uspace/app/bdsh/cmds/builtins/cd/cd.c

   1 /*
   2  * Copyright (c) 2008 Tim Post
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <str.h>
  32 #include <errno.h>
  33 #include <vfs/vfs.h>
  34
  35 #include "util.h"
  36 #include "errors.h"
  37 #include "entry.h"
  38 #include "cmds.h"
  39 #include "cd.h"
  40
  41 static const char *cmdname = "cd";
  42
  43 /* Previous directory variables.
  44  *
  45  * Declaring them static to avoid many "== NULL" checks.
  46  * PATH_MAX is not that big to cause any problems with memory overhead.
  47  */
  48 static char previous_directory[PATH_MAX] = "";
  49 static char previous_directory_tmp[PATH_MAX];
  50 static bool previous_directory_valid = true;
  51 static bool previous_directory_set = false;
  52
  53 static errno_t chdir_and_remember(const char *new_dir)
  54 {
  55
  56         errno_t rc = vfs_cwd_get(previous_directory_tmp, PATH_MAX);
  57         previous_directory_valid = (rc == EOK);
  58         previous_directory_set = true;
  59
  60         rc = vfs_cwd_set(new_dir);
  61         if (rc != EOK)
  62                 return rc;
  63
  64         str_cpy(previous_directory, PATH_MAX, previous_directory_tmp);
  65         return EOK;
  66 }
  67
  68 void help_cmd_cd(unsigned int level)
  69 {
  70         if (level == HELP_SHORT) {
  71                 printf("`%s' changes the current working directory.\n", cmdname);
  72         } else {
  73                 printf(
  74                 "  %s <directory>\n"
  75                 "  Change directory to <directory>, e.g `%s /sbin'\n",
  76                         cmdname, cmdname);
  77         }
  78
  79         return;
  80 }
  81
  82
  83 /* This is a very rudamentary 'cd' command. It is not 'link smart' (yet) */
  84
  85 int cmd_cd(char **argv, cliuser_t *usr)
  86 {
  87         int argc;
  88         errno_t rc = EOK;
  89
  90         argc = cli_count_args(argv);
  91
  92         /* Handle cd -- -. Override to switch to a directory named '-' */
  93         bool hyphen_override = false;
  94         char *target_directory = argv[1];
  95         if (argc == 3) {
  96                 if (!str_cmp(argv[1], "--")) {
  97                         hyphen_override = true;
  98                         argc--;
  99                         target_directory = argv[2];
 100                 }
 101         }
 102
 103         /* We don't yet play nice with whitespace, a getopt implementation should
 104          * protect "quoted\ destination" as a single argument. Its not our job to
 105          * look for && || or redirection as the tokenizer should have done that
 106          * (currently, it does not) */
 107
 108         if (argc > 2) {
 109                 cli_error(CL_EFAIL, "Too many arguments to `%s'", cmdname);
 110                 return CMD_FAILURE;
 111         }
 112
 113         if (argc < 2) {
 114                 printf("%s - no directory specified. Try `help %s extended'\n",
 115                         cmdname, cmdname);
 116                 return CMD_FAILURE;
 117         }
 118
 119         /* We have the correct # of arguments */
 120         // TODO: handle tidle (~) expansion? */
 121
 122         /* Handle 'cd -' first. */
 123         if (!str_cmp(target_directory, "-") && !hyphen_override) {
 124                 if (!previous_directory_valid) {
 125                         cli_error(CL_EFAIL, "Cannot switch to previous directory");
 126                         return CMD_FAILURE;
 127                 }
 128                 if (!previous_directory_set) {
 129                         cli_error(CL_EFAIL, "No previous directory to switch to");
 130                         return CMD_FAILURE;
 131                 }
 132                 char *prev_dup = str_dup(previous_directory);
 133                 if (prev_dup == NULL) {
 134                         cli_error(CL_ENOMEM, "Cannot switch to previous directory");
 135                         return CMD_FAILURE;
 136                 }
 137                 rc = chdir_and_remember(prev_dup);
 138                 free(prev_dup);
 139         } else {
 140                 rc = chdir_and_remember(target_directory);
 141         }
 142
 143         if (rc == 0) {
 144                 cli_set_prompt(usr);
 145                 return CMD_SUCCESS;
 146         } else {
 147                 switch (rc) {
 148                 case ENOMEM:
 149                         cli_error(CL_EFAIL, "Destination path too long");
 150                         break;
 151                 case ENOENT:
 152                         cli_error(CL_ENOENT, "Invalid directory `%s'", target_directory);
 153                         break;
 154                 default:
 155                         cli_error(CL_EFAIL, "Unable to change to `%s'", target_directory);
 156                         break;
 157                 }
 158         }
 159
 160         return CMD_FAILURE;
 161 }