コード例 #1
0
ファイル: ex_subst.c プロジェクト: mosconi/openbsd
static int
s(SCR *sp, EXCMD *cmdp, char *s, regex_t *re, u_int flags)
{
	EVENT ev;
	MARK from, to;
	TEXTH tiq;
	recno_t elno, lno, slno;
	regmatch_t match[10];
	size_t blen, cnt, last, lbclen, lblen, len, llen;
	size_t offset, saved_offset, scno;
	int lflag, nflag, pflag, rflag;
	int didsub, do_eol_match, eflags, empty_ok, eval;
	int linechanged, matched, quit, rval;
	unsigned long ul;
	char *bp, *lb;

	NEEDFILE(sp, cmdp);

	slno = sp->lno;
	scno = sp->cno;

	/*
	 * !!!
	 * Historically, the 'g' and 'c' suffices were always toggled as flags,
	 * so ":s/A/B/" was the same as ":s/A/B/ccgg".  If O_EDCOMPATIBLE was
	 * not set, they were initialized to 0 for all substitute commands.  If
	 * O_EDCOMPATIBLE was set, they were initialized to 0 only if the user
	 * specified substitute/replacement patterns (see ex_s()).
	 */
	if (!O_ISSET(sp, O_EDCOMPATIBLE))
		sp->c_suffix = sp->g_suffix = 0;

	/*
	 * Historic vi permitted the '#', 'l' and 'p' options in vi mode, but
	 * it only displayed the last change.  I'd disallow them, but they are
	 * useful in combination with the [v]global commands.  In the current
	 * model the problem is combining them with the 'c' flag -- the screen
	 * would have to flip back and forth between the confirm screen and the
	 * ex print screen, which would be pretty awful.  We do display all
	 * changes, though, for what that's worth.
	 *
	 * !!!
	 * Historic vi was fairly strict about the order of "options", the
	 * count, and "flags".  I'm somewhat fuzzy on the difference between
	 * options and flags, anyway, so this is a simpler approach, and we
	 * just take it them in whatever order the user gives them.  (The ex
	 * usage statement doesn't reflect this.)
	 */
	lflag = nflag = pflag = rflag = 0;
	if (s == NULL)
		goto noargs;
	for (lno = OOBLNO; *s != '\0'; ++s)
		switch (*s) {
		case ' ':
		case '\t':
			continue;
		case '+':
			++cmdp->flagoff;
			break;
		case '-':
			--cmdp->flagoff;
			break;
		case '0': case '1': case '2': case '3': case '4':
		case '5': case '6': case '7': case '8': case '9':
			if (lno != OOBLNO)
				goto usage;
			errno = 0;
			if ((ul = strtoul(s, &s, 10)) >= UINT_MAX)
				errno = ERANGE;
			if (*s == '\0')		/* Loop increment correction. */
				--s;
			if (errno == ERANGE) {
				if (ul >= UINT_MAX)
					msgq(sp, M_ERR, "Count overflow");
				else
					msgq(sp, M_SYSERR, NULL);
				return (1);
			}
			lno = (recno_t)ul;
			/*
			 * In historic vi, the count was inclusive from the
			 * second address.
			 */
			cmdp->addr1.lno = cmdp->addr2.lno;
			cmdp->addr2.lno += lno - 1;
			if (!db_exist(sp, cmdp->addr2.lno) &&
			    db_last(sp, &cmdp->addr2.lno))
				return (1);
			break;
		case '#':
			nflag = 1;
			break;
		case 'c':
			sp->c_suffix = !sp->c_suffix;

			/* Ex text structure initialization. */
			if (F_ISSET(sp, SC_EX)) {
				memset(&tiq, 0, sizeof(TEXTH));
				TAILQ_INIT(&tiq);
			}
			break;
		case 'g':
			sp->g_suffix = !sp->g_suffix;
			break;
		case 'l':
			lflag = 1;
			break;
		case 'p':
			pflag = 1;
			break;
		case 'r':
			if (LF_ISSET(SUB_FIRST)) {
				msgq(sp, M_ERR,
		    "Regular expression specified; r flag meaningless");
				return (1);
			}
			if (!F_ISSET(sp, SC_RE_SEARCH)) {
				ex_emsg(sp, NULL, EXM_NOPREVRE);
				return (1);
			}
			rflag = 1;
			re = &sp->re_c;
			break;
		default:
			goto usage;
		}

	if (*s != '\0' || (!rflag && LF_ISSET(SUB_MUSTSETR))) {
usage:		ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
		return (1);
	}

noargs:	if (F_ISSET(sp, SC_VI) && sp->c_suffix && (lflag || nflag || pflag)) {
		msgq(sp, M_ERR,
"The #, l and p flags may not be combined with the c flag in vi mode");
		return (1);
	}

