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

/*
 * Copyright (C) 1980 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
** more.c - General purpose tty output filter and file perusal program
**
**	by Eric Shienbrood, UC Berkeley
**
**	modified by Geoff Peck, UCB to add underlining, single spacing
**	modified by John Foderaro, UCB to add -c and MORE environment variable
**	modified by Erik Troan <[e-mail]> to be more posix and so compile
**	  on linux/axp.
**	modified by Kars de Jong <[e-mail]> to use terminfo instead
**	  of termcap.
	1999-02-22 Arkadiusz Mi秌iewicz <[e-mail]>
	- added Native Language Support
	1999-03-19 Arnaldo Carvalho de Melo <[e-mail]>
	- more nls translatable strings
	1999-05-09 aeb - applied a RedHat patch (setjmp->sigsetjmp); without it
	a second ^Z would fail.
	1999-05-09 aeb - undone Kars' work, so that more works without
	libcurses (and hence can be in /bin with libcurses being in /usr/lib
	which may not be mounted). However, when termcap is not present curses
	can still be used.
*/

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>		/* for alloca() */
#include <stdarg.h>		/* for va_start() etc */
#include <sys/param.h>
#include <ctype.h>
#include <signal.h>
#include <errno.h>
#include <termios.h>
#include <setjmp.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/wait.h>
#include <a.out.h>
#include <locale.h>
#include "xstrncpy.h"
#include "nls.h"
#include "widechar.h"

#define _REGEX_RE_COMP
#include <regex.h>
#undef _REGEX_RE_COMP

#define VI		"vi"	/* found on the user's path */

#define Fopen(s,m)	(Currline = 0,file_pos=0,fopen(s,m))
#define Ftell(f)	file_pos
#define Fseek(f,off)	(file_pos=off,fseek(f,off,0))
#define Getc(f)		(++file_pos, getc(f))
#define Ungetc(c,f)	(--file_pos, ungetc(c,f))
#define putcerr(c)	fputc(c, stderr)
#define putserr(s)	fputs(s, stderr)
#define putsout(s)	fputs(s, stdout)

#define stty(fd,argp)  tcsetattr(fd,TCSANOW,argp)

/* some function declarations */
void initterm(void);
void kill_line(void);
void doclear(void);
void cleareol(void);
void clreos(void);
void home(void);
void error (char *mess);
void do_shell (char *filename);
int  colon (char *filename, int cmd, int nlines);
int  expand (char **outbuf, char *inbuf);
void argscan(char *s,char *argv0);
void rdline (register FILE *f);
void copy_file(register FILE *f);
void search(char buf[], FILE *file, register int n);
void skipf (register int nskip);
void skiplns(register int n, register FILE *f);
void screen (register FILE *f, register int num_lines);
int  command (char *filename, register FILE *f);
void erasep (register int col);
void show (register char ch);
void set_tty(void);
void reset_tty(void);
void ttyin (unsigned char buf[], register int nmax, char pchar);
int  number(char *cmd);
int  readch (void);
int  get_line(register FILE *f, int *length);
void prbuf (register char *s, register int n);
void execute (char *filename, char *cmd, ...);
FILE *checkf (char *, int *);

#define TBUFSIZ	1024
#define LINSIZ	256
#define ctrl(letter)	(letter & 077)
#define RUBOUT	'\177'
#define ESC	'\033'
#define QUIT	'\034'

struct termios	otty, savetty0;
long		file_pos, file_size;
int		fnum, no_intty, no_tty, slow_tty;
int		dum_opt, dlines;
void		onquit(int), onsusp(int), chgwinsz(int), end_it(int);
int		nscroll = 11;	/* Number of lines scrolled by 'd' */
int		fold_opt = 1;	/* Fold long lines */
int		stop_opt = 1;	/* Stop after form feeds */
int		ssp_opt = 0;	/* Suppress white space */
int		ul_opt = 1;	/* Underline as best we can */
int		promptlen;
int		Currline;	/* Line we are currently at */
int		startup = 1;
int		firstf = 1;
int		notell = 1;
int		docrterase = 0;
int		docrtkill = 0;
int		bad_so;	/* True if overwriting does not turn off standout */
int		inwait, Pause, errors;
int		within;	/* true if we are within a file,
			false if we are between files */
int		hard, dumb, noscroll, hardtabs, clreol, eatnl;
int		catch_susp;	/* We should catch the SIGTSTP signal */
char		**fnames;	/* The list of file names */
int		nfiles;		/* Number of files left to process */
char		*shell;		/* The name of the shell to use */
int		shellp;		/* A previous shell command exists */
sigjmp_buf	restore;
char		Line[LINSIZ+2];	/* Line buffer */
int		Lpp = 24;	/* lines per page */
char		*Clear;		/* clear screen */
char		*eraseln;	/* erase line */
char		*Senter, *Sexit;/* enter and exit standout mode */
char		*ULenter, *ULexit;	/* enter and exit underline mode */
char		*chUL;		/* underline character */
char		*chBS;		/* backspace character */
char		*Home;		/* go to home */
char		*cursorm;	/* cursor movement */
char		cursorhome[40];	/* contains cursor movement to home */
char		*EodClr;	/* clear rest of screen */
int		Mcol = 80;	/* number of columns */
int		Wrap = 1;	/* set if automargins */
int		soglitch;	/* terminal has standout mode glitch */
int		ulglitch;	/* terminal has underline mode glitch */
int		pstate = 0;	/* current UL state */
static int	magic(FILE *, char *);
struct {
    long chrctr, line;
} context, screen_start;
extern char	PC;		/* pad character */

