xref: /freebsd/contrib/nvi/ex/ex_cd.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*-
2  * Copyright (c) 1992, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #ifndef lint
13 static const char sccsid[] = "@(#)ex_cd.c	10.10 (Berkeley) 8/12/96";
14 #endif /* not lint */
15 
16 #include <sys/param.h>
17 #include <sys/queue.h>
18 
19 #include <bitstring.h>
20 #include <errno.h>
21 #include <limits.h>
22 #include <pwd.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 
28 #include "../common/common.h"
29 
30 /*
31  * ex_cd -- :cd[!] [directory]
32  *	Change directories.
33  *
34  * PUBLIC: int ex_cd __P((SCR *, EXCMD *));
35  */
36 int
37 ex_cd(sp, cmdp)
38 	SCR *sp;
39 	EXCMD *cmdp;
40 {
41 	struct passwd *pw;
42 	ARGS *ap;
43 	CHAR_T savech;
44 	char *dir, *p, *t;	/* XXX: END OF THE STACK, DON'T TRUST GETCWD. */
45 	char buf[MAXPATHLEN * 2];
46 
47 	/*
48 	 * !!!
49 	 * Historic practice is that the cd isn't attempted if the file has
50 	 * been modified, unless its name begins with a leading '/' or the
51 	 * force flag is set.
52 	 */
53 	if (F_ISSET(sp->ep, F_MODIFIED) &&
54 	    !FL_ISSET(cmdp->iflags, E_C_FORCE) && sp->frp->name[0] != '/') {
55 		msgq(sp, M_ERR,
56     "120|File modified since last complete write; write or use ! to override");
57 		return (1);
58 	}
59 
60 	switch (cmdp->argc) {
61 	case 0:
62 		/* If no argument, change to the user's home directory. */
63 		if ((dir = getenv("HOME")) == NULL) {
64 			if ((pw = getpwuid(getuid())) == NULL ||
65 			    pw->pw_dir == NULL || pw->pw_dir[0] == '\0') {
66 				msgq(sp, M_ERR,
67 			   "121|Unable to find home directory location");
68 				return (1);
69 			}
70 			dir = pw->pw_dir;
71 		}
72 		break;
73 	case 1:
74 		dir = cmdp->argv[0]->bp;
75 		break;
76 	default:
77 		abort();
78 	}
79 
80 	/*
81 	 * Try the current directory first.  If this succeeds, don't display
82 	 * a message, vi didn't historically, and it should be obvious to the
83 	 * user where they are.
84 	 */
85 	if (!chdir(dir))
86 		return (0);
87 
88 	/*
89 	 * If moving to the user's home directory, or, the path begins with
90 	 * "/", "./" or "../", it's the only place we try.
91 	 */
92 	if (cmdp->argc == 0 ||
93 	    (ap = cmdp->argv[0])->bp[0] == '/' ||
94 	    ap->len == 1 && ap->bp[0] == '.' ||
95 	    ap->len >= 2 && ap->bp[0] == '.' && ap->bp[1] == '.' &&
96 	    (ap->bp[2] == '/' || ap->bp[2] == '\0'))
97 		goto err;
98 
99 	/* Try the O_CDPATH option values. */
100 	for (p = t = O_STR(sp, O_CDPATH);; ++p)
101 		if (*p == '\0' || *p == ':') {
102 			/*
103 			 * Empty strings specify ".".  The only way to get an
104 			 * empty string is a leading colon, colons in a row,
105 			 * or a trailing colon.  Or, to put it the other way,
106 			 * if the length is 1 or less, then we're dealing with
107 			 * ":XXX", "XXX::XXXX" , "XXX:", or "".  Since we've
108 			 * already tried dot, we ignore tham all.
109 			 */
110 			if (t < p - 1) {
111 				savech = *p;
112 				*p = '\0';
113 				(void)snprintf(buf,
114 				    sizeof(buf), "%s/%s", t, dir);
115 				*p = savech;
116 				if (!chdir(buf)) {
117 					if (getcwd(buf, sizeof(buf)) != NULL)
118 		msgq_str(sp, M_INFO, buf, "122|New current directory: %s");
119 					return (0);
120 				}
121 			}
122 			t = p + 1;
123 			if (*p == '\0')
124 				break;
125 		}
126 
127 err:	msgq_str(sp, M_SYSERR, dir, "%s");
128 	return (1);
129 }
130