5.1 KiB
init.sh developper's reference
1. Getting started
This is a developper's 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. Creating modules will also requires some good knowledge of Bash programming.
2. The aaa_error.sh file
2.1. Functions
2.1.1. 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.
2.1.2. die [--force] <exitcode>
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.
2.1.3. noerror [--noout] <command>
Allow the 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 exit comming with.
If the first parameter is --noout any outputs on standard and error console are disabled. The other parameters is the raw command line to execute.
In any case the function echoes the error code returned by the executed command.
2.2. Other functionnalities
The simple integration of aaa_error.sh file into a script, will change the entire script behaviour regarding errors. 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. Because of this behaviour, the function superseed the internal "errexit" Bash configuration switch, unless the noerror function is used.
- SIGINT: That signal is trigerred when Ctrl + C is pressed by the user. That signal will be interpreted only if the command being executed when the event occurs is a Bash internal. If an executable program receive the signal it will be interpreted with its own mechanisms, generally resulting in an execution error that will trigger an ERR signal as described above. The script will exit after cleanup when that signal is trapped.
- SIGTERM: That signal is typically the result of an external kill of the bash process running the script. The kill signal can comes from the kernel or through the use of a kill command. The script will exit after cleanup.
3. The display.sh file
3.1. Functions
3.1.1. prnt [I|W|E|m] <message>
Print a message with timestamp and header. The header depends on first parameter will be collored and have a fixed length so the messages will always be 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.
3.2. 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
For exemple if you what to wite "ATTENTION: this is a warning!" in red with "ATTENTION:" on yellow background, you should write:
echo -e "${IRed}${On_IYellow}ATTENTION:${DEFAULTBG} this is a warning!${DEFAULTCOL}"
4. The filefct.sh file
4.1. Functions
4.1.1. stdtime
Display date and time based on RFC 3339 standard but slightly modified so it can be used in filename.
That fonction takes no parameters and return its result on standard output.
4.1.2. backupdist <list_of_files_or_dirs>
That fuckyion will provide a backup of any given files or directories given in command line. The backup will be named name.dist-timestamp, where name is the original file or directory name and timestamp the date and time of the backup as retuned by the stdtime function. If a file given in parameter don't exists the function will issue a warning and continue to the next.
The function don't take any other parameters than file and/or directory names.