Bug 12578
| Summary: | `cd somewhere` changes current working directory in /bin/sh scripts | ||
|---|---|---|---|
| Product: | Base System | Reporter: | pfeifer <pfeifer> |
| Component: | bin | Assignee: | Sheldon Hearn <sheldonh> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | 3.2-RELEASE | ||
| Hardware: | Any | ||
| OS: | Any | ||
Sheldon Hearn wrote: > cd /tmp > echo .`cd /`. > pwd > > Any takers? The patch appended seems to fix this, I'd like someone familiar with sh to review it though, since this may be symptomatic of a general problem with command substitution. > PS: And no, this is not an invitation to chat about the default shell > for the base system. :-) You're hinting it should be /bin/sh for root, right? Regards, Niall *** eval.c~ Mon May 10 16:10:16 1999 --- eval.c Mon Jul 12 18:27:44 1999 *************** *** 710,715 **** --- 710,716 ---- && ((flags & EV_EXIT) == 0 || Tflag)) || ((flags & EV_BACKCMD) != 0 && (cmdentry.cmdtype != CMDBUILTIN + || cmdentry.u.index == CDCMD || cmdentry.u.index == DOTCMD || cmdentry.u.index == EVALCMD))) { jp = makejob(cmd, 1); State Changed From-To: open->feedback Could you try Niall Smart's patch to src/bin/sh/eval.c and provide feedback? Responsible Changed From-To: freebsd-bugs->sheldonh I'll take this one. State Changed From-To: feedback->closed Committed, thanks! |
`man sh` says Command Substitution Command substitution allows the output of a command to be substituted in place of the command name itself. Command substitution occurs when the command is enclosed as follows: $(command) or (``backquoted'' version): `command` The shell expands the command substitution by executing command in a sub- shell environment and replacing the command substitution with the stan- dard output of the command, yet a `cd /some/where` actually does change the current working directory of a shell script it occurs in, i.e., apparently it is not invoked in a sub-shell. Debian GNU/Linux 2.1 (with bash), Solaris 2.6, AIX 4.1 and DEC OSF1 4.0 behave as expected, see "How to repeat the problem". Fix: Replace /bin/sh by bash. How-To-Repeat: Run the following script: #!/bin/sh cd /tmp echo .`cd /`. pwd The expected output (as obtained on Solaris 2.6, Debian GNU/Linux 2.1, AIX 4.1 and DEC OSF1 4.0) is as follows .. /tmp while FreeBSD 3.2 incorrectly prints .. /