr++;
		if (c == '\\') {
			const char *cp = prmt_ptr;
			int l;

			c = bb_process_escape_sequence(&prmt_ptr);
			if(prmt_ptr==cp) {
			  if (*cp == 0)
				break;
			  c = *prmt_ptr++;
			  switch (c) {
#ifdef CONFIG_FEATURE_GETUSERNAME_AND_HOMEDIR
			  case 'u':
				pbuf = user_buf;
				break;
#endif
			  case 'h':
				pbuf = hostname_buf;
				if (pbuf == 0) {
					pbuf = xcalloc(256, 1);
					if (gethostname(pbuf, 255) < 0) {
						strcpy(pbuf, "?");
					} else {
						char *s = strchr(pbuf, '.');

						if (s)
							*s = 0;
					}
					hostname_buf = pbuf;
				}
				break;
			  case '$':
				c = my_euid == 0 ? '#' : '$';
				break;
#ifdef CONFIG_FEATURE_GETUSERNAME_AND_HOMEDIR
			  case 'w':
				pbuf = pwd_buf;
				l = strlen(home_pwd_buf);
				if (home_pwd_buf[0] != 0 &&
				    strncmp(home_pwd_buf, pbuf, l) == 0 &&
				    (pbuf[l]=='/' || pbuf[l]=='\0') &&
				    strlen(pwd_buf+l)<PATH_MAX) {
					pbuf = buf2;
					*pbuf = '~';
					strcpy(pbuf+1, pwd_buf+l);
					}
				break;
#endif
			  case 'W':
				pbuf = pwd_buf;
				cp = strrchr(pbuf,'/');
				if ( (cp != NULL) && (cp != pbuf) )
					pbuf += (cp-pbuf)+1;
				break;
			  case '!':
				snprintf(pbuf = buf2, sizeof(buf2), "%d", num_ok_lines);
				break;
			  case 'e': case 'E':     /* \e \E = \033 */
				c = '\033';
				break;
			  case 'x': case 'X':
				for (l = 0; l < 3;) {
					int h;
					buf2[l++] = *prmt_ptr;
					buf2[l] = 0;
					h = strtol(buf2, &pbuf, 16);
					if (h > UCHAR_MAX || (pbuf - buf2) < l) {
						l--;
						break;
					}
					prmt_ptr++;
				}
				buf2[l] = 0;
				c = (char)strtol(buf2, 0, 16);
				if(c==0)
					c = '?';
				pbuf = buf;
				break;
			  case '[': case ']':
				if (c == flg_not_length) {
					flg_not_length = flg_not_length == '[' ? ']' : '[';
					continue;
				}
				break;
			  }
			}
		}
		if(pbuf == buf)
			*pbuf = c;
		prmt_len += strlen(pbuf);
		prmt_mem_ptr = strcat(xrealloc(prmt_mem_ptr, prmt_len+1), pbuf);
		if (flg_not_length == ']')
			sub_len++;
	}
	if(pwd_buf!=(char *)bb_msg_unknown)
		free(pwd_buf);
	cmdedit_prompt = prmt_mem_ptr;
	cmdedit_prmt_len = prmt_len - sub_len;
	put_prompt();
}
#endif


/* draw promt, editor line, and clear tail */
static void redraw(int y, int back_cursor)
{
	if (y > 0)                              /* up to start y */
		printf("\033[%dA", y);
	putchar('\r');
	put_prompt();
	input_end();                            /* rewrite */
	printf("\033[J");                       /* destroy tail after cursor */
	input_backward(back_cursor);
}

/* Delete the char in front of the cursor */
static void input_delete(void)
{
	int j = cursor;

	if (j == len)
		return;

	strcpy(command_ps + j, command_ps + j + 1);
	len--;
	input_end();                    /* rewtite new line */
	cmdedit_set_out_char(0);        /* destroy end char */
	input_backward(cursor - j);     /* back to old pos cursor */
}

/* Delete the char in back of the cursor */
static void input_backspace(void)
{
	if (cursor > 0) {
		input_backward(1);
		input_delete();
	}
}


/* Move forward one charactor */
static void input_forward(void)
{
	if (cursor < len)
		cmdedit_set_out_char(command_ps[cursor + 1]);
}


static void cmdedit_setwidth(int w, int redraw_flg)
{
	cmdedit_termw = cmdedit_prmt_len + 2;
	if (w <= cmdedit_termw) {
		cmdedit_termw = cmdedit_termw % w;
	}
	if (w > cmdedit_termw) {
		cmdedit_termw = w;

		if (redraw_flg) {
			/* new y for current cursor */
			int new_y = (cursor + cmdedit_prmt_len) / w;

			/* redraw */
			redraw((new_y >= cmdedit_y ? new_y : cmdedit_y), len - cursor);
			fflush(stdout);
		}
	}
}

static void cmdedit_init(void)
{
	cmdedit_prmt_len = 0;
	if ((handlers_sets & SET_WCHG_HANDLERS) == 0) {
		/* emulate usage handler to set handler and call yours work */
		win_changed(-SIGWINCH);
		handlers_sets |= SET_WCHG_HANDLERS;
	}

	if ((handlers_sets & SET_ATEXIT) == 0) {
#ifdef CONFIG_FEATURE_GETUSERNAME_AND_HOMEDIR
		struct passwd *entry;

		my_euid = geteuid();
		entry = getpwuid(my_euid);
		if (entry) {
			user_buf = bb_xstrdup(entry->pw_name);
			home_pwd_buf = bb_xstrdup(entry->pw_dir);
		}
#endif

#ifdef  CONFIG_FEATURE_COMMAND_TAB_COMPLETION

#ifndef CONFIG_FEATURE_GETUSERNAME_AND_HOMEDIR
		my_euid = geteuid();
#endif
		my_uid = getuid();
		my_gid = getgid();
#endif  /* CONFIG_FEATURE_COMMAND_TAB_COMPLETION */
		handlers_sets |= SET_ATEXIT;
		atexit(cmdedit_reset_term);     /* be sure to do this only once */
	}