Re: How does {x..y} supposed to work?

[Lawrence Velázquez]

On Thu, May 13, 2021, at 12:02 PM, Peng Yu wrote:
> According to the manpage, x and y can be single characters. "the
> expression expands to each character lexicographically between x and
> y, inclusive".
> 
> So my understanding of the behavior of {x..y} should be that `echo
> {%..a}` print all the ascii letters between "%" and "a" including "%"
> and "a", but it doesn't do so. Do I interpret the manual incorrectly?
> Or the bash implementation does not match the manpage completely?

The code explicitly wants alphabetics.  The manual could probably
stand to be a little more specific than just "characters".

https://git.savannah.gnu.org/cgit/bash.git/tree/braces.c?id=ce23728#n497

  /* Now figure out whether LHS and RHS are integers or letters.  Both
     sides have to match. */
  lhs_t = (legal_number (lhs, &tl)) ? ST_INT :
                ((ISALPHA (lhs[0]) && lhs[1] == 0) ?  ST_CHAR : ST_BAD);


-- 
vq