API Usage

Path: /src/index.coffee compiled to /lib/index.js

This module is used as API in all alinex based apps. It will help setting it up.

A function to bring a common logo to all alinex cli interfaces using ASCII art can be made. The logo is designed to be output on console view.

CoffeeScript Code
alinex = require 'alinex-core'
logo = alinex.logo 'Development Helper'
console.log logo

You have the ability to change the logo to another included one by using an environment setting of: LOGO=<name>

The resulting string is colorized using ascii escape code and may look like:

Logo

logo()

Usage:logo(title)

Parameter
  • title - String optional application title (default: Application)
Return
String logo like shown above to be printed on console

Error management

The following code will setup handler for SIGNAL handling and also give you handy method for exit the program with code and message.

CoffeeScript Code
alinex = require 'alinex-core'
alinex.initExit()
alinex.exit 1, new Error "Something went wrong"

This will:

  • output the error
  • output a possible err.description property
  • exit the process with the given code
  • auto set the code if possible

The alinex tools are based on the bash exit codes 0, 1 and 124-143. In addition the codes 3-6 are used for NodeJS system codes and some alinex codes are set in the range 16-120 like:

Code Description
0 OK - no error
1 General error which should not occur
2 Command parameter problem
3 File system access problem
4 Network problems
5 Service or system access problem
6 No such service or address
124 command times out
125 if a command itself fails
126 Command invoked cannot execute
127 “command not found”
128 Invalid argument to exit
129 SIGHUP (Signal 1)
130 SIGINT like through Ctrl + C (Signal 2)
131 SIGQUIT (Signal 3)
134 SIGABRT or SIGIOT (Signal 6)
143 SIGTERM (Signal 15)
255 Exit status out of range

You can find all possible codes for bash and Linux in the developer guide.

This handler may also autodetect the exit code from the given error. To use this call it without an exit code:

CoffeeScript Code
alinex = require 'alinex-core'
alinex.initExit()
err = new Error "Wrong parameter"
err.exit = 2
alinex.exit err

The exit code will be taken from:

  • the err.exit field
  • from the err.code name (autodetect for node errors)

This procedure gives you the possibility to define the exit code then the error occurs but throw it first and decide later on other position if you want to give it to the exit handler.

initExit()

Initialize signal handler to exit on common interrupt signals.

Return
function(<Integer>, <String>) returns theexit() function to be used.

exit()

This method will exit processing immediately and return to the OS with an error code.

Usage:exit(code, err)

Parameter
  • code - integer optional error code number (default: autodetect)
  • err - Error optional error message

This will output a message on STDERR before exiting with the defined or detected exit code.