Add Password authentication to Apache Server

This is to add password authentication to Apache web server. The password file used is the Linux password file. By doing this, apache authentication is linked to linux authentication.

Of course because web authentication password is passed in clear, SSL/HTTPS should be used if security is of any concern.

download and install the Mod_Auth_External module and the pwauth utility.

simply follow the instructions in INSTALL file.

One thing is to make sure the user id in pwauth config.h file is correct (corresponding to the "apache" user id).

SWFTOOLS Examples

Some good examples of swfc code, including a viewer for pdf

http://technoargia.free.fr/swftools/examples/viewer_home/viewer_home.html

Makefile Variables

A summary of the automatic variables. See Automatic Variables, for full information (taken from GNU Make Manual).

$@

The file name of the target.

$%

The target member name, when the target is an archive member.

$<

The name of the first prerequisite.

$?

The names of all the prerequisites that are newer than the target, with spaces between them. For prerequisites which are archive members, only the member named is used (see Archives).

$^

$+

The names of all the prerequisites, with spaces between them. For prerequisites which are archive members, only the member named is used (see Archives). The value of $^ omits duplicate prerequisites, while $+ retains them and preserves their order.

$*

The stem with which an implicit rule matches (see How Patterns Match).

BASH programming reference card

Appendix B. Reference Cards

The following reference cards provide a useful summary of certain scripting concepts. The foregoing text treats these matters in more depth, as well as giving usage examples.

Table B-1. Special Shell Variables

Variable	Meaning
$0	Filename of script
$1	Positional parameter #1
$2 - $9	Positional parameters #2 - #9
${10}	Positional parameter #10
$#	Number of positional parameters
"$*"	All the positional parameters (as a single word) *
"$@"	All the positional parameters (as separate strings)
${#*}	Number of command line parameters passed to script
${#@}	Number of command line parameters passed to script
$?	Return value
$$	Process ID (PID) of script
$-	Flags passed to script (using set)
$_	Last argument of previous command
$!	Process ID (PID) of last job run in background

* Must be quoted, otherwise it defaults to "$@".

Table B-2. TEST Operators: Binary Comparison

Operator	Meaning	-----	Operator	Meaning
Arithmetic Comparison			String Comparison
-eq	Equal to		=	Equal to
			==	Equal to
-ne	Not equal to		!=	Not equal to
-lt	Less than		\<	Less than (ASCII) *
-le	Less than or equal to
-gt	Greater than		\>	Greater than (ASCII) *
-ge	Greater than or equal to
			-z	String is empty
			-n	String is not empty
Arithmetic Comparison	within double parentheses (( ... ))
>	Greater than
>=	Greater than or equal to
<	Less than
<=	Less than or equal to

* If within a double-bracket [[ ... ]] test construct, then no escape \ is needed.

Table B-3. TEST Operators: Files

Operator	Tests Whether	-----	Operator	Tests Whether
-e	File exists		-s	File is not zero size
-f	File is a regular file
-d	File is a directory		-r	File has read permission
-h	File is a symbolic link		-w	File has write permission
-L	File is a symbolic link		-x	File has execute permission
-b	File is a block device
-c	File is a character device		-g	sgid flag set
-p	File is a pipe		-u	suid flag set
-S	File is a socket		-k	"sticky bit" set
-t	File is associated with a terminal
-N	File modified since it was last read		F1 -nt F2	File F1 is newer than F2 *
-O	You own the file		F1 -ot F2	File F1 is older than F2 *
-G	Group id of file same as yours		F1 -ef F2	Files F1 and F2 are hard links to the same file *
!	"NOT" (reverses sense of above tests)

* Binary operator (requires two operands).

Table B-4. Parameter Substitution and Expansion

Expression	Meaning
${var}	Value of var, same as $var
${var-DEFAULT}	If var not set, evaluate expression as $DEFAULT *
${var:-DEFAULT}	If var not set or is empty, evaluate expression as $DEFAULT *
${var=DEFAULT}	If var not set, evaluate expression as $DEFAULT *
${var:=DEFAULT}	If var not set, evaluate expression as $DEFAULT *
${var+OTHER}	If var set, evaluate expression as $OTHER, otherwise as null string
${var:+OTHER}	If var set, evaluate expression as $OTHER, otherwise as null string
${var?ERR_MSG}	If var not set, print $ERR_MSG *
${var:?ERR_MSG}	If var not set, print $ERR_MSG *
${!varprefix*}	Matches all previously declared variables beginning with varprefix
${!varprefix@}	Matches all previously declared variables beginning with varprefix

* Of course if var is set, evaluate the expression as $var.

Table B-5. String Operations

Expression	Meaning
${#string}	Length of $string
${string:position}	Extract substring from $string at $position
${string:position:length}	Extract $length characters substring from $string at $position
${string#substring}	Strip shortest match of $substring from front of $string
${string##substring}	Strip longest match of $substring from front of $string
${string%substring}	Strip shortest match of $substring from back of $string
${string%%substring}	Strip longest match of $substring from back of $string
${string/substring/replacement}	Replace first match of $substring with $replacement
${string//substring/replacement}	Replace all matches of $substring with $replacement
${string/#substring/replacement}	If $substring matches front end of $string, substitute $replacement for $substring
${string/%substring/replacement}	If $substring matches back end of $string, substitute $replacement for $substring
expr match "$string" '$substring'	Length of matching $substring* at beginning of $string
expr "$string" : '$substring'	Length of matching $substring* at beginning of $string
expr index "$string" $substring	Numerical position in $string of first character in $substring that matches
expr substr $string $position $length	Extract $length characters from $string starting at $position
expr match "$string" '\($substring\)'	Extract $substring* at beginning of $string
expr "$string" : '\($substring\)'	Extract $substring* at beginning of $string
expr match "$string" '.*\($substring\)'	Extract $substring* at end of $string
expr "$string" : '.*\($substring\)'	Extract $substring* at end of $string

* Where $substring is a regular expression.

Table B-6. Miscellaneous Constructs

Expression	Interpretation
Brackets
if [ CONDITION ]	Test construct
if [[ CONDITION ]]	Extended test construct
Array[1]=element1	Array initialization
[a-z]	Range of characters within a Regular Expression
Curly Brackets
${variable}	Parameter substitution
${!variable}	Indirect variable reference
{ command1; command2; . . . commandN; }	Block of code
{string1,string2,string3,...}	Brace expansion
{a..z}	Extended brace expansion
{}	Text replacement, after find and xargs
Parentheses
( command1; command2 )	Command group executed within a subshell
Array=(element1 element2 element3)	Array initialization
result=$(COMMAND)	Execute command in subshell and assign result to variable
>(COMMAND)	Process substitution
<(COMMAND)	Process substitution
Double Parentheses
(( var = 78 ))	Integer arithmetic
var=$(( 20 + 5 ))	Integer arithmetic, with variable assignment
(( var++ ))	C-style variable increment
(( var-- ))	C-style variable decrement
(( var0 = var1<98?9:21>	C-style trinary operation
Quoting
"$variable"	"Weak" quoting
'string'	"Strong" quoting
Back Quotes
result=`COMMAND`	Execute command in subshell and assign result to variable

From http://tldp.org/LDP/abs/html/refcards.html#AEN20071