135 lines
3.3 KiB
C
135 lines
3.3 KiB
C
/* Copyright (C) 2011-2021 Free Software Foundation, Inc.
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This file is part of gnulib.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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#include <config.h>
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/* Specification */
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#include <unistd.h>
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#include <errno.h>
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#include <stdlib.h>
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#include <string.h>
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#if GNULIB_GETCWD
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/* Favor GPL getcwd.c if both getcwd and getcwd-lgpl modules are in use. */
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typedef int dummy;
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#else
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/* Get the name of the current working directory, and put it in SIZE
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bytes of BUF. Returns NULL if the directory couldn't be determined
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(perhaps because the absolute name was longer than PATH_MAX, or
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because of missing read/search permissions on parent directories)
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or SIZE was too small. If successful, returns BUF. If BUF is
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NULL, an array is allocated with 'malloc'; the array is SIZE bytes
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long, unless SIZE == 0, in which case it is as big as
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necessary. */
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# undef getcwd
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# if defined _WIN32 && !defined __CYGWIN__
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# define getcwd _getcwd
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# endif
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char *
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rpl_getcwd (char *buf, size_t size)
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{
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char *ptr;
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char *result;
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/* Handle single size operations. */
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if (buf)
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{
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if (!size)
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{
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errno = EINVAL;
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return NULL;
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}
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return getcwd (buf, size);
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}
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if (size)
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{
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buf = malloc (size);
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if (!buf)
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{
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errno = ENOMEM;
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return NULL;
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}
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result = getcwd (buf, size);
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if (!result)
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{
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int saved_errno = errno;
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free (buf);
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errno = saved_errno;
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}
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return result;
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}
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/* Flexible sizing requested. Avoid over-allocation for the common
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case of a name that fits within a 4k page, minus some space for
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local variables, to be sure we don't skip over a guard page. */
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{
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char tmp[4032];
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size = sizeof tmp;
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ptr = getcwd (tmp, size);
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if (ptr)
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{
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result = strdup (ptr);
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if (!result)
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errno = ENOMEM;
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return result;
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}
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if (errno != ERANGE)
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return NULL;
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}
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/* My what a large directory name we have. */
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do
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{
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size <<= 1;
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ptr = realloc (buf, size);
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if (ptr == NULL)
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{
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free (buf);
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errno = ENOMEM;
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return NULL;
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}
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buf = ptr;
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result = getcwd (buf, size);
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}
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while (!result && errno == ERANGE);
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if (!result)
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{
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int saved_errno = errno;
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free (buf);
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errno = saved_errno;
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}
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else
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{
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/* Here result == buf. */
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/* Shrink result before returning it. */
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size_t actual_size = strlen (result) + 1;
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if (actual_size < size)
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{
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char *shrinked_result = realloc (result, actual_size);
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if (shrinked_result != NULL)
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result = shrinked_result;
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}
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}
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return result;
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}
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#endif
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