beginning of programmer's reference

doc/dev.md

@@ -1,7 +1,7 @@
 # init.sh developper's reference
 
 ## Getting started
-This is a programmer reference. It's not intended to be a manual, be a reference
+This is a programmer reference. It's not intended to be a manual, but a reference
 for all internal functions, so you can easily build your own modules. This
 suppose you already read the [Readme file](../README.md). Creating modules
 will also requires some good knowledge of Bash programming.
@@ -9,4 +9,70 @@ will also requires some good knowledge of Bash programming.
 ## The aaa_error.sh file
 ### Functions
 #### check_root
+Check if user is root. If user is not root, script execution is interupted and
+exit with error.
+
+This function have no parameter.
+
+If the variable NO_ROOT_CHECK is set to true the function always exit without
+error and no check is done.
+
+#### die
+Trigger an error, print a backtrace and exit the script, unless KEEPGOING
+variable is set to true. In that situation we just display a warning.
+
+If the parameter --force is given, we exit even if the KEEPGOING variable is set
+to true.
+
+#### noerror
+Allow te execution of a command bypassing the error management system. The purpose
+is to allow execution of test returning normally a non zero value without
+triggering an error and the following exit.
+
+If the first parameter is --noout all the outputs are disabled. The other
+parameters are the raw command line to execute.
+
+The function echoes the error code returned by the executed command.
+
+### Other functionnalities
+The simple integration of aaa_error.sh file into a script, will change the script
+behaviour. The following Bash signals will be trapped:
+ - **ERR**: The ERR signal is triggered every time Bash encounter an error or if
+a command return a non zero value. The function called on that signal will stop
+execution of the script displaying an error message with error code and a backtrace
+to help identify the error origin.
+ - **SIGINT**: That signal is trigerred when Ctrl + C is pressed by the user. That
+signal will be interpreted only if the command is a Bash internal. If an executable
+receive the signal it will be interpreted with the own executable mechanisms. We
+will exit after cleanup.
+ - **SIGTERM**: That signal is typically the result of an external kill of the bash
+process running the script. We will exit after cleanup.
+
+## The display.sh file
+### Functions
+#### prnt
+Print a message with timestamp and header. The header depends on first parameter
+will be collored and have a fixed lenght so text is always alligned.
+
+The first parameter is the header type, having those possible values:
+ - **I**: Display an informative message in green
+ - **W**: Display a warning in yellow
+ - **E**: Display an error in red
+ - **m**: Display a message without header but alligned
+ - Anything else will be treated as the message and will loose alignment.
+ 
+Second parameter is the message to display.
+ 
+### Other functionnalities
+Using that script will declare many easy to remember variables containing Bash
+color codes :
+
+ - Standard codes depending on your environment: DEFAULTFG, DEFAULTBG, DEFAULTCOL=${DEFAULTBG}${DEFAULTFG}
+ - Regular Colors: Black, Red, Green, Yellow, Blue, Purple, Cyan, White
+ - Bold: BBlack, BRed, BGreen, BYellow, BBlue, BPurple, BCyan, BWhite
+ - Underline: UBlack, URed, UGreen, UYellow, UBlue, UPurple, UCyan, UWhite
+ - Background: On_Black, On_Red, On_Green, On_Yellow, On_Blue, On_Purple, On_Cyan, On_White
+ - High Intensity:  IBlack, IRed, IGreen, IYellow, IBlue, IPurple, ICyan, IWhite
+ - Bold High Intensity:  BIBlack, BIRed, BIGreen, BIYellow, BIBlue, BIPurple, BICyan, BIWhite
+ - High Intensity backgrounds: On_IBlack, On_IRed, On_IGreen, On_IYellow, On_IBlue, On_IPurple, On_ICyan, On_IWhite