vaab/kal-shlib-core

kalysto shell libs core include mecanism

What is kal-shlib ?

These shell components contains the core libraries that ease a lot of common tasks encountered when scripting in bash.

The shell libs are divided into several sub-packages providing code for various needs. An exception is kal-shlib-core which contains the central library inclusion mecanism. As a consequence, it is a dependence of all kal-shlib-* packages.

What is kal-shlib-core ?

This package only provide the library inclusion mecanism. Please note that it provides also the shlib executable that allows to inline bash code from the library into any shell script using shlib facilities. This allows you to use the shell script on system without the kal-shlib-core package installed.

You can compare this with statically compiled C code, and dynamically linked library. shlib allows you to go back and forth between these 2 states.

Do I need shlibs ?

If you take time shell-scripting, this might be of interest, some function have actually saved me lot of time.

If you have found an utility for other component of the kal packages, you can save place by making all binaries dynamically linked to these libraries. This is especially useful if you have installed more than one kal package.

I use shlib executable for many of my other publicly distributed shell script program.

Where can I find docs ?

Sorry, there are very few docs at the moment. Best of all is to look at libraries source code.

How can I install it ?

Consider this release as alpha software. Use at your own risk. It may or may not upgrade to a more user friendly version in future, depending on my spare time.

From source

You might have to consider running ./autogen.sh if you got source from git.

If you got the source code thanks to downloading the tar.gz, running ./autogen.sh shouldn't be necessary.

This package support GNU install quite well so a simple:

# ./configure && make && make install

Should work (and has been tested and is currently used).

Note: you can specify a --prefix=/your/location

From debian package

This method works with any Debian distrib or Ubuntu version and derivatives.

A debian package repository is available at:

deb http://deb.kalysto.org no-dist kal-alpha

You should include this repository to your apt system and then:

# apt-get update && apt-get install kal-shlib-core

What do this package contains ?

• directory $prefix/lib/shlib/ where library will be loaded
• an executable shlib installed in $prefix/bin
• an executable bash-shlib installed in $prefix/bin
• a config file shlib installed in $prefix/etc

The debian package version will install to these location (and $prefix is set to /)

How can I use the libraries in one of my scripts ?

You just have to source /etc/shlib in your bash script or use bash-shlib as a replacement shebang interpreter. Either of these this will give you access to an include function allowing you to source any library found in /usr/lib/shlib/lib*.sh.

So you need some libraries in /usr/lib/shlib/lib*.sh to go forward, you can write them or install some provided like kal-shlib-common and others...

Example:

#!/bin/bash

. /etc/shlib

include common

die "Argl!"      ## function 'die' comes from 'common'

These can be installed manually, or thanks to debian packages of various kal-shlib-*.

As an alternative, you can use the shebang loading bash-shlib that will then source for you the /etc/shlib. This is shorter, example:

#!/usr/bin/bash-shlib

include common

die "Argl!"

Special autoloaded code ?

With version 0.5, you can now put source code into /usr/lib/shlib/autoload/*.sh, and they will be autoloaded to any shlib using code.

DO NOT ABUSE of this. This is used mainly to add new features to shlib code, from external package, as shell decorators.

How to use the executable linker shld ?

Depending on the method you use to load the shell lib (aka, using the bash-shlib interpreter or sourcing /etc/shlib).

Using the sourcing method, these lines of code should be inserted at the beginning of your shell script, before any other shell code, but after the shebang:

#!- shlib loader
. /etc/shlib  ## shlib call
#!-

Note that there two #!- at the beginning of line. You can put any comment after. These 2 lines will mark the beginning and ending of the shlib call.

Using the bash-shlib interpreter, you have nothing special to do.

Then, for both method, what follows applies:

# shlib d <filename>

will erase and write a dynamical version of the shlib caller. This means that your shell script will look for the libraries at each call.

# shlib s <filename>

will erase and write a statical version of the shlib caller. It makes a snapshot of your current libraries and feeds it in your script.