User guide

84 CHAPTER 3. THE LIBRARY
ble to commands such as bcpl, c and setroot via the rootnode fiel ds rtn
rootvar,
rtn
pathvar, rtn hdrsvar and rtn scriptsvar.
When Cintsys (or Cintpos) starts up it requires a valid setting of rtn
pathvar in
order to locate Cintcode modules such as BOOT and BLIB. The default setting of this
field is BCPLPATH (or POSPATH) but can be changed using the -cin argument at startup
as in
cintsys -cin NBCPLPATH
After loading the resident sy st e m control is passed to BOOT which updates the variable
names appropriately for the system being run. It is unlikely that the user wil l want
change the m using setroot alt hough it might be useful to use setroot to see what
names are currentl y being used.
If the value of an environment variable represents a l i s t of directories, they should be
given using Linux style slash ( /) separators and the directories separated by semicolons
(rather than the Linux style colons). This allows colon prefixes such as G: to be used
in, for instance, Windows version of the system. For compatibility with older systems,
colons may be used as an alternative to semicolons when not runni ng under Windows.
When Cintpos starts up the process is similar except the setti ng of rtn pathvar is
POSPATH unless explicitly changed using -cin.
When installing cintsys or cintpos for the first time it is common to fail to set
the environment variables correctly. To help re pai r such mistakes, use the -f option
when calling cintsys or cintpos. This will output a trace of every time any file is
looked up using an environment variable. Even more information is generated if t he
-v argument is also given (or even -vv). Until the system is working correctly it is
recommended that it is started using
cintsys -f
or
cintpos -f -v
3.7 Coroutine examples
This section contai ns examples that use the coroutine mechanism.