NAME
realpath —
returns the canonicalized
absolute pathname
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <sys/param.h>
#include <stdlib.h>
char *
realpath(
const
char * restrict pathname,
char * restrict
resolvedname);
DESCRIPTION
The
realpath() function resolves all symbolic links, extra
“/” characters and references to
/./ and
/../ in
pathname, and copies the
resulting absolute pathname into the memory referenced by
resolvedname. The
resolvedname
argument
must refer to a buffer capable of storing at least
MAXPATHLEN
characters, or be
NULL
.
The
realpath() function will resolve both absolute and
relative paths and return the absolute pathname corresponding to
pathname.
RETURN VALUES
If
resolvedname is
NULL
, it will
be allocated and the returned pointer can be deallocated using
free(3). The
realpath() function returns
resolvedname on success. If an error occurs,
realpath() returns
NULL
, and if
resolvedname was not allocated by
realpath(), it will contain the pathname which caused the
problem.
ERRORS
The function
realpath() may fail and set the external variable
errno for any of the errors specified for the library
functions
lstat(2),
readlink(2),
getcwd(3) and
malloc(3).
In addition, the following errors may be reported:
-
-
- [
EINVAL
]
- The value of the pathname argument is
NULL
.
-
-
- [
ELOOP
]
- Too many symbolic links were encountered in translating the
pathname.
-
-
- [
ENAMETOOLONG
]
- The resulting absolute pathname exceeds
MAXPATHLEN
characters.
-
-
- [
ENOENT
]
- The value of the pathname argument is
an empty string; or a symbolic link to an empty string is
encountered.
-
-
- [
ENOTDIR
]
- A component of the path prefix is not a directory.
SEE ALSO
getcwd(3)
STANDARDS
realpath() first appeared in
X/Open
Portability Guide Issue 4, Version 2 (“XPG4.2”)
and is part of
IEEE Std 1003.1-2001
(“POSIX.1”).
HISTORY
The
realpath() function call first appeared in
4.4BSD. In
NetBSD 7.0 the
function was updated to accept a
NULL
pointer for the
resolvedname argument.
BUGS
This implementation of
realpath() differs slightly from the
Solaris implementation. The
4.4BSD version always
returns absolute pathnames, whereas the Solaris implementation will, under
certain circumstances, return a relative
resolvedname
when given a relative
pathname.