System Function LC

⎕LC - Line Counter

⎕LC is an ISO 13751 standard niladic system function which returns an array of the current line numbers being executed in every current function. Consider the following workspace:

∇ test
[1] 'LC=' ⎕LC
∇

∇ test2
[1] 'Calling Test'
[2] test
∇

So the following commands would produce the following output:

     test
LC= 1 

     test2
Calling Test
LC= 1 2

In the first example where the function test is invoked, only function test is executing so only a scalar - the current line number of test that is being executed - is shown. In the second example where the function test2 is invoked, the APL interpreter program is currently executing line 1 of function test, which was called by line 2 of test2, thus an array of values 1 and 2 is returned.

⎕LC is a niladic system function, you cannot assign a value to it.

System Variables (A value may be assigned to these except for ⎕DM)
⎕ALX	⎕CT	⎕DM	⎕DT	⎕ELX	⎕FC	⎕FEATURE	⎕FPC	⎕IC	⎕IO
⎕LR	⎕LX	⎕PP	⎕PR	⎕PW	⎕RL	⎕SA	⎕WSID
Niladic System Functions (a value cannot be assigned to these)
⎕A	⎕AV	⎕EM	⎕ET	⎕LC	⎕NNAMES	⎕NNUMS	⎕SI	⎕SYSID	⎕SYSVER
⎕T	⎕TC	⎕TCBEL	⎕TCBS	⎕TCESC	⎕TCFF	⎕TCHT	⎕TCLF	⎕TCNL	⎕TCNUL
⎕TS	⎕WA
Monadic or dyadic system functions (a value cannot be assigned to these)
⎕AT	⎕CR	⎕DC	⎕DFT	⎕DL	⎕DR	⎕EA	⎕EC	⎕ERROR	⎕ES
⎕EX	⎕FMT	⎕FX	⎕MF	⎕NAPPEND	⎕NC	⎕NCREATE	⎕NERASE	⎕NINFO	⎕NL
⎕NLOCK	⎕NREAD	⎕NRENAME	⎕NREPLACE	⎕NRESIZE	⎕NSIZE	⎕NTIE	⎕NUNTIE	⎕STOP	⎕TF
⎕TRACE	⎕UCS	⎕VR
Note that quad functions and variables (except for the ⎕A family of functions) are case insensitive