more.c

Util-linux 软件包包含许多工具。其中比较重要的是加载、卸载、格式化、分区和管理硬盘驱动器

    else
	putcerr('\n');
    _exit(0);
}

void copy_file(register FILE *f) {
    register int c;

    while ((c = getc(f)) != EOF)
	putchar(c);
}

#define ringbell()	putcerr('\007')

/* See whether the last component of the path name "path" is equal to the
** string "string"
*/

static int tailequ (char *path, register char *string)
{
	register char *tail;

	tail = path + strlen(path);
	while (--tail >= path)
		if (*tail == '/')
			break;
	++tail;
	while (*tail++ == *string++)
		if (*tail == '\0')
			return(1);
	return(0);
}

static void prompt (char *filename)
{
    if (clreol)
	cleareol ();
    else if (promptlen > 0)
	kill_line ();
    if (!hard) {
	promptlen = 0;
	if (Senter && Sexit) {
	    my_putstring (Senter);
	    promptlen += (2 * soglitch);
	}
	if (clreol)
	    cleareol ();
	promptlen += printf(_("--More--"));
	if (filename != NULL) {
	    promptlen += printf(_("(Next file: %s)"), filename);
	} else if (!no_intty) {
	    promptlen += printf("(%d%%)", (int) ((file_pos * 100) / file_size));
	}
	if (dum_opt) {
	    promptlen += printf(_("[Press space to continue, 'q' to quit.]"));
	}
	if (Senter && Sexit)
	    my_putstring (Sexit);
	if (clreol)
	    clreos ();
	fflush(stdout);
    }
    else
	ringbell();
    inwait++;
}

/*
 * Get a logical line
 */

int get_line(register FILE *f, int *length)
{
    int	c;
    char *p;
    int	column;
    static int colflg;

#ifdef ENABLE_WIDECHAR
    int i;
    wchar_t wc;
    int wc_width;
    mbstate_t state, state_bak;		/* Current status of the stream. */
    unsigned char mbc[MB_LEN_MAX];	/* Buffer for one multibyte char. */
    size_t mblength;			/* Byte length of multibyte char. */
    size_t mbc_pos = 0;			/* Postion of the MBC. */
    int use_mbc_buffer_flag = 0;	/* If 1, mbc has data. */
    int break_flag = 0;			/* If 1, exit while(). */
    long file_pos_bak = Ftell (f);

    memset (&state, '\0', sizeof (mbstate_t));
#endif

    p = Line;
    column = 0;
    c = Getc (f);
    if (colflg && c == '\n') {
	Currline++;
	c = Getc (f);
    }
    while (p < &Line[LINSIZ - 1]) {
#ifdef ENABLE_WIDECHAR
	if (fold_opt && use_mbc_buffer_flag && MB_CUR_MAX > 1) {
	    use_mbc_buffer_flag = 0;
	    state_bak = state;
	    mbc[mbc_pos++] = c;
process_mbc:
	    mblength = mbrtowc (&wc, mbc, mbc_pos, &state);

	    switch (mblength) {
	      case (size_t)-2:	  /* Incomplete multibyte character. */
		use_mbc_buffer_flag = 1;
		state = state_bak;
		break;

	      case (size_t)-1:	  /* Invalid as a multibyte character. */
		*p++ = mbc[0];
		state = state_bak;
		column++;
		file_pos_bak++;
		
		if (column >= Mcol) {
		    Fseek (f, file_pos_bak);
		} else {
		    memmove (mbc, mbc + 1, --mbc_pos);
		    if (mbc_pos > 0) {
			mbc[mbc_pos] = '\0';
			goto process_mbc;
		    }
		}
		break;

	      default:
		wc_width = wcwidth (wc);

		if (column + wc_width > Mcol) {
		    Fseek (f, file_pos_bak);
		    break_flag = 1;
		} else {
		    for (i = 0; i < mbc_pos; i++)
		      *p++ = mbc[i];
		    if (wc_width > 0)
		      column += wc_width;
		}
	    }

	    if (break_flag || column >= Mcol)
	      break;

	    c = Getc (f);
	    continue;
	}
#endif 
	if (c == EOF) {
	    if (p > Line) {
		*p = '\0';
		*length = p - Line;
		return (column);
	    }
	    *length = p - Line;
	    return (EOF);
	}
	if (c == '\n') {
	    Currline++;
	    break;
	}

