ex/ex_cd.c

   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[] = "$Id: ex_cd.c,v 10.10 1996/08/12 20:23:59 bostic Exp $ (Berkeley) $Date: 1996/08/12 20:23:59 $";
  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 }