pg.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

					break;
				}
				kill_line();
				sopr("saving file ",1);
				sopr(cmdptr,1);
				fflush(stdout);
				save_input(sf);
				error("saved");
			}
			fclose(sf);
			break;
		case 'q':
		case 'Q':
			CHECKEND();
			inwait = 0;
			end_it();
		case 'f':       /* skip forward screenfuls */
			CHECKEND();
			if (sign == 0)
				sign++;	/* skips are always relative */
			if (nlines == 0)
				nlines++;
			nlines = nlines * (window - 1);
			if (sign == 1)
				new_ss.first_line = old_ss.last_line + nlines;
			else
				new_ss.first_line = old_ss.first_line - nlines;
			new_ss.last_line = new_ss.first_line + window - 1;
			inwait = 0;
			return(0);
		case 'l':       /* get a line */
			CHECKEND();
			if (nlines == 0) {
				nlines++;
				if (sign == 0)
					sign = 1;
			}
			switch(sign){
			case 1:
				new_ss.last_line = old_ss.last_line + nlines;
				new_ss.first_line = new_ss.last_line - window + 1;
				break;
			case 0:  /* leave addressed line at top */
				new_ss.first_line = nlines;
				new_ss.last_line = nlines + window - 1;
				break;
			case -1:
				new_ss.first_line = old_ss.first_line - nlines;
				new_ss.last_line = new_ss.first_line + window - 1;
				break;
			}
			inwait = 0;
			return(0);
		case '\0': /* \n or blank */
			if (nlines == 0){
				nlines++;
				if (sign == 0)
					sign = 1;
			}
			nlines = (nlines - 1) * (window - 1);
			switch(sign) {
			case 1:
				new_ss.first_line = old_ss.last_line + nlines;
				new_ss.last_line = new_ss.first_line + window - 1;
				break;
			case 0:
				new_ss.first_line = nlines + 1;
				new_ss.last_line = nlines + window;
				break;
			case -1:
				new_ss.last_line = old_ss.first_line - nlines;
				new_ss.first_line = new_ss.last_line - window + 1;
				break;
			}
			inwait = 0;
			return(0);
		case 'n':       /* switch to next file in arglist */
			CHECKEND();
			if (sign == 0)
				sign = 1;
			if (nlines == 0)
				nlines++;
			if ((skip = skipf(sign *nlines)) == 0) {
				BEEP();
				break;
			}
			inwait = 0;
			return(skip);
		case 'p':       /* switch to previous file in arglist */
			CHECKEND();
			if (sign == 0)
				sign = 1;
			if (nlines == 0)
				nlines++;
			if ((skip = skipf(-sign * nlines)) == 0) {
				BEEP();
				break;
			}
			inwait = 0;
			return(skip);
		case '$':       /* go to end of file */
			CHECKEND();
			sign = 1;
			while(find(1,10000) != EOF)
				/* any large number will do */;
			new_ss.last_line = eofl_no - 1;
			new_ss.first_line = eofl_no - window;
			inwait = 0;
			return(0);
		case '/':       /* search forward for r.e. */
		case '?':       /*   "  backwards */
		case '^':	/* this ones a ? for regent100s */
			if(sign < 0) {
				BEEP();
				break;
			}
			if (nlines == 0)
				nlines++;
			cmdptr--;
			cmdend = cmdptr + (strlen(cmdptr) - 1);
			if ( (cmdend > cmdptr + 1)
				&& (*cmdptr ==  *(cmdend - 1))
				&& ( ((c = *cmdend) == 't')
					|| (c == 'm')
					|| (c == 'b') ) ) {
				leave_search = c;
				cmdend--;
			}
			if ((cmdptr < cmdend) && (*cmdptr == *cmdend))
				*cmdend = '\0';
			if (*cmdptr != '/')  /* signify back search by - */
				nlines = -nlines;
			if (!search(++cmdptr, nlines))
				break;
			else {
				inwait = 0;
				return(0);
			}
		case '!':       /* shell escape */
			if (!hard_copy) { /* redisplay the command */
				pr(cmdbuf);
				pr("\n");
			}
			if ((id = fork ()) < 0) {
				error("cannot fork, try again later");
				break;
			}
			if (id == 0) {
				/*
				* if stdin is a pipe, need to close it so
				* that the terminal is really stdin for
				* the command
				*/
				fclose(stdin);
				dup(fileno(stdout));
				execl(shell, shell, "-c", cmdptr, 0);
				fprintf(stderr,"exec failed\n");
				exit(1);
			}
			signal (SIGINT, SIG_IGN);
			signal (SIGQUIT, SIG_IGN);
			wait ((int *) 0);
			pr("!\n");
			fflush(stdout);
			signal(SIGINT,on_brk);
			signal(SIGQUIT,on_brk);
			break;
		default:
			BEEP();
			break;
		}
	}
}