	*p++ = c;
#if 0
	if (c == '\033') {      /* ESC */
		c = Getc(f);
		while (c > ' ' && c < '0' && p < &Line[LINSIZ - 1]) {
			*p++ = c;
			c = Getc(f);
		}
		if (c >= '0' && c < '\177' && p < &Line[LINSIZ - 1]) {
			*p++ = c;
			c = Getc(f);
			continue;
		}
	}
#endif
	if (c == '\t') {
	    if (!hardtabs || (column < promptlen && !hard)) {
		if (hardtabs && eraseln && !dumb) {
		    column = 1 + (column | 7);
		    my_putstring (eraseln);
		    promptlen = 0;
		}
		else {
		    for (--p; p < &Line[LINSIZ - 1];) {
			*p++ = ' ';
			if ((++column & 7) == 0)
			    break;
		    }
		    if (column >= promptlen) promptlen = 0;
		}
	    } else
		column = 1 + (column | 7);
	} else if (c == '\b' && column > 0) {
	    column--;
	} else if (c == '\r') {
	    int next = Getc(f);
	    if (next == '\n') {
		p--;
		Currline++;
		break;
	    }
	    Ungetc(next,f);
	    column = 0;
	} else if (c == '\f' && stop_opt) {
		p[-1] = '^';
		*p++ = 'L';
		column += 2;
		Pause++;
	} else if (c == EOF) {
	    *length = p - Line;
	    return (column);
	} else {
#ifdef ENABLE_WIDECHAR
	    if (fold_opt && MB_CUR_MAX > 1) {
		memset (mbc, '\0', MB_LEN_MAX);
		mbc_pos = 0;
		mbc[mbc_pos++] = c;
		state_bak = state;

		mblength = mbrtowc (&wc, mbc, mbc_pos, &state);

		/* The value of mblength is always less than 2 here. */
		switch (mblength) {
		  case (size_t)-2:
		    p--;
		    file_pos_bak = Ftell (f) - 1;
		    state = state_bak;
		    use_mbc_buffer_flag = 1;
		    break;

		  case (size_t)-1:
		    state = state_bak;
		    column++;
		    break;

		  default:
		    wc_width = wcwidth (wc);
		    if (wc_width > 0)
		      column += wc_width;
		}
	    } else
#endif
	      {
		if (isprint(c))
		   column++;
	      }
	}

	if (column >= Mcol && fold_opt)
		break;
	c = Getc (f);
    }
    if (column >= Mcol && Mcol > 0) {
	if (!Wrap) {
	    *p++ = '\n';
	}
    }
    colflg = column == Mcol && fold_opt;
    if (colflg && eatnl && Wrap) {
	*p++ = '\n'; /* simulate normal wrap */
    }
    *length = p - Line;
    *p = 0;
    return (column);
}

/*
** Erase the rest of the prompt, assuming we are starting at column col.
*/

void erasep (register int col)
{

    if (promptlen == 0)
	return;
    if (hard) {
	putchar ('\n');
    }
    else {
	if (col == 0)
	    putchar ('\r');
	if (!dumb && eraseln)
	    my_putstring (eraseln);
	else
	    for (col = promptlen - col; col > 0; col--)
		putchar (' ');
    }
    promptlen = 0;
}

/*
** Erase the current line entirely
*/

void kill_line()
{
    erasep(0);
    if (!eraseln || dumb)
	putchar('\r');
}

/*
 * force clear to end of line
 */
void cleareol()
{
    my_putstring(eraseln);
}

void clreos()
{
    my_putstring(EodClr);
}

/* Print a buffer of n characters */

void prbuf (register char *s, register int n)
{
    register char c;			/* next output character */
    register int state;			/* next output char's UL state */
#define wouldul(s,n)	((n) >= 2 && (((s)[0] == '_' && (s)[1] == '\b') || ((s)[1] == '\b' && (s)[2] == '_')))

    while (--n >= 0)
	if (!ul_opt)
	    putchar (*s++);
	else {
	    if (*s == ' ' && pstate == 0 && ulglitch && wouldul(s+1, n-1)) {
		s++;
		continue;
	    }
	    if ((state = wouldul(s, n)) != 0) {
		c = (*s == '_')? s[2] : *s ;
		n -= 2;
		s += 3;
	    } else
		c = *s++;
	    if (state != pstate) {
		if (c == ' ' && state == 0 && ulglitch && wouldul(s, n-1))
		    state = 1;
		else
		    my_putstring(state ? ULenter : ULexit);
	    }
	    if (c != ' ' || pstate == 0 || state != 0 || ulglitch == 0)
	        putchar(c);
	    if (state && *chUL) {
		putsout(chBS);
		my_putstring(chUL);
	    }
	    pstate = state;
	}
}

