Editing Object (IBM i) (section)

==Libraries==

A '''library''' (*LIB) on [[IBM i]] is an object that is used as a system [[directory service|directory]] to keep track of other objects. Objects are not stored inside libraries, but rather libraries are used as namespaces for objects. Libraries are a "system" object, and therefore only one instance of any given Library "name" is possible. They're made to appear as if they're stored in the QSYS library.

===Standard libraries===

Generally speaking all libraries created by IBM for use by the [[IBM i|operating system]] begin with the letter 'Q'.  

IBM Standard Libraries:
*QSYS - System Parent Library
*QSYS2 - System Library for CPI's(Characters Per Inch)
*QHLPSYS - Online Documentation Library for Users
*QTCP - TCP Connectivity Utilities
*QAFP - Advanced Function Printing
*QGPL - General Purpose Library
*QTEMP - Job specific temporary Library (deleted when the job ends)

===Library List===

A library list (<code>*LIBL</code>) is an object which specifies a default set of locations to look for an object (similar to the [[PATH (variable)|PATH]] mechanism of other operating systems). This object doesn't exist on its own and is always associated with another object like a job or a job description (<code>*JOBD</code>). Some job descriptions specify the special value <code>*SYSVAL</code> which means that the library list can be found in the system value <code>QUSRLIBL</code>. As of [[OS/400]] V5R1, the user portion of the Library List can contain up to 250 library names. Prior to that it could only have 25 libraries.

A job's library list consists of four sections:
* '''System portion''': Always at the top and contains system libraries like <code>QSYS</code>, <code>QHLPSYS</code>, <code>QUSRSYS</code>, etc. The system portion can hold up to 15 library names. The default contents of the system portion are specified in the <code>QSYSLIBL</code> system value. The contents of the system portion can be changed for the current job to differ from <code>QSYSLIBL</code> by using the <code>CHGSYSLIBL</code> [[Control Language|command]]. 
* '''Product portion''': When a CL command is executed that specifies a production [[AS/400 library|library]], that library will be added to the product portion of the library list for the duration of the command. It follows the system portion and the O/S will maintain up to two libraries in it. 
* '''Current library''': Is a special [[AS/400 library|library]] associated with a user profile and there can only be one in the list at a time. This library is useful for programmers to have their personal library at the top of the list regardless of what the user portion is changed to. It can be changed locally using the <code>[http://as400i.com/2018/12/08/current-library-chgcurlib CHGCURLIB]</code> command. To change it for the user on all future jobs use the <code>CHGUSRPRF</code> command. 
* '''User portion''': The last part of the library list that contains all of the application [[AS/400 library|libraries]]. The list is normally assigned to the job from the job description but for batch jobs this can be overridden using the <code>SBMJOB</code> command's <code>INLLIBL</code> parameter. A job's library list can be changed locally with the <code>EDTLIBL</code>(Edit Library List), <code>CHGLIBL</code>(Change Library List), <code>ADDLIBLE</code>(Add Library List Entry), and <code>RMVLIBLE</code>(Remove Library List Entry) command.