#ifndef HAVE_termcap
#define USE_CURSES
#endif

#ifdef USE_CURSES

#if NCH
#include <ncurses.h>
#else
#include <curses.h>
#endif
#include <term.h>			/* include after <curses.h> */

static void
my_putstring(char *s) {
	tputs (s, 1, putchar);		/* putp(s); */
}

static void
my_setupterm(const char *term, int fildes, int *errret) {
     setupterm(term, fildes, errret);
}

static int
my_tgetnum(char *s, char *ss) {
     return tigetnum(ss);
}

static int
my_tgetflag(char *s, char *ss) {
     return tigetflag(ss);
}

static char *
my_tgetstr(char *s, char *ss) {
     return tigetstr(ss);
}

static char *
my_tgoto(const char *cap, int col, int row) {
     return tparm(cap, col, row);
}

#else /* no CURSES */
#include <termcap.h>

char termbuffer[4096];
char tcbuffer[4096];
char *strbuf = termbuffer;

static void
my_putstring(char *s) {
     tputs (s, 1, putchar);
}

static void
my_setupterm(const char *term, int fildes, int *errret) {
     *errret = tgetent(tcbuffer, term);
}

static int
my_tgetnum(char *s, char *ss) {
     return tgetnum(s);
}

static int
my_tgetflag(char *s, char *ss) {
     return tgetflag(s);
}

static char *
my_tgetstr(char *s, char *ss) {
     return tgetstr(s, &strbuf);
}

static char *
my_tgoto(const char *cap, int col, int row) {
     return tgoto(cap, col, row);
}


#endif /* USE_CURSES */

static void
idummy(int *kk) {}

static void
Fdummy(FILE **ff) {}

static void
usage(char *s) {
	char *p = strrchr(s, '/');
	fprintf(stderr,
		_("usage: %s [-dflpcsu] [+linenum | +/pattern] name1 name2 ...\n"),
		p ? p + 1 : s);
}

int main(int argc, char **argv) {
    FILE	*f;
    char	*s;
    char	*p;
    int		ch;
    int		left;
    int		prnames = 0;
    int		initopt = 0;
    int		srchopt = 0;
    int		clearit = 0;
    int		initline = 0;
    char	initbuf[80];

    setlocale(LC_ALL, "");
    bindtextdomain(PACKAGE, LOCALEDIR);
    textdomain(PACKAGE);
    
    /* avoid gcc complaints about register variables that
       may be clobbered by a longjmp, by forcing our variables here
       to be non-register */
    Fdummy(&f); idummy(&left); idummy(&prnames);
    idummy(&initopt); idummy(&srchopt); idummy(&initline);

    nfiles = argc;
    fnames = argv;
    setlocale(LC_ALL, "");
    initterm ();
    nscroll = Lpp/2 - 1;
    if (nscroll <= 0)
	nscroll = 1;
    if((s = getenv("MORE")) != NULL) argscan(s,argv[0]);
    while (--nfiles > 0) {
	if ((ch = (*++fnames)[0]) == '-') {
	    argscan(*fnames+1,argv[0]);
	}
	else if (ch == '+') {
	    s = *fnames;
	    if (*++s == '/') {
		srchopt++;
		for (++s, p = initbuf; p < initbuf + 79 && *s != '\0';)
		    *p++ = *s++;
		*p = '\0';
	    }
	    else {
		initopt++;
		for (initline = 0; *s != '\0'; s++)
		    if (isdigit (*s))
			initline = initline*10 + *s -'0';
		--initline;
	    }
	}
	else break;
    }
    /* allow clreol only if Home and eraseln and EodClr strings are
     *  defined, and in that case, make sure we are in noscroll mode
     */
    if(clreol)
    {
        if((Home == NULL) || (*Home == '\0') ||
	   (eraseln == NULL) || (*eraseln == '\0') ||
           (EodClr == NULL) || (*EodClr == '\0') )
	      clreol = 0;
	else noscroll = 1;
    }
    if (dlines == 0)
	dlines = Lpp - (noscroll ? 1 : 2);
    left = dlines;
    if (nfiles > 1)
	prnames++;
    if (!no_intty && nfiles == 0) {
	usage(argv[0]);
	exit(1);
    }
    else
	f = stdin;
    if (!no_tty) {
	signal(SIGQUIT, onquit);
	signal(SIGINT, end_it);
#ifdef SIGWINCH
	signal(SIGWINCH, chgwinsz);
#endif
	if (signal (SIGTSTP, SIG_IGN) == SIG_DFL) {
	    signal(SIGTSTP, onsusp);
	    catch_susp++;
	}
	stty (fileno(stderr), &otty);
    }
    if (no_intty) {
	if (no_tty)
	    copy_file (stdin);
	else {
	    if ((ch = Getc (f)) == '\f')
		doclear();
	    else {
		Ungetc (ch, f);
		if (noscroll && (ch != EOF)) {
		    if (clreol)
			home ();
		    else
			doclear ();
		}
	    }
	    if (srchopt)
	    {
		search (initbuf, stdin, 1);
		if (noscroll)
		    left--;
	    }
	    else if (initopt)
		skiplns (initline, stdin);
	    screen (stdin, left);
	}
	no_intty = 0;
	prnames++;
	firstf = 0;
    }

