B Programmer Interface

When the first GNS routine is called, the GNS database files are opened. It is therefore not necessary to call GNS_START unless you want to verify that the database can be opened before it is accessed. GNS_STOP will close the database but can be omitted in stand alone programs where image exit will close the database.

Most character output arguments are accompanied by an integer length argument; when the requested information is not available, the length argument is returned as zero. This length must therefore always be checked before being used to access a sub-string of the character argument. The symbolic constants representing the maximum lengths of the various character arguments are defined in a FORTRAN include file that can be referenced by the name GNS_PAR.

All routines that are specific to GKS have names ending in the letter “G” and routines specific to IDI have names ending in the letter “I”.

B.1 Summary of GNS calls

GNS_GTN ( NAME, LNAME, STATUS)
Get terminal name.

GNS_GWNG ( FILTER, ICNTX, NAME, DESCR, LD, STATUS)
Get next GKS workstation name.

GNS_GWNI ( FILTER, ICNTX, NAME, DESCR, LD, STATUS)
Get next IDI workstation name.

GNS_IANG ( NAME, AGINAM, STATUS)
Inquire AGI name of GKS workstation.

GNS_IANI ( NAME, AGINAM, STATUS)
Inquire AGI name of IDI workstation.

GNS_IDNG ( IWKID, NAME, LNAME, STATUS)
Inquire device name of GKS workstation.

GNS_IETG ( IWKID, ERTXT, LTXT, STATUS)
Inquire string to erase text screen.

GNS_IGAG ( AGINAM, NAME, STATUS)
Inquire GKS workstation name from AGI name.

GNS_IIAI ( AGINAM, NAME, STATUS)
Inquire IDI workstation name from AGI name.

GNS_IONG ( IWKID, NAME, LNAME, STATUS)
Inquire overlay device name of GKS workstation

GNS_ITWCG ( IWKTYP, CHAR, VALUE, STATUS)
Inquire a workstation characteristic from its type.

GNS_IWCG ( IWKID, CHAR, VALUE, STATUS)
Inquire a workstation characteristic.

GNS_IWSG ( IWKID, SCALE, STATUS)
Inquire workstation scale.

GNS_START ( PKG, STATUS)
Start the GNS system for the specified package.

GNS_STOP ( PKG, STATUS)
Stop the GNS system for the specified package.

GNS_TNDG ( NAME, DEVICE, IWKTYP, ICONID, STATUS)
Translate a name and device to a GKS device specification.

GNS_TNG ( NAME, IWKTYP, ICONID, STATUS)
Translate a name to a GKS device specification.

GNS_TNI ( NAME, TYPE, DEVICE, STATUS)
Translate a name to a IDI device specification.