On 7/7/16 3:01 PM, Todd Merriman wrote:
> Bash Version: 4.2
> Patch Level: 46
> Release Status: release
>
> Description:
> IFS=' ' # TAB
> program_outputting_tab_delimited_fields |
> while read -r FLD1 FLD2 FLD3 FLD4
> do
> echo field1=$FLD1
> echo field2=$FLD2
> echo field3=$FLD3
> echo field4=$FLD4
> done
>
> Repeat-By:
> If any fields are empty, the data is read into the preceding field.
> In other words, if in the example FLD3 is empty, FLD4 is read into
> FLD3. If FLD2 and FLD3 are empty, FLD4 is read into FLD1.
This is the correct behavior. Sequences of multiple whitespace characters
delimit fields, as long as those whitespace characters are in $IFS. This
is explained in the man page, in the paragraph that begins:
"The shell treats each character of IFS as a delimiter..."
It reads, in part, "A sequence of IFS whitespace characters is also
treated as a delimiter." The paragraph explains what IFS whitespace
characters are.
Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU [email protected] http://cnswww.cns.cwru.edu/~chet/
