xref: /openbsd-src/usr.bin/vi/ex/ex_bang.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: ex_bang.c,v 1.10 2016/01/06 22:29:38 millert Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (c) 1992, 1993, 1994, 1995, 1996
7  *	Keith Bostic.  All rights reserved.
8  *
9  * See the LICENSE file for redistribution information.
10  */
11 
12 #include "config.h"
13 
14 #include <sys/types.h>
15 #include <sys/queue.h>
16 #include <sys/time.h>
17 
18 #include <bitstring.h>
19 #include <errno.h>
20 #include <limits.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25 
26 #include "../common/common.h"
27 #include "../vi/vi.h"
28 
29 /*
30  * ex_bang -- :[line [,line]] ! command
31  *
32  * Pass the rest of the line after the ! character to the program named by
33  * the O_SHELL option.
34  *
35  * Historical vi did NOT do shell expansion on the arguments before passing
36  * them, only file name expansion.  This means that the O_SHELL program got
37  * "$t" as an argument if that is what the user entered.  Also, there's a
38  * special expansion done for the bang command.  Any exclamation points in
39  * the user's argument are replaced by the last, expanded ! command.
40  *
41  * There's some fairly amazing slop in this routine to make the different
42  * ways of getting here display the right things.  It took a long time to
43  * get it right (wrong?), so be careful.
44  *
45  * PUBLIC: int ex_bang(SCR *, EXCMD *);
46  */
47 int
48 ex_bang(SCR *sp, EXCMD *cmdp)
49 {
50 	enum filtertype ftype;
51 	ARGS *ap;
52 	EX_PRIVATE *exp;
53 	MARK rm;
54 	recno_t lno;
55 	int rval;
56 	const char *msg;
57 
58 	ap = cmdp->argv[0];
59 	if (ap->len == 0) {
60 		ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
61 		return (1);
62 	}
63 
64 	/* Set the "last bang command" remembered value. */
65 	exp = EXP(sp);
66 	if (exp->lastbcomm != NULL)
67 		free(exp->lastbcomm);
68 	if ((exp->lastbcomm = strdup(ap->bp)) == NULL) {
69 		msgq(sp, M_SYSERR, NULL);
70 		return (1);
71 	}
72 
73 	/*
74 	 * If the command was modified by the expansion, it was historically
75 	 * redisplayed.
76 	 */
77 	if (F_ISSET(cmdp, E_MODIFY) && !F_ISSET(sp, SC_EX_SILENT)) {
78 		/*
79 		 * Display the command if modified.  Historic ex/vi displayed
80 		 * the command if it was modified due to file name and/or bang
81 		 * expansion.  If piping lines in vi, it would be immediately
82 		 * overwritten by any error or line change reporting.
83 		 */
84 		if (F_ISSET(sp, SC_VI))
85 			vs_update(sp, "!", ap->bp);
86 		else {
87 			(void)ex_printf(sp, "!%s\n", ap->bp);
88 			(void)ex_fflush(sp);
89 		}
90 	}
91 
92 	/*
93 	 * If no addresses were specified, run the command.  If there's an
94 	 * underlying file, it's been modified and autowrite is set, write
95 	 * the file back.  If the file has been modified, autowrite is not
96 	 * set and the warn option is set, tell the user about the file.
97 	 */
98 	if (cmdp->addrcnt == 0) {
99 		msg = NULL;
100 		if (sp->ep != NULL && F_ISSET(sp->ep, F_MODIFIED)) {
101 			if (O_ISSET(sp, O_AUTOWRITE)) {
102 				if (file_aw(sp, FS_ALL))
103 					return (0);
104 			} else if (O_ISSET(sp, O_WARN) &&
105 			    !F_ISSET(sp, SC_EX_SILENT))
106 				msg = "File modified since last write.";
107 		}
108 
109 		/* If we're still in a vi screen, move out explicitly. */
110 		(void)ex_exec_proc(sp,
111 		    cmdp, ap->bp, msg, !F_ISSET(sp, SC_EX | SC_SCR_EXWROTE));
112 	}
113 
114 	/*
115 	 * If addresses were specified, pipe lines from the file through the
116 	 * command.
117 	 *
118 	 * Historically, vi lines were replaced by both the stdout and stderr
119 	 * lines of the command, but ex lines by only the stdout lines.  This
120 	 * makes no sense to me, so nvi makes it consistent for both, and
121 	 * matches vi's historic behavior.
122 	 */
123 	else {
124 		NEEDFILE(sp, cmdp);
125 
126 		/* Autoprint is set historically, even if the command fails. */
127 		F_SET(cmdp, E_AUTOPRINT);
128 
129 		/*
130 		 * !!!
131 		 * Historical vi permitted "!!" in an empty file.  When this
132 		 * happens, we arrive here with two addresses of 1,1 and a
133 		 * bad attitude.  The simple solution is to turn it into a
134 		 * FILTER_READ operation, with the exception that stdin isn't
135 		 * opened for the utility, and the cursor position isn't the
136 		 * same.  The only historic glitch (I think) is that we don't
137 		 * put an empty line into the default cut buffer, as historic
138 		 * vi did.  Imagine, if you can, my disappointment.
139 		 */
140 		ftype = FILTER_BANG;
141 		if (cmdp->addr1.lno == 1 && cmdp->addr2.lno == 1) {
142 			if (db_last(sp, &lno))
143 				return (1);
144 			if (lno == 0) {
145 				cmdp->addr1.lno = cmdp->addr2.lno = 0;
146 				ftype = FILTER_RBANG;
147 			}
148 		}
149 		rval = ex_filter(sp, cmdp,
150 		    &cmdp->addr1, &cmdp->addr2, &rm, ap->bp, ftype);
151 
152 		/*
153 		 * If in vi mode, move to the first nonblank.
154 		 *
155 		 * !!!
156 		 * Historic vi wasn't consistent in this area -- if you used
157 		 * a forward motion it moved to the first nonblank, but if you
158 		 * did a backward motion it didn't.  And, if you followed a
159 		 * backward motion with a forward motion, it wouldn't move to
160 		 * the nonblank for either.  Going to the nonblank generally
161 		 * seems more useful and consistent, so we do it.
162 		 */
163 		sp->lno = rm.lno;
164 		if (F_ISSET(sp, SC_VI)) {
165 			sp->cno = 0;
166 			(void)nonblank(sp, sp->lno, &sp->cno);
167 		} else
168 			sp->cno = rm.cno;
169 	}
170 
171 	/* Ex terminates with a bang, even if the command fails. */
172 	if (!F_ISSET(sp, SC_VI) && !F_ISSET(sp, SC_EX_SILENT))
173 		(void)ex_puts(sp, "!\n");
174 
175 	/*
176 	 * XXX
177 	 * The ! commands never return an error, so that autoprint always
178 	 * happens in the ex parser.
179 	 */
180 	return (0);
181 }
182