number()
{
	register int i;
	register char *p;

	i = 0;
	sign = 0;
	p = cmdptr;
	BLANKS(p);
	if (*p == '+') {
		p++;
		sign = 1;
	}
	else
	if (*p == '-') {
		p++;
		sign = -1;
	}
	while (isdigit(*p))
		i = i * 10 + *p++ - '0';
	cmdptr = p;
	return(i);
}

ttyin ()
{
	register char *sptr;
	register char ch;
	register int slash = 0;
	int state = 0;

	fixterm();
	set_state(&state,' ',NULL);	/* initialize state processing */
	sptr = cmdbuf;
	while(state != 10) {
		ch = readch();
		if (ch == '\n' && !slash)
			break;
		if (ch == erasechar() && !slash) {
			if (sptr > cmdbuf) {
				--promptlen;
				pr("\b \b");
				--sptr;
				if (*sptr < ' ') {
					--promptlen;
					pr("\b \b");
				}
			}
			set_state(&state,ch,sptr);
			fflush(stdout);
			continue;
		}
		else
		if (ch == killchar() && !slash) {
			if (hard_copy)
				putchar(ch);
			resetterm();
			return(1);
		}
		if (slash) {
			slash = 0;
			pr("\b \b");
			sptr--;
			promptlen--;
		}
		else /* is there room to keep this character? */
		if (sptr>=cmdbuf + sizeof(cmdbuf) || promptlen + 2 >= columns) {
			BEEP();
			continue;
		}
		else
		if (ch == '\\')
			slash++;
		if (set_state(&state,ch,sptr) == 0) {
			BEEP();
			continue;
		}
		*sptr++ = ch;
		if (ch < ' ') {
			ch += 0100;
			putchar('^');
			promptlen++;
		}
		putchar(ch);
		promptlen++;
		fflush(stdout);
	}

	*sptr = '\0';
	kill_line();
	fflush(stdout);
	resetterm();
	return(0);
}

set_state(pstate,c,pc)
register int *pstate;
register int c;
register char *pc;
{
	static char *psign;
	static char *pnumber;
	static char *pcommand;
	static int slash;

	if (*pstate == 0) {
		psign = NULL;
		pnumber = NULL;
		pcommand = NULL;
		*pstate = 1;
		slash = 0;
		return(1);
	}
	if (c == '\\' && !slash) {
		slash++;
		return(1);
	}
	if (c == erasechar() && !slash)
		switch(*pstate) {
		case 4:
			if (pc > pcommand)
				return(1);
			pcommand = NULL;
		case 3:
			if (pnumber && pc > pnumber) {
				*pstate = 3;
				return(1);
			}
			pnumber = NULL;
		case 2:
			if (psign && pc > psign) {
				*pstate = 2;
				return(1);
			}
			psign = NULL;
		case 1:
			*pstate = 1;
			return(1);
		}

	slash = 0;
	switch(*pstate) {
	case 1: /* before recieving anything interesting */
		if (c == '\t' || (!nflag && c == ' '))
			return(1);
		if (c == '+' || c == '-') {
			psign = pc;
			*pstate = 2;
			return(1);
		}
	case 2: /* recieved sign, waiting for digit */
		if (isdigit(c)) {
			pnumber = pc;
			*pstate = 3;
			return(1);
		}
	case 3: /* recieved digit, waiting for the rest of the number */
		if (isdigit(c))
			return(1);
		if (strchr("h\014.wz\004dqQfl np$",c)) {
			pcommand = pc;
			if (nflag)
				*pstate = 10;
			else
				*pstate = 4;
			return(1);
		}
		if (strchr("s/^?!",c)) {
			pcommand = pc;
			*pstate = 4;
			return(1);
		}
		return(0);
	case 4:
		return(1);
	}
}

