Xau

Xau

NAME
SYNOPSIS
DESCRIPTION
SEE ALSO
AUTHOR

---

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 short

address_length, const char *address, unsigned short
number_length, const char *number, unsigned short
name_length, const char *name);

Xauth *XauGetBestAuthByAddr (unsigned short family, unsigned short

address_length, const char *address, unsigned short
number_length, const char *number, int types_length,
char **types, const int *type_lengths);

int XauLockAuth (const char *file_name, int retries, int

timeout, long dead);

	int XauUnlockAuth (const 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

---

---

Opportunity

Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

---

---

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

---

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

---

---

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

---

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.

---

---

Education

Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

---

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.

---