    while (fnum < nfiles) {
	if ((f = checkf (fnames[fnum], &clearit)) != NULL) {
	    context.line = context.chrctr = 0;
	    Currline = 0;
	    if (firstf) sigsetjmp (restore, 1);
	    if (firstf) {
		firstf = 0;
		if (srchopt) {
		    search (initbuf, f, 1);
		    if (noscroll)
			left--;
		}
		else if (initopt)
		    skiplns (initline, f);
	    }
	    else if (fnum < nfiles && !no_tty) {
		sigsetjmp (restore, 1);
		left = command (fnames[fnum], f);
	    }
	    if (left != 0) {
		if ((noscroll || clearit) && (file_size != LONG_MAX)) {
		    if (clreol)
			home ();
		    else
			doclear ();
		}
		if (prnames) {
		    if (bad_so)
			erasep (0);
		    if (clreol)
			cleareol ();
		    putsout("::::::::::::::");
		    if (promptlen > 14)
			erasep (14);
		    putchar('\n');
		    if(clreol) cleareol();
		    puts(fnames[fnum]);
		    if(clreol) cleareol();
		    puts("::::::::::::::");
		    if (left > Lpp - 4)
			left = Lpp - 4;
		}
		if (no_tty)
		    copy_file (f);
		else {
		    within++;
		    screen(f, left);
		    within = 0;
		}
	    }
	    sigsetjmp (restore, 1);
	    fflush(stdout);
	    fclose(f);
	    screen_start.line = screen_start.chrctr = 0L;
	    context.line = context.chrctr = 0L;
	}
	fnum++;
	firstf = 0;
    }
    reset_tty ();
    exit(0);
}

void argscan(char *s, char *argv0) {
	int seen_num = 0;

	while (*s != '\0') {
		switch (*s) {
		  case '0': case '1': case '2':
		  case '3': case '4': case '5':
		  case '6': case '7': case '8':
		  case '9':
			if (!seen_num) {
				dlines = 0;
				seen_num = 1;
			}
			dlines = dlines*10 + *s - '0';
			break;
		  case 'd':
			dum_opt = 1;
			break;
		  case 'l':
			stop_opt = 0;
			break;
		  case 'f':
			fold_opt = 0;
			break;
		  case 'p':
			noscroll++;
			break;
		  case 'c':
			clreol++;
			break;
		  case 's':
			ssp_opt = 1;
			break;
		  case 'u':
			ul_opt = 0;
			break;
		  case '-': case ' ': case '\t':
			break;
		  default:
			fprintf(stderr,
				_("%s: unknown option \"-%c\"\n"), argv0, *s);
			usage(argv0);
			exit(1);
			break;
		}
		s++;
	}
}


/*
** Check whether the file named by fs is an ASCII file which the user may
** access.  If it is, return the opened file. Otherwise return NULL.
*/

FILE *
checkf (fs, clearfirst)
	register char *fs;
	int *clearfirst;
{
	struct stat stbuf;
	register FILE *f;
	int c;

	if (stat (fs, &stbuf) == -1) {
		(void)fflush(stdout);
		if (clreol)
			cleareol ();
		perror(fs);
		return((FILE *)NULL);
	}
	if ((stbuf.st_mode & S_IFMT) == S_IFDIR) {
		printf(_("\n*** %s: directory ***\n\n"), fs);
		return((FILE *)NULL);
	}
	if ((f = Fopen(fs, "r")) == NULL) {
		(void)fflush(stdout);
		perror(fs);
		return((FILE *)NULL);
	}
	if (magic(f, fs))
		return((FILE *)NULL);
	c = Getc(f);
	*clearfirst = (c == '\f');
	Ungetc (c, f);
	if ((file_size = stbuf.st_size) == 0)
		file_size = LONG_MAX;
	return(f);
}

