On 23 Mar 2011, at 21:15, Sam Liddicott wrote: > > On 23/03/11 18:52, Chris F.A. Johnson wrote: >> >> On Wed, 23 Mar 2011, Sam Liddicott wrote: >> >>> >>> Configuration Information [Automatically generated, do not change]: >>> Machine: i686 >>> OS: linux-gnu >>> Compiler: gcc >>> Compilation CFLAGS: -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' >>> -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' >>> -DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DP$ uname output: Linux >>> sojo 2.6.35-28-generic-pae #49-Ubuntu SMP Tue Mar 1 14:58:06 UTC 2011 i686 >>> GNU/Linux >>> Machine Type: i686-pc-linux-gnu >>> >>> Bash Version: 4.1 >>> Patch Level: 5 >>> Release Status: release >>> >>> Description: >>> man page says: >>> >>> BASH_SUBSHELL >>> Incremented by one each time a subshell or subshell environment >>> is spawned. The initial value is 0. >>> >>> This suggests that: >>> >>> echo $BASH_SUBSHELL ; ( echo ) ; echo $BASH_SUBSHELL >>> >>> would not give the same answer for BASH_SUBSHELL >> >> No, it suggests that: >> >> echo $BASH_SUBSHELL ; ( echo $BASH_SUBSHELL ) >> >> would not give the same answer for BASH_SUBSHELL > > It should suggest that, because that is how it actually works. > > But the man page is misleading and does not actually suggest this. > >> >> In your example, the second "echo $BASH_SUBSHELL" is at the same >> depth as the first. >> > > Yes. But a new subshell environment has been spawned. Each time that happens > BASH_SUBSHELL should increase. > > Of course I know how it does work, but the man page isn't clear. It doesn't > say that the increase is only visible within the subshell and therefore it is > a measurement of subshell depth. > > Sam >
I must concur. In the bug example at the second expansion of BASH_SUBSHELL occurs after "a subshell or subshell environment is spawned". The documentation does not specify that BASH_SUBSHELL is actually unmodified in the running shell and merely copied to the subshell and incremented there. What's more, the fact that this is not mentioned, grammatically suggests that BASH_SUBSHELL is modified, which is not actually the case.
