| 1 | /* Copyright (C) 2011-2016 Free Software Foundation, Inc. |
| 2 | This file is part of gnulib. |
| 3 | |
| 4 | This program is free software: you can redistribute it and/or modify |
| 5 | it under the terms of the GNU General Public License as published by |
| 6 | the Free Software Foundation; either version 3 of the License, or |
| 7 | (at your option) any later version. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | GNU General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License |
| 15 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 16 | |
| 17 | #include <config.h> |
| 18 | |
| 19 | /* Specification */ |
| 20 | #include <unistd.h> |
| 21 | |
| 22 | #include <errno.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | |
| 26 | #if GNULIB_GETCWD |
| 27 | /* Favor GPL getcwd.c if both getcwd and getcwd-lgpl modules are in use. */ |
| 28 | typedef int dummy; |
| 29 | #else |
| 30 | |
| 31 | /* Get the name of the current working directory, and put it in SIZE |
| 32 | bytes of BUF. Returns NULL if the directory couldn't be determined |
| 33 | (perhaps because the absolute name was longer than PATH_MAX, or |
| 34 | because of missing read/search permissions on parent directories) |
| 35 | or SIZE was too small. If successful, returns BUF. If BUF is |
| 36 | NULL, an array is allocated with 'malloc'; the array is SIZE bytes |
| 37 | long, unless SIZE == 0, in which case it is as big as |
| 38 | necessary. */ |
| 39 | |
| 40 | # undef getcwd |
| 41 | char * |
| 42 | rpl_getcwd (char *buf, size_t size) |
| 43 | { |
| 44 | char *ptr; |
| 45 | char *result; |
| 46 | |
| 47 | /* Handle single size operations. */ |
| 48 | if (buf) |
| 49 | { |
| 50 | if (!size) |
| 51 | { |
| 52 | errno = EINVAL; |
| 53 | return NULL; |
| 54 | } |
| 55 | return getcwd (buf, size); |
| 56 | } |
| 57 | |
| 58 | if (size) |
| 59 | { |
| 60 | buf = malloc (size); |
| 61 | if (!buf) |
| 62 | { |
| 63 | errno = ENOMEM; |
| 64 | return NULL; |
| 65 | } |
| 66 | result = getcwd (buf, size); |
| 67 | if (!result) |
| 68 | { |
| 69 | int saved_errno = errno; |
| 70 | free (buf); |
| 71 | errno = saved_errno; |
| 72 | } |
| 73 | return result; |
| 74 | } |
| 75 | |
| 76 | /* Flexible sizing requested. Avoid over-allocation for the common |
| 77 | case of a name that fits within a 4k page, minus some space for |
| 78 | local variables, to be sure we don't skip over a guard page. */ |
| 79 | { |
| 80 | char tmp[4032]; |
| 81 | size = sizeof tmp; |
| 82 | ptr = getcwd (tmp, size); |
| 83 | if (ptr) |
| 84 | { |
| 85 | result = strdup (ptr); |
| 86 | if (!result) |
| 87 | errno = ENOMEM; |
| 88 | return result; |
| 89 | } |
| 90 | if (errno != ERANGE) |
| 91 | return NULL; |
| 92 | } |
| 93 | |
| 94 | /* My what a large directory name we have. */ |
| 95 | do |
| 96 | { |
| 97 | size <<= 1; |
| 98 | ptr = realloc (buf, size); |
| 99 | if (ptr == NULL) |
| 100 | { |
| 101 | free (buf); |
| 102 | errno = ENOMEM; |
| 103 | return NULL; |
| 104 | } |
| 105 | buf = ptr; |
| 106 | result = getcwd (buf, size); |
| 107 | } |
| 108 | while (!result && errno == ERANGE); |
| 109 | |
| 110 | if (!result) |
| 111 | { |
| 112 | int saved_errno = errno; |
| 113 | free (buf); |
| 114 | errno = saved_errno; |
| 115 | } |
| 116 | else |
| 117 | { |
| 118 | /* Trim to fit, if possible. */ |
| 119 | result = realloc (buf, strlen (buf) + 1); |
| 120 | if (!result) |
| 121 | result = buf; |
| 122 | } |
| 123 | return result; |
| 124 | } |
| 125 | |
| 126 | #endif |