	/*
	 * bp:		if interactive, line cache
	 * blen:	if interactive, line cache length
	 * lb:		build buffer pointer.
	 * lbclen:	current length of built buffer.
	 * lblen;	length of build buffer.
	 */
	bp = lb = NULL;
	blen = lbclen = lblen = 0;

	/* For each line... */
	for (matched = quit = 0, lno = cmdp->addr1.lno,
	    elno = cmdp->addr2.lno; !quit && lno <= elno; ++lno) {

		/* Someone's unhappy, time to stop. */
		if (INTERRUPTED(sp))
			break;

		/* Get the line. */
		if (db_get(sp, lno, DBG_FATAL, &s, &llen))
			goto err;

		/*
		 * Make a local copy if doing confirmation -- when calling
		 * the confirm routine we're likely to lose the cached copy.
		 */
		if (sp->c_suffix) {
			if (bp == NULL) {
				GET_SPACE_RET(sp, bp, blen, llen);
			} else
				ADD_SPACE_RET(sp, bp, blen, llen);
			memcpy(bp, s, llen);
			s = bp;
		}

		/* Start searching from the beginning. */
		offset = 0;
		len = llen;

		/* Reset the build buffer offset. */
		lbclen = 0;

		/* Reset empty match flag. */
		empty_ok = 1;

		/*
		 * We don't want to have to do a setline if the line didn't
		 * change -- keep track of whether or not this line changed.
		 * If doing confirmations, don't want to keep setting the
		 * line if change is refused -- keep track of substitutions.
		 */
		didsub = linechanged = 0;

		/* New line, do an EOL match. */
		do_eol_match = 1;

		/* It's not nul terminated, but we pretend it is. */
		eflags = REG_STARTEND;

		/*
		 * The search area is from s + offset to the EOL.
		 *
		 * Generally, match[0].rm_so is the offset of the start
		 * of the match from the start of the search, and offset
		 * is the offset of the start of the last search.
		 */
nextmatch:	match[0].rm_so = 0;
		match[0].rm_eo = len;

		/* Get the next match. */
		eval = regexec(re, (char *)s + offset, 10, match, eflags);

		/*
		 * There wasn't a match or if there was an error, deal with
		 * it.  If there was a previous match in this line, resolve
		 * the changes into the database.  Otherwise, just move on.
		 */
		if (eval == REG_NOMATCH)
			goto endmatch;
		if (eval != 0) {
			re_error(sp, eval, re);
			goto err;
		}
		matched = 1;

		/* Only the first search can match an anchored expression. */
		eflags |= REG_NOTBOL;

		/*
		 * !!!
		 * It's possible to match 0-length strings -- for example, the
		 * command s;a*;X;, when matched against the string "aabb" will
		 * result in "XbXbX", i.e. the matches are "aa", the space
		 * between the b's and the space between the b's and the end of
		 * the string.  There is a similar space between the beginning
		 * of the string and the a's.  The rule that we use (because vi
		 * historically used it) is that any 0-length match, occurring
		 * immediately after a match, is ignored.  Otherwise, the above
		 * example would have resulted in "XXbXbX".  Another example is
		 * incorrectly using " *" to replace groups of spaces with one
		 * space.
		 *
		 * The way we do this is that if we just had a successful match,
		 * the starting offset does not skip characters, and the match
		 * is empty, ignore the match and move forward.  If there's no
		 * more characters in the string, we were attempting to match
		 * after the last character, so quit.
		 */
		if (!empty_ok && match[0].rm_so == 0 && match[0].rm_eo == 0) {
			empty_ok = 1;
			if (len == 0)
				goto endmatch;
			BUILD(sp, s + offset, 1)
			++offset;
			--len;
			goto nextmatch;
		}

