[shell] Trim leading and trailing spaces from a string in awk

I'm trying to remove leading and trailing space in 2nd column of the below input.txt:

Name, Order  
Trim, working
cat,cat1

I have used the below awk to remove leading and trailing space in 2nd column but it is not working. What am I missing?

awk -F, '{$2=$2};1' input.txt

This gives the output as:

Name, Order  
Trim, working
cat,cat1

Leading and trailing spaces are not removed.

If it is safe to assume only one set of spaces in column two (which is the original example):

awk '{print $1$2}' /tmp/input.txt

Adding another field, e.g. awk '{print $1$2$3}' /tmp/input.txt will catch two sets of spaces (up to three words in column two), and won't break if there are fewer.

If you have an indeterminate (large) number of space delimited words, I'd use one of the previous suggestions, otherwise this solution is the easiest you'll find using awk.

The following seems to work:

awk -F',[[:blank:]]*' '{$2=$2}1' OFS="," input.txt

Warning by @Geoff: see my note below, only one of the suggestions in this answer works (though on both columns).

I would use sed:

sed 's/, /,/' input.txt

This will remove on leading space after the , . Output:

Name,Order
Trim,working
cat,cat1

More general might be the following, it will remove possibly multiple spaces and/or tabs after the ,:

sed 's/,[ \t]\?/,/g' input.txt

It will also work with more than two columns because of the global modifier /g

@Floris asked in discussion for a solution that removes trailing and and ending whitespaces in each colum (even the first and last) while not removing white spaces in the middle of a column:

sed 's/[ \t]\?,[ \t]\?/,/g; s/^[ \t]\+//g; s/[ \t]\+$//g' input.txt

*EDIT by @Geoff, I've appended the input file name to this one, and now it only removes all leading & trailing spaces (though from both columns). The other suggestions within this answer don't work. But try: " Multiple spaces , and 2 spaces before here " *

IMO sed is the optimal tool for this job. However, here comes a solution with awk because you've asked for that:

awk -F', ' '{printf "%s,%s\n", $1, $2}' input.txt

Another simple solution that comes in mind to remove all whitespaces is tr -d:

cat input.txt | tr -d ' '

I just came across this. The correct answer is:

awk 'BEGIN{FS=OFS=","} {gsub(/^[[:space:]]+|[[:space:]]+$/,"",$2)} 1'

Simplest solution is probably to use tr

$ cat -A input
^I    Name, ^IOrder  $
  Trim, working  $
cat,cat1^I  

$ tr -d '[:blank:]' < input | cat -A
Name,Order$
Trim,working$
cat,cat1

remove leading and trailing white space in 2nd column

awk 'BEGIN{FS=OFS=","}{gsub(/^[ \t]+/,"",$2);gsub(/[ \t]+$/,"",$2)}1' input.txt

another way by one gsub:

awk 'BEGIN{FS=OFS=","} {gsub(/^[ \t]+|[ \t]+$/, "", $2)}1' infile

just use a regex as a separator:

', *' - for leading spaces

' *,' - for trailing spaces

for both leading and trailing:

awk -F' *,? *' '{print $1","$2}' input.txt