Re: [Bug-ed] GNU ed 1.11-rc1 released

[Andrew L. Moore]

Antonio Diaz Diaz wrote:

Changes in this version:

* The "z" command has been fixed. ("zN" printed N + 1 lines). This bug was present since at least ed-0.2.

This bug exists in the *BSD ed’s as well, unfortunately.

Though documented otherwise in the ed man page (ed.1), the intent of the command `zN’ is to set the window size to N, which is persistent (unlike with ex(vim)).  If the command prompt is counted as one line, then it should really display only N - 1 lines from the buffer.  In your current implementation (1.11rc1), on an N line display, only N - 2 lines of the buffer are displayed - the top line being the previous command.  To verify this:

$ ed

r !seq 100

!           <<<<  Per POSIX, bang should be printed on return from shell command.

292

1z

On the other hand, you’re in good company: ex(vim) exhibits this (mis)behavior too.  And since the

command `z' is explicitly omitted from SUSv4, you pretty much have a free hand to define the behavior as you wish.  Then again, ex(vim) properly documents the command `zN' as setting the window height, indicating that the current behavior in ex(vim) is probably a bug...

-AM