/*
**  Clear the screen
*/
void
doclear()
{
    if (Clear && !hard) {
	my_putstring(Clear);

	/* Put out carriage return so that system doesn't
	** get confused by escape sequences when expanding tabs
	*/
	putchar ('\r');
	promptlen = 0;
    }
}

/*
 * Go to home position
 */
void
home()
{
    my_putstring(Home);
}

static int lastcmd, lastarg, lastp;
static int lastcolon;
char shell_line[1000];

/*
** Read a command and do it. A command consists of an optional integer
** argument followed by the command character.  Return the number of lines
** to display in the next screenful.  If there is nothing more to display
** in the current file, zero is returned.
*/

int command (char *filename, register FILE *f)
{
    register int nlines;
    register int retval = 0;
    register int c;
    char colonch;
    int done;
    char comchar, cmdbuf[80];

#define ret(val) retval=val;done++;break

    done = 0;
    if (!errors)
	prompt (filename);
    else
	errors = 0;
    for (;;) {
	nlines = number (&comchar);
	lastp = colonch = 0;
	if (comchar == '.') {	/* Repeat last command */
		lastp++;
		comchar = lastcmd;
		nlines = lastarg;
		if (lastcmd == ':')
			colonch = lastcolon;
	}
	lastcmd = comchar;
	lastarg = nlines;
	if ((cc_t) comchar == otty.c_cc[VERASE]) {
	    kill_line ();
	    prompt (filename);
	    continue;
	}
	switch (comchar) {
	case ':':
	    retval = colon (filename, colonch, nlines);
	    if (retval >= 0)
		done++;
	    break;
	case 'b':
	case ctrl('B'):
	    {
		register int initline;

		if (no_intty) {
		    ringbell();
		    return (-1);
		}

		if (nlines == 0) nlines++;

		putchar ('\r');
		erasep (0);
		putchar('\n');
		if (clreol)
			cleareol ();
		if (nlines != 1)
			printf(_("...back %d pages"), nlines);
		else
			putsout(_("...back 1 page"));
		if (clreol)
			cleareol ();
		putchar('\n');

		initline = Currline - dlines * (nlines + 1);
		if (! noscroll)
		    --initline;
		if (initline < 0) initline = 0;
		Fseek(f, 0L);
		Currline = 0;	/* skiplns() will make Currline correct */
		skiplns(initline, f);
		if (! noscroll) {
		    ret(dlines + 1);
		}
		else {
		    ret(dlines);
		}
	    }
	case ' ':
	case 'z':
	    if (nlines == 0) nlines = dlines;
	    else if (comchar == 'z') dlines = nlines;
	    ret (nlines);
	case 'd':
	case ctrl('D'):
	    if (nlines != 0) nscroll = nlines;
	    ret (nscroll);
	case 'q':
	case 'Q':
	    end_it (0);
	case 's':
	case 'f':
	case ctrl('F'):
	    if (nlines == 0) nlines++;
	    if (comchar == 'f')
		nlines *= dlines;
	    putchar ('\r');
	    erasep (0);
	    putchar('\n');
	    if (clreol)
		cleareol ();
	    if (nlines == 1)
		    putsout(_("...skipping one line"));
	    else
		    printf(_("...skipping %d lines"), nlines);

	    if (clreol)
		cleareol ();
	    putchar('\n');

