[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: bash: bug report Here document and Command substitution
From: |
Yves Crespin |
Subject: |
RE: bash: bug report Here document and Command substitution |
Date: |
Mon, 22 Jan 2001 21:52:31 +0100 |
This command follow POSIX rules and it's work fine with the Korn shell.
-----Message d'origine-----
De: Chet Ramey [SMTP:chet@nike.INS.CWRU.Edu]
Date: samedi 20 janvier 2001 18:31
À: ycrespin@compuserve.com
Cc: bug-bash@gnu.org; chet@po.cwru.edu
Objet: Re: bash: bug report Here document and Command substitution
> The following syntax do not work (parse error).
>
> echo $(cat <<-EOF
> this is a )
> EOF
> )
It's lazy evaluation. Bash doesn't parse the contents of a command
substitution until it's time for the command to be executed. Since
the closing right paren is seen first, before the here document
parse is attempted, a syntax error will occur later.
Parsing commands inside $(...) at the same time the command containing
the $(...) is being parsed is very hard to do with a yacc-based parser.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
( ``Discere est Dolere'' -- chet)
Chet Ramey, CWRU chet@po.CWRU.Edu http://cnswww.cns.cwru.edu/~chet/