bourne sh, problems with var setting in case/esac

[Andy Crump]

>>>>> On 15 Nov 90 19:05:53 GMT, rdavis at connie.UUCP (Ray Davis) said:

Ray> In <1990Nov15.155604.16714 at usenet.ins.cwru.edu> news at usenet.ins.cwru.edu writes:

>>if i don't pipe esac and not use cat, all is ok, but i want to pipe !

>Sh runs control structures with pipes in a subshell.  Variables set in a
>subshell cannot affect the parent's settings.

Ray> It isn't the control structure that is the problem, it's the
Ray> pipe.  Note that in ksh (and maybe SVR? sh), the pipe causes a
Ray> subshell, but redirecting the output of the case to a file does
Ray> not.  Note also that if you 'cat | case', the case is not in a
Ray> subshell.

I tried this on Intel SVR4 version 2.0 with both ksh and sh and they
behave exactly as everyone describes.  The pipe causes a subshell.
You have been zapped by Mr. SubShell.
--

    -- Andy Crump

    ...!tektronix!reed!littlei!andyc | andyc at littlei.intel.com
    ...!uunet!littlei!andyc          | andyc at littlei.uu.net

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