On 2023-01-11 06:44, Chet Ramey wrote:
On 1/10/23 9:36 PM, Quinn Grier wrote:
In the documentation for set -e, the Bash manual says that errexit is
suspended in all but the last command of a pipeline:
The shell does not exit if the command that fails is part of
[...] any command in a pipeline but the last
I'm not sure why you included the `part of' in your quote, since it clearly
applies to the text following it: "part of the command list immediately
following as while or until keyword, part of the test following ..."
I agree, my quotation of that documentation is wrong, as "part of" does
not apply to "any command in a pipeline". However, I still think my
example script shows something fishy.
Here's another example script that might help show what I mean. This one
goes through all of the apparent contexts where set -e is ignored:
# Without set -e, all "echo" commands run.
while (false; echo -n 1); do break; done # Outputs 1
until (false; echo -n 2); do break; done # Outputs 2
if (false; echo -n 3); then :; fi # Outputs 3
(false; echo -n 4) && : # Outputs 4
(false; echo -n 5) || : # Outputs 5
(false; echo -n 6) | cat # Outputs 6
! (false; echo -n 7) # Outputs 7
echo
# With set -e, all "echo" commands should still run despite
# the fact that "false" would normally cause an exit before
# "echo", as these are all contexts where set -e is ignored.
set -e
while (false; echo -n 1); do break; done # Outputs 1
until (false; echo -n 2); do break; done # Outputs 2
if (false; echo -n 3); then :; fi # Outputs 3
(false; echo -n 4) && : # Outputs 4
(false; echo -n 5) || : # Outputs 5
(false; echo -n 6) | cat # No output (!)
! (false; echo -n 7) # Outputs 7
echo
The output of this script is:
1234567
123457
Why is "6" missing from the second line?
