TACL Reference Manual

Built-In Functions and Variables
HP NonStop TACL Reference Manual—429513-018
9-131
#DELTA Built-In Function
file. If you use the Y command on a closed file, it loads the value zero into the X
register.
#DELTA does all file I/O in PLAIN mode.
The Z Command
The Z command loads the X register with the size of the currently used portion of the
buffer (in characters). You can use the Z command as a pointer to the end of the
buffer. For example, the commands Z K delete the characters from the current position
to the end of the buffer.
The $ Command
The dollar sign command clears both the X and Y registers.
You may want to use the dollar sign command before a command that can behave
differently depending on whether there are values in the X or Y registers.
The end-of-line following a line of #DELTA commands also clears the X and Y
registers.
The , Command
The comma command moves the contents of the X register to the Y register and clears
the X register. You can then load a second value into the X register. For example:
#DELTA 73> 8 =
#DELTA 73> EOF!
8
#DELTA 74> 8, =
#DELTA 74> EOF!
8,0
#DELTA 75> 8,40 =
#DELTA 75> EOF!
8,40
#DELTA 76>
If you enter another comma and another new X register value, the first Y register value
is lost.
The . Command
The period command loads the current pointer position into the X register.
The = Command
The equal sign command displays the contents of the X and Y registers on your
current output device. The = command is useful for debugging macros. If you are not
sure what value is in the X and Y registers before a command is executed, insert the
equal sign before that command. (Remember to remove the equal sign when you have
finished debugging; the = command destroys the contents of the X and Y registers.)