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sortix--sortix/libc/realpath.cpp
Jonas 'Sortie' Termansen 9d3937fe9e Add realpath(3).
2013-12-17 14:30:28 +01:00

57 lines
1.9 KiB
C++

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2013.
This file is part of the Sortix C Library.
The Sortix C Library is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
The Sortix C Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
realpath.cpp
Return the canonicalized filename.
*******************************************************************************/
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
char* realpath(const char* restrict path, char* restrict resolved_path)
{
char* ret_path = canonicalize_file_name(path);
if ( !ret_path )
return NULL;
if ( !resolved_path )
return ret_path;
#ifdef PATH_MAX
if ( PATH_MAX < strlen(ret_path) + 1 )
return errno = ENAMETOOLONG, (char*) NULL;
strcpy(resolved_path, ret_path);
free(ret_path);
return resolved_path;
#else
if ( !isatty(2) )
dup2(open("/dev/tty", O_WRONLY), 2);
fprintf(stderr, "%s:%u: %s(\"%s\", %p) = \"%s\": "
"This platform doesn't have PATH_MAX and the second argument "
"wasn't NULL - You cannot reliably allocate a sufficiently large "
"buffer and the POSIX standard specifies this as undefined "
"behavior, aborting.\n", __FILE__, __LINE__, __func__, path,
resolved_path, ret_path);
abort();
#endif
}