A csv file with multiple records is delimited by |.
field1|field2|field3|field4|field5 I want to check if field3 is blank or contains "space" characters only. If it is blank or space, the whole line should show up.
asked Jul 8, 2009 at 21:48
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5 Answers
$ echo "1|2||4" | awk -F'|' '$3 ~ /^[ \t]*$/ {print $0}' 1|2||4 $ echo "1|2| |4" | awk -F'|' '$3 ~ /^[ \t]*$/ {print $0}' 1|2| |4 $ echo "1|2| 3|4" | awk -F'|' '$3 ~ /^[ \t]*$/ {print $0}' 
You can also use the cut command to pull out the third field and then test the value:
$ echo "field1|field2|field3|field4|field5" | cut -d '|' -f 3 field3 answered Jul 8, 2009 at 23:11
- More readable than awk for this trivial situation if y' ask me (which nobody did ;))Tom Newton– Tom Newton2009-07-09 07:08:22 +00:00Commented Jul 9, 2009 at 7:08
My random attempt using grep would be:
grep -E '^[^|]*\|[^|]*\| *[^| ]+ *\|' file 
- The trouble with this approach is that it isn't general, so if you want to select on the 14th field it would become hateful.James– James2009-07-08 23:27:15 +00:00Commented Jul 8, 2009 at 23:27
- 1@James: Then try something like: "grep -E '^([^|]*\|){13} *[^| ]+ *\|' file" adjusting the value "13" appropriatelyJMusgrove– JMusgrove2009-07-13 22:38:11 +00:00Commented Jul 13, 2009 at 22:38
I'm not certain about unix, but in linux you would want to use the sed command.
sed 's/||/\n/g' will make it so that if there are any blank fields it will add a new line. not certain how to get it to only check the 3rd field. sed 's/| |/\n/g' should work for only spaces.
- linux is a form of unix. Most things that are in linux are in other unixes.Amandasaurus– Amandasaurus2009-07-16 12:40:34 +00:00Commented Jul 16, 2009 at 12:40
- was this comment necessary? Sed, Awk, Grep and the like are SIMILAR across *NIX and BSD systems, but not always the same.Tedd Johnson– Tedd Johnson2009-07-23 19:53:32 +00:00Commented Jul 23, 2009 at 19:53
Using Perl:
perl -F'\|' -lane 'print if $F[2] !~ /\S/' file
-a turns on autosplit mode, which splits the fields into array @F
-F'\|' sets the field delimiter to |
$F[2] is the 3rd field
!~ /\S/ tests for non-space characters (or empty)
