Setting bash flags in subshells - does it affect parent shell?

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up vote
0
down vote

favorite












I have this in a bash script:



(
 set -o pipefail
 echo "foobar" | bash
 set +o pipefail
)


do I need to reset pipefail setting, or can I just omit that line? In other words, does the pipefail setting in the subshell affect the parent?



So that means I assume that this:



(
 set -o pipefail
 echo "foobar" | bash
)


is really no different than the above?




bash shell-script subshell pipefail




share|improve this question



















  • they probably aren't called bash flags / settings...if you can correct me on the terminology that would be good
    – Alexander Mills
    May 7 at 21:52














up vote
0
down vote

favorite












I have this in a bash script:



(
 set -o pipefail
 echo "foobar" | bash
 set +o pipefail
)


do I need to reset pipefail setting, or can I just omit that line? In other words, does the pipefail setting in the subshell affect the parent?



So that means I assume that this:



(
 set -o pipefail
 echo "foobar" | bash
)


is really no different than the above?




bash shell-script subshell pipefail




share|improve this question



















  • they probably aren't called bash flags / settings...if you can correct me on the terminology that would be good
    – Alexander Mills
    May 7 at 21:52












up vote
0
down vote

favorite









up vote
0
down vote

favorite











I have this in a bash script:



(
 set -o pipefail
 echo "foobar" | bash
 set +o pipefail
)


do I need to reset pipefail setting, or can I just omit that line? In other words, does the pipefail setting in the subshell affect the parent?



So that means I assume that this:



(
 set -o pipefail
 echo "foobar" | bash
)


is really no different than the above?




bash shell-script subshell pipefail




share|improve this question











I have this in a bash script:



(
 set -o pipefail
 echo "foobar" | bash
 set +o pipefail
)


do I need to reset pipefail setting, or can I just omit that line? In other words, does the pipefail setting in the subshell affect the parent?



So that means I assume that this:



(
 set -o pipefail
 echo "foobar" | bash
)


is really no different than the above?





bash shell-script subshell pipefail





share|improve this question










share|improve this question




share|improve this question









asked May 7 at 21:51









Alexander Mills

1,885929




1,885929











  • they probably aren't called bash flags / settings...if you can correct me on the terminology that would be good
    – Alexander Mills
    May 7 at 21:52
















  • they probably aren't called bash flags / settings...if you can correct me on the terminology that would be good
    – Alexander Mills
    May 7 at 21:52















they probably aren't called bash flags / settings...if you can correct me on the terminology that would be good
– Alexander Mills
May 7 at 21:52




they probably aren't called bash flags / settings...if you can correct me on the terminology that would be good
– Alexander Mills
May 7 at 21:52










1 Answer
1






active

oldest

votes

















up vote
2
down vote













To quote the man page:




Changes made to the subshell environment cannot affect the shell's execution environment.




You can test your case easily:



$ set +o pipefail
$ (set -o pipefail)
$ shopt -o | grep pipefail
pipefail off





share|improve this answer





















  • Yeah that's what I though, so no need to unset things at the end of the subshell I guess
    – Alexander Mills
    May 7 at 23:00










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1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes








up vote
2
down vote













To quote the man page:




Changes made to the subshell environment cannot affect the shell's execution environment.




You can test your case easily:



$ set +o pipefail
$ (set -o pipefail)
$ shopt -o | grep pipefail
pipefail off





share|improve this answer





















  • Yeah that's what I though, so no need to unset things at the end of the subshell I guess
    – Alexander Mills
    May 7 at 23:00














up vote
2
down vote













To quote the man page:




Changes made to the subshell environment cannot affect the shell's execution environment.




You can test your case easily:



$ set +o pipefail
$ (set -o pipefail)
$ shopt -o | grep pipefail
pipefail off





share|improve this answer





















  • Yeah that's what I though, so no need to unset things at the end of the subshell I guess
    – Alexander Mills
    May 7 at 23:00












up vote
2
down vote










up vote
2
down vote









To quote the man page:




Changes made to the subshell environment cannot affect the shell's execution environment.




You can test your case easily:



$ set +o pipefail
$ (set -o pipefail)
$ shopt -o | grep pipefail
pipefail off





share|improve this answer













To quote the man page:




Changes made to the subshell environment cannot affect the shell's execution environment.




You can test your case easily:



$ set +o pipefail
$ (set -o pipefail)
$ shopt -o | grep pipefail
pipefail off






share|improve this answer













share|improve this answer



share|improve this answer











answered May 7 at 22:51









Grisha Levit

20116




20116











  • Yeah that's what I though, so no need to unset things at the end of the subshell I guess
    – Alexander Mills
    May 7 at 23:00
















  • Yeah that's what I though, so no need to unset things at the end of the subshell I guess
    – Alexander Mills
    May 7 at 23:00















Yeah that's what I though, so no need to unset things at the end of the subshell I guess
– Alexander Mills
May 7 at 23:00




Yeah that's what I though, so no need to unset things at the end of the subshell I guess
– Alexander Mills
May 7 at 23:00












 

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