		/* Confirm change. */
		if (sp->c_suffix) {
			/*
			 * Set the cursor position for confirmation.  Note,
			 * if we matched on a '$', the cursor may be past
			 * the end of line.
			 */
			from.lno = to.lno = lno;
			from.cno = match[0].rm_so + offset;
			to.cno = match[0].rm_eo + offset;
			/*
			 * Both ex and vi have to correct for a change before
			 * the first character in the line.
			 */
			if (llen == 0)
				from.cno = to.cno = 0;
			if (F_ISSET(sp, SC_VI)) {
				/*
				 * Only vi has to correct for a change after
				 * the last character in the line.
				 *
				 * XXX
				 * It would be nice to change the vi code so
				 * that we could display a cursor past EOL.
				 */
				if (to.cno >= llen)
					to.cno = llen - 1;
				if (from.cno >= llen)
					from.cno = llen - 1;

				sp->lno = from.lno;
				sp->cno = from.cno;
				if (vs_refresh(sp, 1))
					goto err;

				vs_update(sp, "Confirm change? [n]", NULL);

				if (v_event_get(sp, &ev, 0, 0))
					goto err;
				switch (ev.e_event) {
				case E_CHARACTER:
					break;
				case E_EOF:
				case E_ERR:
				case E_INTERRUPT:
					goto lquit;
				default:
					v_event_err(sp, &ev);
					goto lquit;
				}
			} else {
				if (ex_print(sp, cmdp, &from, &to, 0) ||
				    ex_scprint(sp, &from, &to))
					goto lquit;
				if (ex_txt(sp, &tiq, 0, TXT_CR))
					goto err;
				ev.e_c = TAILQ_FIRST(&tiq)->lb[0];
			}

			switch (ev.e_c) {
			case CH_YES:
				break;
			default:
			case CH_NO:
				didsub = 0;
				BUILD(sp, s +offset, match[0].rm_eo);
				goto skip;
			case CH_QUIT:
				/* Set the quit/interrupted flags. */
lquit:				quit = 1;
				F_SET(sp->gp, G_INTERRUPTED);

				/*
				 * Resolve any changes, then return to (and
				 * exit from) the main loop.
				 */
				goto endmatch;
			}
		}

		/*
		 * Set the cursor to the last position changed, converting
		 * from 1-based to 0-based.
		 */
		sp->lno = lno;
		sp->cno = match[0].rm_so;

		/* Copy the bytes before the match into the build buffer. */
		BUILD(sp, s + offset, match[0].rm_so);

		/* Substitute the matching bytes. */
		didsub = 1;
		if (re_sub(sp, s + offset, &lb, &lbclen, &lblen, match))
			goto err;

		/* Set the change flag so we know this line was modified. */
		linechanged = 1;

		/* Move past the matched bytes. */
skip:		offset += match[0].rm_eo;
		len -= match[0].rm_eo;

		/* A match cannot be followed by an empty pattern. */
		empty_ok = 0;

		/*
		 * If doing a global change with confirmation, we have to
		 * update the screen.  The basic idea is to store the line
		 * so the screen update routines can find it, and restart.
		 */
		if (didsub && sp->c_suffix && sp->g_suffix) {
			/*
			 * The new search offset will be the end of the
			 * modified line.
			 */
			saved_offset = lbclen;

			/* Copy the rest of the line. */
			if (len)
				BUILD(sp, s + offset, len)

			/* Set the new offset. */
			offset = saved_offset;

			/* Store inserted lines, adjusting the build buffer. */
			last = 0;
			if (sp->newl_cnt) {
				for (cnt = 0;
				    cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
					if (db_insert(sp, lno,
					    lb + last, sp->newl[cnt] - last))
						goto err;
					last = sp->newl[cnt] + 1;
					++sp->rptlines[L_ADDED];
				}
				lbclen -= last;
				offset -= last;
				sp->newl_cnt = 0;
			}

			/* Store and retrieve the line. */
			if (db_set(sp, lno, lb + last, lbclen))
				goto err;
			if (db_get(sp, lno, DBG_FATAL, &s, &llen))
				goto err;
			ADD_SPACE_RET(sp, bp, blen, llen)
			memcpy(bp, s, llen);
			s = bp;
			len = llen - offset;

			/* Restart the build. */
			lbclen = 0;
			BUILD(sp, s, offset);

			/*
			 * If we haven't already done the after-the-string
			 * match, do one.  Set REG_NOTEOL so the '$' pattern
			 * only matches once.
			 */
			if (!do_eol_match)
				goto endmatch;
			if (offset == len) {
				do_eol_match = 0;
				eflags |= REG_NOTEOL;
			}
			goto nextmatch;
		}

