To invoke a GT.M function, the calling routine must specify the function in the source program, using the syntax of the source language. The reference manual for the programming language you are using provides details about the syntax.

GT.M supports calls to DAL functions from external routines that were invoked from M.

This chapter provides examples in VMS C, including one comprehensive example at the end of the chapter. The examples use an ampersand (&), which in C represents the address of the specified variable, (e.g., &stuff is the address of the variable "stuff").