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IDProjectCategoryView StatusDate SubmittedLast Update
00007061003.1(2013)/Issue7+TC1Shell and Utilitiespublic2013-05-31 20:352019-06-10 08:55
Reporterjilles Assigned To 
PrioritynormalSeverityObjectionTypeEnhancement Request
Status ClosedResolutionAccepted 
NameJilles Tjoelker
OrganizationFreeBSD
User Reference
SectionXCU 2.12
Page Number2353
Line Number74972
Interp StatusApproved
Final Accepted TextSee 0000706:0001653.
Summary0000706: require subshell environment to have its own copy of ulimit
DescriptionUsers/scripts may expect that a ulimit command in a subshell environment does not affect any parent shell environment, like a cd or umask command. In fact, this is the case even in ksh93 which explicitly forks when a non-fork subshell environment tries to change ulimit. If the subshell environment is implemented via fork() or if the parent environment cannot execute any more commands, changes to ulimit do not affect the parent either.

Some historical non-compliant implementations execute command substitutions invoking a single built-in utility in the current shell environment. Apart from the fact that this is non-compliant for other reasons, a lone ulimit command with a new value in a command substitution is also unlikely to occur in practice because there is normally no code to run with the new limit and such a command generates no output.
Desired ActionAdd a new entry to the list "A shell execution environment consists of the following:", under [XSI] shading:

* File size limit as set by ulimit.
Tagstc2-2008

Activities

Don Cragun

2013-06-13 16:09

viewer   bugnote:0001653

Interpretation response
------------------------
The standard states the requirements for subshell execution environments, and conforming implementations must conform to this. However, concerns have been raised about this which are being referred to the sponsor.

Rationale:
-------------
The current standard does not match historic (and desired) practice.

Notes to the Editor (not part of this interpretation):
-------------------------------------------------------
Make the changes suggested in the Desired Action.

ajosey

2013-09-06 04:54

manager   bugnote:0001808

Interpretation Proposed 6 Sep 2013

ajosey

2013-10-14 13:10

manager   bugnote:0001901

Interpretation approved 14 October 2013

Issue History

Date Modified Username Field Change
2013-05-31 20:35 jilles New Issue
2013-05-31 20:35 jilles Name => Jilles Tjoelker
2013-05-31 20:35 jilles Organization => FreeBSD
2013-05-31 20:35 jilles Section => XCU 2.12
2013-05-31 20:35 jilles Page Number => 2353
2013-05-31 20:35 jilles Line Number => 74972
2013-06-13 16:09 Don Cragun Interp Status => ---
2013-06-13 16:09 Don Cragun Final Accepted Text => See 0000706:0001653.
2013-06-13 16:09 Don Cragun Note Added: 0001653
2013-06-13 16:09 Don Cragun Status New => Interpretation Required
2013-06-13 16:09 Don Cragun Resolution Open => Accepted
2013-06-13 16:10 Don Cragun Tag Attached: tc2-2008
2013-06-13 16:11 Don Cragun Interp Status --- => Pending
2013-09-06 04:54 ajosey Interp Status Pending => Proposed
2013-09-06 04:54 ajosey Note Added: 0001808
2013-10-14 13:10 ajosey Interp Status Proposed => Approved
2013-10-14 13:10 ajosey Note Added: 0001901
2019-06-10 08:55 agadmin Status Interpretation Required => Closed