Resolver processing of the setup file when the resolver is started

During resolver address space initialization, the resolver parses the entire resolver setup file using the following rules:

When a setup statement has a syntax error, the resolver generates a warning message to the console and the setup statement is skipped.
When the resolver does not recognize a setup statement, the resolver generates a warning message to the console and the setup statement is skipped.
When the resolver parses multiple instances of the same setup statement that have no syntax errors, the resolver uses the setting on the last instance that is parsed.
When the resolver completes parsing of the resolver setup file and did not parse any instances of a resolver setup statement that are syntactically correct, the resolver takes the default value for that setup statement
When a resolver setup statement (for instance, GLOBALTCPIPDATA) specifies an MVS™ data set name or a z/OS® UNIX file name that the resolver cannot open or access, the resolver considers that to be a syntax error.
When there are multiple instances of a setup statement that have no syntax errors and that specify an MVS data set name or z/OS UNIX file name, the resolver attempts to open or access the data set or file specified on only the last instance that is parsed. If the resolver cannot open or access this data set or file, the resolver proceeds as if this setup statement had not been specified.
When the resolver cannot open the resolver setup file, the resolver uses all the default settings for the configuration.
When the resolver setup file is the wrong format, the resolver uses all the default settings for the configuration.
If the resolver generates any warning messages due to syntax errors or unrecognized statements during resolver address space initialization, the resolver issues message EZD2038I at the conclusion of resolver address space initialization.
If the resolver does not generate any warning messages during resolver address space initialization, the resolver issues message EZZ9291I when the address space is initialized.

Results:

Consider a resolver setup file that contains the following statements:
```
CACHE
NOCACHE
CACH
```
The resolver issues a warning message for the line specifying the value CACH and ignores the value. Because NOCACHE was parsed after the valid statement CACHE, the resolver uses the NOCACHE setup statement and caching is disabled for this system.
Consider a resolver setup file that contains the following statements:
```
GLOBALTCPIPDATA(/etc/tcpip.data)
GLOBALTCPIPDATA(/etc/newer.tcpip.data)
DEFAULTTCPIPDATA(/etc/default.tcpip.data)
```
Each of these statements is syntactically correct, so the resolver uses the value coded on the last GLOBALTCPIPDATA statement as the name of the global TCPIP.DATA file. The resolver attempts to access the files /etc/newer.tcpip.data and /etc/default.tcpip.data. If the file /etc/newer.tcpip.data does not exist, the resolver generates a warning message and proceeds as if no global file were specified; the resolver does not attempt to use /etc/tcpip.data as the global TCPIP.DATA file. If /etc/default.tcpip.data does not exist, the resolver generates a warning message and proceeds as if no default file were specified.