Re: GNU bash, 3.00.15(1)-release, referenced cmd in cwd executes alternate cmd

[Matthew Woehlke]

Bojan Land wrote:
> Under what circumstances does the gnu-bash path hash differ from that of
> the $PATH variable?  Why is it even possible for this difference to
> occur?

Because bash uses a hash to speed look-up of frequently used commands. 
The only way to (almost) always get the right command every time is to 
do a $PATH lookup every time, which would of course defeat the purpose 
of having a hash. At least, that's my guess.

Anyway you would still have a race condition e.g. if PATH is 
'/usr/local/bin:/usr/bin:/bin' and a program appears in e.g. 
/usr/local/bin right after bash checks there (and, say, ultimately finds 
the program in /bin). By the time bash fork()s and exec()s, it is using 
the "wrong" version. So there isn't really any way to "fix" the problem; 
the hash just puts the onus on the user to force a refresh when things 
change (and meanwhile reduces I/O).

--
Matthew
Caution: keep out of reach of adults.