Library lists

The library list for a job indicates which libraries are to be searched and the order in which they are to be searched.

When a program specifies an object, the object can be specified with a qualified name, which includes both the object name and the library name. Or, the library for the object can be specified as *LIBL (library list). The libraries on the library list are searched, in order, until the object is found.

Table 1 summarizes the parts of the library list and how they are built during a job. The sections that follow discuss the risks and protection measures for library lists.

Table 1. Parts of the library list. The library list is searched in this sequence:
Part	How it is built
System Portion 15 entries	Initially built using the QSYSLIBL system value. Can be changed during a job with the CHGSYSLIBL command.
Product Library Portion 2 entries	Initially blank. A library is added to the product library portion of the library list when a command or menu runs that was created with a library in the PRDLIB parameter. The library remains in the product library portion of the library list until the command or menu ends.
Current Library 1 entry	Specified in the user profile or on the Sign On display. Can be changed when a command or menu runs that specifies a library for the CURLIB parameter. Can be changed during the job with the CHGCURLIB command.
User Portion 250 entries	Initially built using the initial library list from the user’s job description. If the job description specifies *SYSVAL, the QUSRLIBL system value is used. During a job, the user portion of the library list can be changed with the ADDLIBLE, RMVLIBLE, CHGLIBL, and EDTLIBL commands.