	    while (nlines > 0) {
		while ((c = Getc (f)) != '\n')
		    if (c == EOF) {
			retval = 0;
			done++;
			goto endsw;
		    }
		    Currline++;
		    nlines--;
	    }
	    ret (dlines);
	case '\n':
	    if (nlines != 0)
		dlines = nlines;
	    else
		nlines = 1;
	    ret (nlines);
	case '\f':
	    if (!no_intty) {
		doclear ();
		Fseek (f, screen_start.chrctr);
		Currline = screen_start.line;
		ret (dlines);
	    }
	    else {
		ringbell();
		break;
	    }
	case '\'':
	    if (!no_intty) {
		kill_line ();
		putsout(_("\n***Back***\n\n"));
		Fseek (f, context.chrctr);
		Currline = context.line;
		ret (dlines);
	    }
	    else {
		ringbell();
		break;
	    }
	case '=':
	    kill_line ();
	    promptlen = printf("%d", Currline);
	    fflush (stdout);
	    break;
	case 'n':
	    lastp++;
	case '/':
	    if (nlines == 0) nlines++;
	    kill_line ();
	    putchar('/');
	    promptlen = 1;
	    fflush (stdout);
	    if (lastp) {
		putcerr('\r');
		search (NULL, f, nlines);	/* Use previous r.e. */
	    }
	    else {
		ttyin (cmdbuf, sizeof(cmdbuf)-2, '/');
		putcerr('\r');
		search (cmdbuf, f, nlines);
	    }
	    ret (dlines-1);
	case '!':
	    do_shell (filename);
	    break;
	case '?':
	case 'h':
	    if (noscroll) doclear();
	    putsout(_("\n"
"Most commands optionally preceded by integer argument k.  "
"Defaults in brackets.\n"
"Star (*) indicates argument becomes new default.\n"));
	    puts("---------------------------------------"
		"----------------------------------------");
	    putsout(_(
"<space>                 Display next k lines of text [current screen size]\n"
"z                       Display next k lines of text [current screen size]*\n"
"<return>                Display next k lines of text [1]*\n"
"d or ctrl-D             Scroll k lines [current scroll size, initially 11]*\n"
"q or Q or <interrupt>   Exit from more\n"
"s                       Skip forward k lines of text [1]\n"
"f                       Skip forward k screenfuls of text [1]\n"
"b or ctrl-B             Skip backwards k screenfuls of text [1]\n"
"'                       Go to place where previous search started\n"
"=                       Display current line number\n"
"/<regular expression>   Search for kth occurrence of regular expression [1]\n"
"n                       Search for kth occurrence of last r.e [1]\n"
"!<cmd> or :!<cmd>       Execute <cmd> in a subshell\n"
"v                       Start up /usr/bin/vi at current line\n"
"ctrl-L                  Redraw screen\n"
":n                      Go to kth next file [1]\n"
":p                      Go to kth previous file [1]\n"
":f                      Display current file name and line number\n"
".                       Repeat previous command\n"));
	    puts("---------------------------------------"
		"----------------------------------------");
	    prompt(filename);
	    break;
	case 'v':	/* This case should go right before default */
	    if (!no_intty) {
		    /*
		     * Earlier: call vi +n file. This also works for emacs.
		     * POSIX: call vi -c n file (when editor is vi or ex).
		     */
		    char *editor, *p;
		    int n = (Currline - dlines <= 0 ? 1 :
			     Currline - (dlines + 1) / 2);
		    int split = 0;

		    editor = getenv("VISUAL");
		    if (editor == NULL || *editor == '\0')
			    editor = getenv("EDITOR");
		    if (editor == NULL || *editor == '\0')
			    editor = VI;

		    p = strrchr(editor, '/');
		    if (p)
			    p++;
		    else
			    p = editor;
		    if (!strcmp(p, "vi") || !strcmp(p, "ex")) {
			    sprintf(cmdbuf, "-c %d", n);
			    split = 1;
		    } else {
			    sprintf(cmdbuf, "+%d", n);
		    }

		    kill_line();
		    printf("%s %s %s", editor, cmdbuf, fnames[fnum]);
		    if (split) {
			    cmdbuf[2] = 0;
			    execute(filename, editor, editor, cmdbuf,
				    cmdbuf+3, fnames[fnum], (char *)0);
		    } else
			    execute(filename, editor, editor,
				    cmdbuf, fnames[fnum], (char *)0);
		    break;
	    }
	    /* fall through */
	default:
	    if (dum_opt) {
   		kill_line ();
		if (Senter && Sexit) {
		    my_putstring (Senter);
		    promptlen = printf(_("[Press 'h' for instructions.]"))
			    + 2 * soglitch;
		    my_putstring (Sexit);
		}
		else
		    promptlen = printf(_("[Press 'h' for instructions.]"));
		fflush (stdout);
	    }
	    else
		ringbell();
	    break;
	}
	if (done) break;
    }
    putchar ('\r');
endsw:
    inwait = 0;
    notell++;
    return (retval);
}

static char ch;

/*
 * Execute a colon-prefixed command.
 * Returns <0 if not a command that should cause
 * more of the file to be printed.
 */

int colon (char *filename, int cmd, int nlines) {
	if (cmd == 0)
		ch = readch ();
	else
		ch = cmd;
	lastcolon = ch;
	switch (ch) {
	case 'f':
		kill_line ();
		if (!no_intty)
			promptlen = printf(_("\"%s\" line %d"), fnames[fnum], Currline);
		else
			promptlen = printf(_("[Not a file] line %d"), Currline);
		fflush (stdout);
		return (-1);
	case 'n':
		if (nlines == 0) {
			if (fnum >= nfiles - 1)
				end_it (0);
			nlines++;
		}
		putchar ('\r');
		erasep (0);
		skipf (nlines);
		return (0);
	case 'p':
		if (no_intty) {