⎕TC is a deprecated feature and is replaced by ⎕UCS (see note).
⎕TC is a simple three element vector. If ⎕ML<3 this is ordered as follows:
| ⎕TC[1] | Backspace |
| ⎕TC[2] | Linefeed |
| ⎕TC[3] | Newline |
Note that ⎕TC≡⎕AV[1+⍳3] for ⎕ML<3 .
If ⎕ML≥3the order of the elements of ⎕TC is instead compatible with IBM's APL2:
| ⎕TC[1] | Backspace |
| ⎕TC[2] | Newline |
| ⎕TC[3] | Linefeed |
Elements of ⎕TC beyond 3 are not defined but are reserved.
With the introduction of ⎕UCS in Version 12.0, the use of ⎕TC is discouraged and it is strongly recommended that you generate control characters using ⎕UCS instead. This recommendation holds true even if you continue to use the Classic Edition.
| Control Character | Old | New |
|---|---|---|
| Backspace | ⎕TC[1] | ⎕UCS 8 |
| Linefeed | ⎕TC[2] (⎕ML<3) ⎕TC[3] (⎕ML≥3) |
⎕UCS 10 |
| Newline | ⎕TC[3] (⎕ML<3) ⎕TC[2] (⎕ML≥3) |
⎕UCS 13 |