		/*
		 * If it's a global:
		 *
		 * If at the end of the string, do a test for the after
		 * the string match.  Set REG_NOTEOL so the '$' pattern
		 * only matches once.
		 */
		if (sp->g_suffix && do_eol_match) {
			if (len == 0) {
				do_eol_match = 0;
				eflags |= REG_NOTEOL;
			}
			goto nextmatch;
		}

endmatch:	if (!linechanged)
			continue;

		/* Copy any remaining bytes into the build buffer. */
		if (len)
			BUILD(sp, s + offset, len)

		/* Store inserted lines, adjusting the build buffer. */
		last = 0;
		if (sp->newl_cnt) {
			for (cnt = 0;
			    cnt < sp->newl_cnt; ++cnt, ++lno, ++elno) {
				if (db_insert(sp,
				    lno, lb + last, sp->newl[cnt] - last))
					goto err;
				last = sp->newl[cnt] + 1;
				++sp->rptlines[L_ADDED];
			}
			lbclen -= last;
			sp->newl_cnt = 0;
		}

		/* Store the changed line. */
		if (db_set(sp, lno, lb + last, lbclen))
			goto err;

		/* Update changed line counter. */
		if (sp->rptlchange != lno) {
			sp->rptlchange = lno;
			++sp->rptlines[L_CHANGED];
		}

		/*
		 * !!!
		 * Display as necessary.  Historic practice is to only
		 * display the last line of a line split into multiple
		 * lines.
		 */
		if (lflag || nflag || pflag) {
			from.lno = to.lno = lno;
			from.cno = to.cno = 0;
			if (lflag)
				(void)ex_print(sp, cmdp, &from, &to, E_C_LIST);
			if (nflag)
				(void)ex_print(sp, cmdp, &from, &to, E_C_HASH);
			if (pflag)
				(void)ex_print(sp, cmdp, &from, &to, E_C_PRINT);
		}
	}

	/*
	 * !!!
	 * Historically, vi attempted to leave the cursor at the same place if
	 * the substitution was done at the current cursor position.  Otherwise
	 * it moved it to the first non-blank of the last line changed.  There
	 * were some problems: for example, :s/$/foo/ with the cursor on the
	 * last character of the line left the cursor on the last character, or
	 * the & command with multiple occurrences of the matching string in the
	 * line usually left the cursor in a fairly random position.
	 *
	 * We try to do the same thing, with the exception that if the user is
	 * doing substitution with confirmation, we move to the last line about
	 * which the user was consulted, as opposed to the last line that they
	 * actually changed.  This prevents a screen flash if the user doesn't
	 * change many of the possible lines.
	 */
	if (!sp->c_suffix && (sp->lno != slno || sp->cno != scno)) {
		sp->cno = 0;
		(void)nonblank(sp, sp->lno, &sp->cno);
	}

	/*
	 * If not in a global command, and nothing matched, say so.
	 * Else, if none of the lines displayed, put something up.
	 */
	rval = 0;
	if (!matched) {
		if (!F_ISSET(sp, SC_EX_GLOBAL)) {
			msgq(sp, M_ERR, "No match found");
			goto err;
		}
	} else if (!lflag && !nflag && !pflag)
		F_SET(cmdp, E_AUTOPRINT);

	if (0) {
err:		rval = 1;
	}

	if (bp != NULL)
		FREE_SPACE(sp, bp, blen);
	if (lb != NULL)
		free(lb);
	return (rval);
}
コード例 #2
0
ファイル: ex_read.c プロジェクト: fishman/nvi
/*
 * ex_read --	:read [file]
 *		:read [!cmd]
 *	Read from a file or utility.
 *
 * !!!
 * Historical vi wouldn't undo a filter read, for no apparent reason.
 *
 * PUBLIC: int ex_read __P((SCR *, EXCMD *));
 */
int
ex_read(SCR *sp, EXCMD *cmdp)
{
	enum { R_ARG, R_EXPANDARG, R_FILTER } which;
	struct stat sb;
	CHAR_T *arg;
	char *name;
	size_t nlen;
	EX_PRIVATE *exp;
	FILE *fp;
	FREF *frp;
	GS *gp;
	MARK rm;
	db_recno_t nlines;
	size_t arglen;
	int argc, rval;
	char *p;
	char *np;

	gp = sp->gp;

