realpath(3C)

NAME

     realpath - resolve pathname

SYNOPSIS

     #include <stdlib.h>

     char *realpath(const char *file_name, char *resolved_name);

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  sym-
     bolic  links.  The generated pathname, using PATH_MAX bytes,
     is stored in the buffer pointed to by resolved_name.

     The realpath() function can handle both relative  and  abso-
     lute  path  names.  For absolute path names and the relative
     names whose resolved name  cannot  be  expressed  relatively
     (for  example,  ../../reldir), it returns the resolved abso-
     lute name. For the other relative path names, it returns the
     resolved relative name.

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  con-
     tents  of  the  buffer pointed to by resolved_name are unde-
     fined.

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
           path.

     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.

     One should have execute permission on all the directories in
     the given and the resolved path.

     The realpath() function may fail to return  to  the  current
     directory if an error occurs.

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|

SEE ALSO

     getcwd(3C), sysconf(3C), attributes(5)