Bug 49038
| Summary: | /bin/sh does not undefine a function when unset is issued | ||
|---|---|---|---|
| Product: | Base System | Reporter: | Jukka A. Ukkonen <jau> |
| Component: | bin | Assignee: | freebsd-bugs (Nobody) <bugs> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | Unspecified | ||
| Hardware: | Any | ||
| OS: | Any | ||
Hello. > The bourne shell does not undefine a previously declared shell > function when unset command is given though the manual pages > so imply. I think it is pretty clear that a plain "unset name" does not undefine functions. From the sh(1) manual page: """ unset [-fv] name ... The specified variables or functions are unset and unexported. If the -v option is specified or no options are given, the name arguments are treated as variable names. If the -f option is specified, the name arguments are treated as function names. """ > This is a serious portability problem for imported shell scripts. If these shell scripts rely on "unset name" to remove a function named "name", they should be regarded as unportable. From POSIX.1-2001: """ If neither -f nor -v is specified, name refers to a variable; if a variable by that name does not exist, it is unspecified whether a function by that name, if any, shall be unset. """ ciao, -robert State Changed From-To: open->feedback Waiting on response from originator. State Changed From-To: feedback->closed The bourne shell in both 4.7-RELEASE and -CURRENT distinguishes between variables and functions in its `unset' command. To unset functions, the `-f' flag must be explicitly given. The problem lay in the documentation of earlier FreeBSD versions. Originator considers PR resolved. |
The bourne shell does not undefine a previously declared shell function when unset command is given though the manual pages so imply. This is a serious portability problem for imported shell scripts. Just figure how will a script behave, if there is a function called exit which invokes another function which in turn tries first "unset exit", does its own work and now tries to invoke the real exit... Exit() { unset exit Logger -stderr "$*" exit 0 } exit() { ... Exit "EXIT:" "$*" } Fix: This is probably simple oversight in forgetting to clean the unset name in the function symbol table though the variable name gets gets cleared out of the variable symbol table. How-To-Repeat: sticky() { echo "STICKY STILL HERE" echo "$*" } unset sticky sticky peekaboo STICKY STILL HERE peekaboo The last two lines are the output from the echo.