	/*
	 * 0 args: read the current pathname.
	 * 1 args: check for "read !arg".
	 */
	switch (cmdp->argc) {
	case 0:
		which = R_ARG;
		break;
	case 1:
		arg = cmdp->argv[0]->bp;
		arglen = cmdp->argv[0]->len;
		if (*arg == '!') {
			++arg;
			--arglen;
			which = R_FILTER;

			/* Secure means no shell access. */
			if (O_ISSET(sp, O_SECURE)) {
				ex_wemsg(sp, cmdp->cmd->name, EXM_SECURE_F);
				return (1);
			}
		} else
			which = R_EXPANDARG;
		break;
	default:
		abort();
		/* NOTREACHED */
	}

	/* Load a temporary file if no file being edited. */
	if (sp->ep == NULL) {
		if ((frp = file_add(sp, NULL)) == NULL)
			return (1);
		if (file_init(sp, frp, NULL, 0))
			return (1);
	}

	switch (which) {
	case R_FILTER:
		/*
		 * File name and bang expand the user's argument.  If
		 * we don't get an additional argument, it's illegal.
		 */
		argc = cmdp->argc;
		if (argv_exp1(sp, cmdp, arg, arglen, 1))
			return (1);
		if (argc == cmdp->argc) {
			ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
			return (1);
		}
		argc = cmdp->argc - 1;

		/* Set the last bang command. */
		exp = EXP(sp);
		if (exp->lastbcomm != NULL)
			free(exp->lastbcomm);
		if ((exp->lastbcomm =
		    v_wstrdup(sp, cmdp->argv[argc]->bp,
				cmdp->argv[argc]->len)) == NULL) {
			msgq(sp, M_SYSERR, NULL);
			return (1);
		}

		/*
		 * Vi redisplayed the user's argument if it changed, ex
		 * always displayed a !, plus the user's argument if it
		 * changed.
		 */
		if (F_ISSET(sp, SC_VI)) {
			if (F_ISSET(cmdp, E_MODIFY))
				(void)vs_update(sp, "!", cmdp->argv[argc]->bp);
		} else {
			if (F_ISSET(cmdp, E_MODIFY))
				(void)ex_printf(sp,
				    "!%s\n", cmdp->argv[argc]->bp);
			else
				(void)ex_puts(sp, "!\n");
			(void)ex_fflush(sp);
		}

		/*
		 * Historically, filter reads as the first ex command didn't
		 * wait for the user. If SC_SCR_EXWROTE not already set, set
		 * the don't-wait flag.
		 */
		if (!F_ISSET(sp, SC_SCR_EXWROTE))
			F_SET(sp, SC_EX_WAIT_NO);

		/*
		 * Switch into ex canonical mode.  The reason to restore the
		 * original terminal modes for read filters is so that users
		 * can do things like ":r! cat /dev/tty".
		 *
		 * !!!
		 * We do not output an extra <newline>, so that we don't touch
		 * the screen on a normal read.
		 */
		if (F_ISSET(sp, SC_VI)) {
			if (gp->scr_screen(sp, SC_EX)) {
				ex_wemsg(sp, cmdp->cmd->name, EXM_NOCANON_F);
				return (1);
			}
			/*
			 * !!!
			 * Historically, the read command doesn't switch to
			 * the alternate X11 xterm screen, if doing a filter
			 * read -- don't set SA_ALTERNATE.
			 */
			F_SET(sp, SC_SCR_EX | SC_SCR_EXWROTE);
		}

		if (ex_filter(sp, cmdp, &cmdp->addr1,
		    NULL, &rm, cmdp->argv[argc]->bp, FILTER_READ))
			return (1);

		/* The filter version of read set the autoprint flag. */
		F_SET(cmdp, E_AUTOPRINT);

