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Re: for ((i=0; i<3 && i!=1; i++))
From: |
Chet Ramey |
Subject: |
Re: for ((i=0; i<3 && i!=1; i++)) |
Date: |
Mon, 12 Jan 2015 11:40:07 -0500 |
User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 |
On 1/12/15 4:29 AM, l_j_f wrote:
> 1. bash version
> -sh-4.3# bash --version
> GNU bash, version 4.3.0(1)-release (arm-hisiv200-linux-gnu)
> Copyright (C) 2013 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software; you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.
>
> 2. the script
> #!/bin/bash
>
> main() {
> local i
>
> for ((i=0; i<3; i++)); do
> local var
> if [[ "${i}" == "1" ]]; then
> var=1
> fi
>
> echo i=$i var=$var
> done
> }
>
> main "$@"
>
> 3. the result
> -sh-4.3# ./test3.sh
> i=0 var=
> i=1 var=1
> i=2 var=1
> # I think it should be
> i=0 var=
> i=1 var=1
> i=2 var=
Why? You never unset var or set it to the empty string after it's set to 1.
Shell variables don't have `loop scope'.
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU chet@case.edu http://cnswww.cns.cwru.edu/~chet/