On Tue, Jun 22, 2010 at 2:21 PM, Chet Ramey <chet.ra...@case.edu> wrote: > On 6/22/10 12:51 AM, Andres P wrote: >> Bash 4.1 does not set the ERR trap: > > It does, but remember that the ERR trap is only executed under the > circumstances that would cause the shell to exit when set -e is enabled. >
To clarify, I meant that it does not trigger the trap, not that the actual `trap "<eval>" ERR' did not work. > One of the changes between bash-3.2 and bash-4.0 was to make command > substitution understand when it was being executed in a context where > the return value would be ignored, and to ignore any inherited setting > of -e and the ERR trap in those cases. This was part of the big change > in the behavior of set -e in response to the consensus of the Posix > working group, and more directly the result of a bug report. > >> The ERR trap is not executed if the failed command is part of the command >> list immediately following a while or until keyword, part of the test in >> an >> if statement, part of a && or ⎪⎪ list, or if the command's return value is >> being inverted via ! > > The exit status of the command substitution will ultimately be ignored > because it's part of an assignment statement on the LHS of a || list, so > the commands run in the command substitution inherit that state. > > Chet > Thanks, this behaviour seemed strange to me. Although eventually the outer `||' list taking precedence over contained subshells will seem natural in my use cases. It's more consistent. Andres P