		/*
		 * If in vi mode, move to the first nonblank.  Might have
		 * switched into ex mode, so saved the original SC_VI value.
		 */
		sp->lno = rm.lno;
		if (F_ISSET(sp, SC_VI)) {
			sp->cno = 0;
			(void)nonblank(sp, sp->lno, &sp->cno);
		}
		return (0);
	case R_ARG:
		name = sp->frp->name;
		break;
	case R_EXPANDARG:
		if (argv_exp2(sp, cmdp, arg, arglen))
			return (1);
		/*
		 *  0 args: impossible.
		 *  1 args: impossible (I hope).
		 *  2 args: read it.
		 * >2 args: object, too many args.
		 *
		 * The 1 args case depends on the argv_sexp() function refusing
		 * to return success without at least one non-blank character.
		 */
		switch (cmdp->argc) {
		case 0:
		case 1:
			abort();
			/* NOTREACHED */
		case 2:
			INT2CHAR(sp, cmdp->argv[1]->bp, cmdp->argv[1]->len + 1, 
				 name, nlen);
			/*
			 * !!!
			 * Historically, the read and write commands renamed
			 * "unnamed" files, or, if the file had a name, set
			 * the alternate file name.
			 */
			if (F_ISSET(sp->frp, FR_TMPFILE) &&
			    !F_ISSET(sp->frp, FR_EXNAMED)) {
				if ((p = strdup(name)) != NULL) {
					free(sp->frp->name);
					sp->frp->name = p;
				}
				/*
				 * The file has a real name, it's no longer a
				 * temporary, clear the temporary file flags.
				 */
				F_CLR(sp->frp, FR_TMPEXIT | FR_TMPFILE);
				F_SET(sp->frp, FR_NAMECHANGE | FR_EXNAMED);

				/* Notify the screen. */
				(void)sp->gp->scr_rename(sp, sp->frp->name, 1);
				name = sp->frp->name;
			} else {
				set_alt_name(sp, name);
				name = sp->alt_name;
			}
			break;
		default:
			ex_wemsg(sp, cmdp->argv[0]->bp, EXM_FILECOUNT);
			return (1);
		
		}
		break;
	}

	/*
	 * !!!
	 * Historically, vi did not permit reads from non-regular files, nor
	 * did it distinguish between "read !" and "read!", so there was no
	 * way to "force" it.  We permit reading from named pipes too, since
	 * they didn't exist when the original implementation of vi was done
	 * and they seem a reasonable addition.
	 */
	if ((fp = fopen(name, "r")) == NULL || fstat(fileno(fp), &sb)) {
		msgq_str(sp, M_SYSERR, name, "%s");
		return (1);
	}
	if (!S_ISFIFO(sb.st_mode) && !S_ISREG(sb.st_mode)) {
		(void)fclose(fp);
		msgq(sp, M_ERR,
		    "145|Only regular files and named pipes may be read");
		return (1);
	}

	/* Try and get a lock. */
	if (file_lock(sp, NULL, NULL, fileno(fp), 0) == LOCK_UNAVAIL)
		msgq(sp, M_ERR, "146|%s: read lock was unavailable", name);

	rval = ex_readfp(sp, name, fp, &cmdp->addr1, &nlines, 0);

	/*
	 * In vi, set the cursor to the first line read in, if anything read
	 * in, otherwise, the address.  (Historic vi set it to the line after
	 * the address regardless, but since that line may not exist we don't
	 * bother.)
	 *
	 * In ex, set the cursor to the last line read in, if anything read in,
	 * otherwise, the address.
	 */
	if (F_ISSET(sp, SC_VI)) {
		sp->lno = cmdp->addr1.lno;
		if (nlines)
			++sp->lno;
	} else
		sp->lno = cmdp->addr1.lno + nlines;
	return (rval);
}
コード例 #3
0
ファイル: ex_bang.c プロジェクト: lichray/nvi2
/*
 * ex_bang -- :[line [,line]] ! command
 *
 * Pass the rest of the line after the ! character to the program named by
 * the O_SHELL option.
 *
 * Historical vi did NOT do shell expansion on the arguments before passing
 * them, only file name expansion.  This means that the O_SHELL program got
 * "$t" as an argument if that is what the user entered.  Also, there's a
 * special expansion done for the bang command.  Any exclamation points in
 * the user's argument are replaced by the last, expanded ! command.
 *
 * There's some fairly amazing slop in this routine to make the different
 * ways of getting here display the right things.  It took a long time to
 * get it right (wrong?), so be careful.
 *
 * PUBLIC: int ex_bang(SCR *, EXCMD *);
 */
int
ex_bang(SCR *sp, EXCMD *cmdp)
{
	enum filtertype ftype;
	ARGS *ap;
	EX_PRIVATE *exp;
	MARK rm;
	recno_t lno;
	int rval;
	const char *msg;
	char *np;
	size_t nlen;

	ap = cmdp->argv[0];
	if (ap->len == 0) {
		ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
		return (1);
	}

	/* Set the "last bang command" remembered value. */
	exp = EXP(sp);
	free(exp->lastbcomm);
	if ((exp->lastbcomm = v_wstrdup(sp, ap->bp, ap->len)) == NULL) {
		msgq(sp, M_SYSERR, NULL);
		return (1);
	}

