On 22/10/2023 00:46, Eduardo Mezêncio wrote:
Greetings,
I would like some help to understand if some behaviors of 'tr' are bugs or just
the intended behavior.
# First case
Consider `echo aaabcc | tr -ds bc a`:
It outputs `a` as expected, because it deletes `b` and `c` and squeezes
`aaa` to a single `a`.
Now consider the same command including `-t`, `echo aaabcc | tr -dst bc a`:
The result is the same, `a`, but I expected it to be `acc`, because `bc`
would be truncated to the lenght of `a`, resulting in `b`, so `b` should be
deleted and `a` squeezed, resulting in `acc`
# Second case
Consider `echo aaabcc | tr -c a _`:
It outputs `aaa___` as expected
Now the same with -t, `echo aaabcc | tr -ct a _`:
I expected it to output the same thing, because `-t` should make no
difference in this case, but it outputs `aaabcc`, same as the input
-t is there mainly to provide compat with System V tr operation.
The full manual also states that -t is only significant with translation,
which explains the first case at least.
In the second case it depends on the order of operations,
but I expect this is compat with System V operation
(which I don't have access to to confirm at present).
cheers,
Pádraig
