REALPATH(3C) Standard C Library Functions REALPATH(3C)
NAME
realpath - resolve pathname
SYNOPSIS
#include <stdlib.h>
char *realpath(
const char *restrict file_name,
char *restrict resolved_name);
char *canonicalize_file_name(
const char *path);
DESCRIPTION
The
realpath() function derives, from the pathname pointed to by
file_name, an absolute pathname that names the same file, whose
resolution does not involve "
.", "
..", or symbolic links. The generated
pathname is stored as a null-terminated string, up to a maximum of
{
PATH_MAX} bytes (defined in
limits.h(3HEAD)), in the buffer pointed to
by
resolved_name.
The
canonicalize_file_name() function is equivalent to calling
realpath(
path,
NULL). This function is only provided for compatibility.
RETURN VALUES
On successful completion,
realpath() returns a pointer to the resolved
name. Otherwise,
realpath() returns a null pointer and sets
errno to
indicate the error, and the contents of the buffer pointed to by
resolved_name are left in an indeterminate state.
ERRORS
The
realpath() function will fail if:
EACCES Read or search permission was denied for a component of
file_name.
EINVAL Either the
file_name or
resolved_name argument is a null
pointer.
EIO An error occurred while reading from the file system.
ELOOP Too many symbolic links were encountered in resolving
file_name.
ELOOP A loop exists in symbolic links encountered during
resolution of the
file_name argument.
ENAMETOOLONG The
file_name argument is longer than {
PATH_MAX} or a
pathname component is longer than {
NAME_MAX}.
ENOENT A component of
file_name does not name an existing file
or
file_name points to an empty string.
ENOTDIR A component of the path prefix is not a directory.
The
realpath() function may fail if:
ENAMETOOLONG Pathname resolution of a symbolic link produced an
intermediate result whose length exceeds {
PATH_MAX}.
ENOMEM Insufficient storage space is available.
USAGE
The
realpath() function operates on null-terminated strings.
Execute permission is required for all the directories in the given and
the resolved path.
The
realpath() function might fail to return to the current directory if
an error occurs.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+
SEE ALSO
getcwd(3C),
sysconf(3C),
limits.h(3HEAD),
attributes(7),
standards(7) December 20, 2014
REALPATH(3C)