/*
 * magic --
 *	check for file magic numbers.  This code would best be shared with
 *	the file(1) program or, perhaps, more should not try and be so smart?
 */
static int
magic(f, fs)
	FILE *f;
	char *fs;
{
	char twobytes[2];

	/* don't try to look ahead if the input is unseekable */
	if (fseek(f, 0L, SEEK_SET))
		return(0);

	if (fread(twobytes, 2, 1, f) == 1) {
		switch(twobytes[0] + (twobytes[1]<<8)) {
		case OMAGIC:	/* 0407 */
		case NMAGIC:	/* 0410 */
		case ZMAGIC:	/* 0413 */
		case 0405:
		case 0411:
		case 0177545:
		case 0x457f:		/* simple ELF detection */
			printf(_("\n******** %s: Not a text file ********\n\n"), fs);
			(void)fclose(f);
			return(1);
		}
	}
	(void)fseek(f, 0L, SEEK_SET);		/* rewind() not necessary */
	return(0);
}

/*
** Print out the contents of the file f, one screenful at a time.
*/

#define STOP -10

void screen (register FILE *f, register int num_lines)
{
    register int c;
    register int nchars;
    int length;			/* length of current line */
    static int prev_len = 1;	/* length of previous line */

    for (;;) {
	while (num_lines > 0 && !Pause) {
	    if ((nchars = get_line (f, &length)) == EOF)
	    {
		if (clreol)
		    clreos();
		return;
	    }
	    if (ssp_opt && length == 0 && prev_len == 0)
		continue;
	    prev_len = length;
	    if (bad_so || ((Senter && *Senter == ' ') && (promptlen > 0)))
		erasep (0);
	    /* must clear before drawing line since tabs on some terminals
	     * do not erase what they tab over.
	     */
	    if (clreol)
		cleareol ();
	    prbuf (Line, length);
	    if (nchars < promptlen)
		erasep (nchars);	/* erasep () sets promptlen to 0 */
	    else promptlen = 0;
	    /* is this needed?
	     * if (clreol)
	     *	cleareol();	* must clear again in case we wrapped *
	     */
	    if (nchars < Mcol || !fold_opt)
		prbuf("\n", 1);	/* will turn off UL if necessary */
	    if (nchars == STOP)
		break;
	    num_lines--;
	}
	if (pstate) {
		my_putstring (ULexit);
		pstate = 0;
	}
	fflush(stdout);
	if ((c = Getc(f)) == EOF)
	{
	    if (clreol)
		clreos ();
	    return;
	}

	if (Pause && clreol)
	    clreos ();
	Ungetc (c, f);
	sigsetjmp (restore, 1);
	Pause = 0; startup = 0;
	if ((num_lines = command (NULL, f)) == 0)
	    return;
	if (hard && promptlen > 0)
		erasep (0);
	if (noscroll && num_lines >= dlines)
	{
	    if (clreol)
		home();
	    else
		doclear ();
	}
	screen_start.line = Currline;
	screen_start.chrctr = Ftell (f);
    }
}

/*
** Come here if a quit signal is received
*/

void onquit(int dummy) {
    signal(SIGQUIT, SIG_IGN);
    if (!inwait) {
	putchar ('\n');
	if (!startup) {
	    signal(SIGQUIT, onquit);
	    siglongjmp (restore, 1);
	}
	else
	    Pause++;
    }
    else if (!dum_opt && notell) {
	promptlen += fprintf(stderr, _("[Use q or Q to quit]"));
	notell = 0;
    }
    signal(SIGQUIT, onquit);
}

/*
** Come here if a signal for a window size change is received
*/

#ifdef SIGWINCH
void chgwinsz(int dummy) {
    struct winsize win;

    (void) signal(SIGWINCH, SIG_IGN);
    if (ioctl(fileno(stdout), TIOCGWINSZ, &win) != -1) {
	if (win.ws_row != 0) {
	    Lpp = win.ws_row;
	    nscroll = Lpp/2 - 1;
	    if (nscroll <= 0)
		nscroll = 1;
	    dlines = Lpp - (noscroll ? 1 : 2);
	}
	if (win.ws_col != 0)
	    Mcol = win.ws_col;
    }
    (void) signal(SIGWINCH, chgwinsz);
}
#endif

/*
** Clean up terminal state and exit. Also come here if interrupt signal received
*/

void end_it (int dummy) {
    reset_tty ();
    if (clreol) {
	putchar ('\r');
	clreos ();
	fflush (stdout);
    }
    else if (!clreol && (promptlen > 0)) {
	kill_line ();
	fflush (stdout);
    }