Re: reset a trap upon use

[Chet Ramey]

On 11/24/23 12:07 PM, bill-auger wrote:
> great explanation Koichi - thanks - i did not learn anything about the scoping
> or inheritance by reading `info bash trap` or by searching the web

This is from the FUNCTIONS section of the man page. The info document
contains the same language.

"All other aspects of the shell execution environment are identical  be-
 tween  a  function  and its caller with these exceptions: the DEBUG and
 RETURN traps (see the description  of  the  trap  builtin  under  SHELL
 BUILTIN  COMMANDS below) are not inherited unless the function has been
 given the trace attribute (see the description of the  declare  builtin
 below)  or  the -o functrace shell option has been enabled with the set
 builtin (in which case all  functions  inherit  the  DEBUG  and  RETURN
 traps),  and the ERR trap is not inherited unless the -o errtrace shell
 option has been enabled."

The `.' builtin behaves the same way.

 - i mainly
> just wanted to understand the behavior, verify that the original author of this
> code also misunderstood the behavior, or to report a bug if it was behaving
> unexpectedly

These `signals' came in with bash debugger support, and these semantics are
what the debugger needs.

Chet
--
``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/