STARTING LIFELINES AND CREATING DATABASES

You normally start LifeLines with the command: lines database where database is the name of a LifeLines database. If LifeLines finds the database, LifeLines opens the database and takes you to the program's main menu. If the database doesn’t exist, LifeLines asks whether it should create it, and if you answer yes, does so. You may create any number of databases, but only one can be accessed by LifeLines at a time. If you built the LifeLines executable from the source package, the executable may be named lines302 rather than lines. You may either change its name or invoke LifeLines by using the command lines302 instead.

The full command line interface to LifeLines is:
lines [-rwfkam] [database]

The options mean the following:

-r

open database with read only access

-w

open database with writeable access

-f

force open the database – use only in emergency

-a

log dynamic memory operation (for debugging)

The -r option opens the database with read only access. When in this mode LifeLines will not let you modify the database; no other operations are affected. The -w option opens the database with writeable access. If the database cannot be opened with the requested mode LifeLines quits immediately. When you open a database with neither the -r or -w options, LifeLines first tries to open the database with writeable access; if not possible LifeLines then tries to open the database with read-only access; and if this is not possible LifeLines quits. A LifeLines database may be open simultaneously by any number of programs with read-only access; however, if a database is open by a program with writeable access, then it cannot be opened by any other other program.

In rare situations the read/write mode mechanism can fail; when this happens a database may appear unopenable. If this happens use the -f option to force open the database; this will open the database and reset the mode mechanism. This is a dangerous feature; you can use it to open the same database with writeable access more than once; the results are unpredictable and generally disasterous.

If you don’t give the name of a database on the command line, LifeLines will prompt you for it. If you do not use the LLDATABASES shell variable (described later), the name you enter must be the name of a LifeLines database directory expressed using normal UNIX absolute or relative path naming. If you do use the LLDATABASES variable, LifeLines will search for the database in the directories named in the variable; this can be very convenient.