readch ()
{
	char ch;

	read (fileno(stdout), &ch, 1);
	return (ch);
}

help()
{
	if (clropt)
		doclear();

	pr("-------------------------------------------------------\n");
	pr("   h               help\n");
	pr("   q or Q          quit\n");
	pr("   <blank> or \\n   next page\n");
	pr("   l               next line\n");
	pr("   d or ^D         display half a page more\n");
	pr("   . or ^L         redisplay current page\n");
	pr("   f               skip the next page forward\n");
	pr("   n               next file\n");
	pr("   p               previous file\n");
	pr("   $               last page\n");
	pr("   w or z          set window size and display next page\n");
	pr("   s savefile      save current file in savefile\n");
	pr("   /pattern/       search forward for pattern\n");
	pr("   ?pattern? or\n");
	pr("   ^pattern^       search backward for pattern\n");
	pr("   !command         execute command\n");
	pr("\n");
	pr("Most commands can be preceeded by a number, as in:\n");
	pr("+1\\n (next page); -1\\n (previous page); 1\\n (page 1).\n");
	pr("\n");
	pr("See the manual page for more detail.\n");
	pr("-------------------------------------------------------\n");
}

/*
 * Skip nskip files in the file list (from the command line). Nskip may be
 * negative.
 */

skipf (nskip)
register int nskip;
{
	if (fnum + nskip < 0) {
		nskip = -fnum;
		if (nskip == 0)
			error("No previous file");
	}
	else
	if (fnum + nskip > nfiles - 1) {
		nskip = (nfiles - 1) - fnum;
		if (nskip == 0)
			error("No next file");
	}
	return(nskip);
}

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

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

	pipe_in = 0;
	if (strcmp(fs,"-") == 0) {
		if (tmp_fin == NULL)
			f = stdin;
		else {
			rewind(tmp_fin);
			f = tmp_fin;
		}
	}
	else {
		if ((f=fopen(fs, "r")) == NULL) {
			fflush(stdout);
			perror(fs);
			return (NULL);
		}
	}
	if (fstat(fileno(f), &stbuf) == -1) {
		fflush(stdout);
		perror(fs);
		return (NULL);
	}
	if (stbuf.st_mode & S_IFDIR) {
		fprintf(stderr,"pg: %s is a directory\n",fs);
		return (NULL);
	}
	if (stbuf.st_mode & S_IFREG) {
		if (f == stdin)		/* It may have been read from */
			rewind(f);	/* already, and not reopened  */
	}
	else {
		if (f != stdin) {
			fprintf(stderr,"pg: special files only handled as standard input\n");
			return(NULL);
		}
		else {
			mktemp(tmp_name);
			if ((fd=creat(tmp_name,0600)) < 0) {
			    fprintf(stderr,"pg: Can't create temp file\n");
			    return(NULL);
			}			
			close(fd);
			if ((tmp_fou = fopen(tmp_name, "w")) == NULL) {
				fprintf(stderr,"pg: Can't get temp file for writing\n");
				return(NULL);
			}
			if ((tmp_fin = fopen(tmp_name, "r")) == NULL) {
				fprintf(stderr,"pg: Can't get temp file for reading\n");
				return(NULL);
			}
			pipe_in = 1;
		}
	}
	lineset(BOF);
	return(f);
}

copy_file(f, out)
register FILE *f, *out;
{
	register int c;

	while ((c = getc(f)) != EOF)
		putc(c,out);
}

#define INIT		register char *sp = instring;
#define GETC()		(*sp++)
#define PEEKC()		(*sp)
#define UNGETC()	(--sp)
#define RETURN(c)	return
#define ERROR(c)	re_error(c)

#include <regexp.h>
re_error(i)
int i;
{
	int j;
	static struct messages {
		char *message;
		int number;
		} re_errmsg[] = {
		"Pattern not found",				1,
		"Range endpoint too large",			11,
		"Bad number",					16,
		"`\\digit' out of range",			25,
		"Illegal or missing delimeter",			36,
		"No remembered search string",  		41,
		"\\( \\) imbalance",				42,
		"Too many \\(",					43,
		"More than two numbers given in \\{ \\}",	44,
		"} expected after \\",				45,
		"First number exceeds second in \\{ \\}",	46,