Table of Contents

## Name

Xau library: XauFileName, XauReadAuth, XauLockAuth, XauUnlockAuth, XauWriteAuth, XauDisposeAuth, XauGetAuthByAddr, XauGetBestAuthByAddr - X authority database routines

## Synopsis

#include <X11/Xauth.h>

    typedef struct xauth {
        unsigned short    family;
        unsigned short    address_length;
        char    *address;
        unsigned short    number_length;
        char    *number;
        unsigned short    name_length;
        char    *name;
        unsigned short    data_length;
        char    *data;
    } Xauth;

    char *XauFileName (void); Xauth *XauReadAuth (FILE *auth_file); int XauWriteAuth
    (FILE *auth_file, Xauth *auth); Xauth *XauGetAuthByAddr (unsigned short
    family, unsigned shortaddress_length, char *address, unsigned shortnumber_length,
    char *number);Xauth *XauGetBestAuthByAddr (unsigned short family, unsigned
    shortaddress_length, char *address, unsigned shortnumber_length, char *number,
    int types_length, char**types, int *type_lengths); int XauLockAuth (char
    *file_name, int retries, inttimeout, long dead); int XauUnlockAuth (char
    *file_name); int XauDisposeAuth (Xauth *auth); Description
    XauFileName generates
    the default authorization file name by first checking the XAUTHORITY environment
    variable if set, else it returns $HOME/.Xauthority.  This name is statically
    allocated and should not be freed. XauReadAuth reads the next entry from
    auth_file.  The entry is not statically allocated and should be freed by
    calling XauDisposeAuth.
    XauWriteAuth writes an authorization entry to auth_file.
     It returns 1 on success, 0 on failure.
    XauGetAuthByAddr searches for an
    entry which matches the given network address/display number pair.  The
    entry is not statically allocated and should be freed by calling XauDisposeAuth.

    XauGetBestAuthByAddr is similar to XauGetAuthByAddr, except that a list
    of acceptable authentication methods is specified.  Xau will choose the
    file entry which matches the earliest entry in this list (e.g., the most
    secure authentication method).  The types argument is an array of strings,
    one string for each authentication method.  types_length specifies how many
    elements are in the types array. types_lengths is an array of integers representing
    the length of each string.
    XauLockAuth does the work necessary to synchronously
    update an authorization file.  First it makes two file names, one with ``-c''
    appended to file_name, the other with ``-l'' appended.  If the ``-c'' file already
    exists and is more than dead seconds old, XauLockAuth removes it and the
    associated ``-l'' file.  To prevent possible synchronization troubles with NFS,
    a dead value of zero forces the files to be removed.  XauLockAuth makes
    retries attempts to create and link the file names, pausing timeout seconds
    between each attempt.  XauLockAuth returns a collection of values depending
    on the results:
        LOCK_ERROR    A system error occurred, either a file_name
            which is too long, or an unexpected failure from
            a system call.  errno may prove useful.
        LOCK_TIMEOUT    retries attempts failed
        LOCK_SUCCESS    The lock succeeded.

XauUnlockAuth undoes the work of XauLockAuth by unlinking both the ``-c'' and ``-l'' file names.

XauDisposeAuth frees storage allocated to hold an authorization entry.

## See Also

xauth(1) , xdm(1)

## Author

Keith Packard, MIT X Consortium

Table of Contents

- Name
- Synopsis
- char *XauFileName (void); Xauth *XauReadAuth (FILE *auth_file); int XauWriteAuth (FILE *auth_file, Xauth *auth); Xauth *XauGetAuthByAddr (unsigned short family, unsigned shortaddress_length, char *address, unsigned shortnumber_length, char *number);Xauth *XauGetBestAuthByAddr (unsigned short family, unsigned shortaddress_length, char *address, unsigned shortnumber_length, char *number, int types_length, char**types, int *type_lengths); int XauLockAuth (char *file_name, int retries, inttimeout, long dead); int XauUnlockAuth (char *file_name); int XauDisposeAuth (Xauth *auth); Description
- See Also
- Author