Thanks for the clarification.
So 'ignoring whitespace' preceeds 'delimiter-logic' in the case of a single
.
I compared the read and readarray sections and did not have a look at Word
Splitting.
Sorry to bother.
Am Samstag, dem 24.09.2022 um 11:21 -0500 schrieb Dennis Williamson:
>
>
> On Sat, Sep 24, 2022 at 11:02 AM kurt wrote:
> > Configuration Information [Automatically generated, do not change]:
> > Machine: x86_64
> > OS: linux-gnu
> > Compiler: gcc
> > Compilation CFLAGS: -g -O2 -flto=auto -ffat-lto-objects -flto=auto
> > -ffat-lto-objects -fstack-protector-strong -Wformat -Werror=format-security
> > -Wall
> > uname output: Linux kurt-OptiPlex-7020 5.15.0-48-generic #54-Ubuntu SMP Fri
> > Aug 26 13:26:29 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux
> > Machine Type: x86_64-pc-linux-gnu
> >
> > Bash Version: 5.1
> > Patch Level: 16
> > Release Status: release
> >
> > Description:
> > read into an array is inconsistent depending on the value of IFS
> > (tested with ! and ).
> > as compared to readarray, which does the expected splitting count
> > on both values.
> >
> > Code to test the problem:
> >
> > declare -a aa adelim=("!" $'\t')
> > declare s delim
> > declare -i i j
> > for((j=0;j<${#adelim[@]};j++)) do
> > delim="${adelim[$j]}"
> > printf -- 'delim is >%s<\n' "${delim}"
> > s="."
> > for((i=0;i<12;i++)) do
> > if [[ $i -gt 4 && $i -lt 9 ]]; then
> > s+="${delim}"
> > else
> > s+="${delim}$i"
> > fi
> > done
> > printf -- ' >%s<\n' "$s"
> > readarray -d "${delim}" aa <<< "$s"
> > printf -- ' len readarray: %d\n' "${#aa[@]}"
> > IFS="${delim}" read -a aa <<< "$s"
> > printf -- ' len read : %d\n' "${#aa[@]}"
> > done
> >
> > Output is:
> >
> > delim is >!<
> > >.!0!1!2!3!4!9!10!11<
> > len readarray: 13
> > len read : 13
> > delim is > <
> > >. 0 1 2 3 4
> > 9 10 11<
> > len readarray: 13
> > len read : 9
> >
> > Expected for read would also be 13 when IFS is set to .
> >
> >
>
> From man bash:
>
> The shell treats each character of IFS as a delimiter, and splits the
> results of the other expansions into words on these characters. If
> IFS is unset, or its value is exactly , the
> default, then any sequence of IFS characters serves to delimit words.
> If IFS has a value other than the default, then sequences of the
> whitespace characters space and tab are ignored at the beginning and end
> of the word, as long as the whitespace character is in the value of
> IFS (an IFS whitespace character). Any character in IFS that is not
> IFS whitespace, along with any adjacent IFS whitespace characters,
> delimits a field. A sequence of IFS whitespace characters is also
> treated as a delimiter. If the value of IFS is null, no word
> splitting occurs.
>
> Note in particular the next-to-last sentence that begins with "A sequence".
> IFS is used by read but not readarray which has its own delimiter argument.
> See the manual sections for the two commands.
>