	/*
	 * If the command was modified by the expansion, it was historically
	 * redisplayed.
	 */
	if (F_ISSET(cmdp, E_MODIFY) && !F_ISSET(sp, SC_EX_SILENT)) {
		/*
		 * Display the command if modified.  Historic ex/vi displayed
		 * the command if it was modified due to file name and/or bang
		 * expansion.  If piping lines in vi, it would be immediately
		 * overwritten by any error or line change reporting.
		 */
		if (F_ISSET(sp, SC_VI))
			vs_update(sp, "!", ap->bp);
		else {
			(void)ex_printf(sp, "!"WS"\n", ap->bp);
			(void)ex_fflush(sp);
		}
	}

	/*
	 * If no addresses were specified, run the command.  If there's an
	 * underlying file, it's been modified and autowrite is set, write
	 * the file back.  If the file has been modified, autowrite is not
	 * set and the warn option is set, tell the user about the file.
	 */
	if (cmdp->addrcnt == 0) {
		msg = NULL;
		if (sp->ep != NULL && F_ISSET(sp->ep, F_MODIFIED))
			if (O_ISSET(sp, O_AUTOWRITE)) {
				if (file_aw(sp, FS_ALL))
					return (0);
			} else if (O_ISSET(sp, O_WARN) &&
			    !F_ISSET(sp, SC_EX_SILENT))
				msg = msg_cat(sp,
				    "303|File modified since last write.",
				    NULL);

		/* If we're still in a vi screen, move out explicitly. */
		INT2CHAR(sp, ap->bp, ap->len+1, np, nlen);
		(void)ex_exec_proc(sp,
		    cmdp, np, msg, !F_ISSET(sp, SC_EX | SC_SCR_EXWROTE));
	}

	/*
	 * If addresses were specified, pipe lines from the file through the
	 * command.
	 *
	 * Historically, vi lines were replaced by both the stdout and stderr
	 * lines of the command, but ex lines by only the stdout lines.  This
	 * makes no sense to me, so nvi makes it consistent for both, and
	 * matches vi's historic behavior.
	 */
	else {
		NEEDFILE(sp, cmdp);

		/* Autoprint is set historically, even if the command fails. */
		F_SET(cmdp, E_AUTOPRINT);

		/*
		 * !!!
		 * Historical vi permitted "!!" in an empty file.  When this
		 * happens, we arrive here with two addresses of 1,1 and a
		 * bad attitude.  The simple solution is to turn it into a
		 * FILTER_READ operation, with the exception that stdin isn't
		 * opened for the utility, and the cursor position isn't the
		 * same.  The only historic glitch (I think) is that we don't
		 * put an empty line into the default cut buffer, as historic
		 * vi did.  Imagine, if you can, my disappointment.
		 */
		ftype = FILTER_BANG;
		if (cmdp->addr1.lno == 1 && cmdp->addr2.lno == 1) {
			if (db_last(sp, &lno))
				return (1);
			if (lno == 0) {
				cmdp->addr1.lno = cmdp->addr2.lno = 0;
				ftype = FILTER_RBANG;
			}
		}
		rval = ex_filter(sp, cmdp,
		    &cmdp->addr1, &cmdp->addr2, &rm, ap->bp, ftype);

		/*
		 * If in vi mode, move to the first nonblank.
		 *
		 * !!!
		 * Historic vi wasn't consistent in this area -- if you used
		 * a forward motion it moved to the first nonblank, but if you
		 * did a backward motion it didn't.  And, if you followed a
		 * backward motion with a forward motion, it wouldn't move to
		 * the nonblank for either.  Going to the nonblank generally
		 * seems more useful and consistent, so we do it.
		 */
		sp->lno = rm.lno;
		if (F_ISSET(sp, SC_VI)) {
			sp->cno = 0;
			(void)nonblank(sp, sp->lno, &sp->cno);
		} else
			sp->cno = rm.cno;
	}

	/* Ex terminates with a bang, even if the command fails. */
	if (!F_ISSET(sp, SC_VI) && !F_ISSET(sp, SC_EX_SILENT))
		(void)ex_puts(sp, "!\n");

	/*
	 * XXX
	 * The ! commands never return an error, so that autoprint always
	 * happens in the ex parser.
	 */
	return (0);
}