Functions in the C API include the following:
| Function | Description | 
|---|---|
| acu_abend() | Performs the ACUCOBOL-GT signal handling logic | 
| acu_cancel() | Simulates the COBOL CANCEL verb from C | 
| acu_cancel_all() | Simulates the COBOL CANCEL ALL verb from C | 
| acu_cobol() | Allows you to call COBOL programs and control how they are executed | 
| acu_initv() | Initializes the runtime with command-line options | 
| aculongjmp() | Cuts the C and COBOL call stacks to the point recorded in the buffer | 
| acu_register_sub() | Registers a COBOL subroutine that calls a C routine, so you can locate the routines in the calling executable file | 
| acu_runmain() | Starts up a COBOL program that will be treated like the main program of the run unit | 
| acusavenv() | Records information about the state of the C and COBOL call stack | 
| acu_shutdown() | Halts the ACUCOBOL-GT runtime | 
| acu_unload() | Removes a cached program from memory | 
| acu_unload_all() | Removes all cached programs from memory |