Re: set -u not working as expected

[Chet Ramey]

On 8/1/20 8:47 PM, Lawrence Velázquez wrote:

>> let v+=1 # Line 18, Once line 11 is uncommented, Bash fails here
> 
> I haven't seen the code for arithmetic expansion, but I assume it
> treats v+=1 as morally equivalent to v=${v}+1 (à la C99). Thus there
> *is* an expansion, which fails under set -u. Regardless of the
> particulars, ksh and zsh again agree:

This is indeed what happens in an arithmetic context. It happens with
pre- and post-increment and decrement operators, too.

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/