Printing everything except the first field with awk

Question

I have a file that looks like this:

AE  United Arab Emirates
AG  Antigua & Barbuda
AN  Netherlands Antilles
AS  American Samoa
BA  Bosnia and Herzegovina         


        

Answer 1

$1="" leaves a space as Ben Jackson mentioned, so use a for loop:

awk '{for (i=2; i<=NF; i++) print $i}' filename

So if your string was "one two three", the output will be:

two
three

If you want the result in one row, you could do as follows:

awk '{for (i=2; i<NF; i++) printf $i " "; print $NF}' filename

This will give you: "two three"

Answer 2

If you're open to another Perl solution:

perl -ple 's/^(\S+)\s+(.*)/$2 $1/' file

Answer 3

Use the cut command with the --complement option:

$ echo a b c | cut -f 1 -d ' '
a
$ echo a b c | cut -f 1,2 -d ' '
a b
$ echo a b c | cut -f 1 -d ' ' --complement
b c

Answer 4

Assigning $1 works but it will leave a leading space: awk '{first = $1; $1 = ""; print $0, first; }'

You can also find the number of columns in NF and use that in a loop.

Answer 5

Maybe the most concise way:

$ awk '{$(NF+1)=$1;$1=""}sub(FS,"")' infile
United Arab Emirates AE
Antigua & Barbuda AG
Netherlands Antilles AN
American Samoa AS
Bosnia and Herzegovina BA
Burkina Faso BF
Brunei Darussalam BN

Explanation:

$(NF+1)=$1: Generator of a "new" last field.

$1="": Set the original first field to null

sub(FS,""): After the first two actions {$(NF+1)=$1;$1=""} get rid of the first field separator by using sub. The final print is implicit.

Answer 6

Option 1

There is a solution that works with some versions of awk:

awk '{ $(NF+1)=$1;$1="";$0=$0;} NF=NF ' infile.txt

Explanation:

       $(NF+1)=$1                          # add a new field equal to field 1.
                  $1=""                    # erase the contents of field 1.
                        $0=$0;} NF=NF      # force a re-calc of fields.
                                           # and use NF to promote a print.

Result:

United Arab Emirates AE
Antigua & Barbuda AG
Netherlands Antilles AN
American Samoa AS
Bosnia and Herzegovina BA
Burkina Faso BF
Brunei Darussalam BN

However that might fail with older versions of awk.

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Option 2

awk '{ $(NF+1)=$1;$1="";sub(OFS,"");}1' infile.txt

That is:

awk '{                                      # call awk.
       $(NF+1)=$1;                          # Add one trailing field.
                  $1="";                    # Erase first field.
                        sub(OFS,"");        # remove leading OFS.
                                    }1'     # print the line.

Note that what needs to be erased is the OFS, not the FS. The line gets re-calculated when the field $1 is asigned. That changes all runs of FS to one OFS.

---

But even that option still fails with several delimiters, as is clearly shown by changing the OFS:

awk -v OFS=';' '{ $(NF+1)=$1;$1="";sub(OFS,"");}1' infile.txt

That line will output:

United;Arab;Emirates;AE
Antigua;&;Barbuda;AG
Netherlands;Antilles;AN
American;Samoa;AS
Bosnia;and;Herzegovina;BA
Burkina;Faso;BF
Brunei;Darussalam;BN

That reveals that runs of FS are being changed to one OFS.
The only way to avoid that is to avoid the field re-calculation.
One function that can avoid re-calc is sub.
The first field could be captured, then removed from $0 with sub, and then both re-printed.

Option 3

awk '{ a=$1;sub("[^"FS"]+["FS"]+",""); print $0, a;}' infile.txt
       a=$1                                   # capture first field.
       sub( "                                 # replace: 
             [^"FS"]+                         # A run of non-FS
                     ["FS"]+                  # followed by a run of FS.
                            " , ""            # for nothing.
                                  )           # Default to $0 (the whole line.
       print $0, a                   # Print in reverse order, with OFS.


United Arab Emirates AE
Antigua & Barbuda AG
Netherlands Antilles AN
American Samoa AS
Bosnia and Herzegovina BA
Burkina Faso BF
Brunei Darussalam BN

Even if we change the FS, the OFS and/or add more delimiters, it works.
If the input file is changed to:

AE..United....Arab....Emirates
AG..Antigua....&...Barbuda
AN..Netherlands...Antilles
AS..American...Samoa
BA..Bosnia...and...Herzegovina
BF..Burkina...Faso
BN..Brunei...Darussalam

And the command changes to:

awk -vFS='.' -vOFS=';' '{a=$1;sub("[^"FS"]+["FS"]+",""); print $0,a;}' infile.txt

The output will be (still preserving delimiters):

United....Arab....Emirates;AE
Antigua....&...Barbuda;AG
Netherlands...Antilles;AN
American...Samoa;AS
Bosnia...and...Herzegovina;BA
Burkina...Faso;BF
Brunei...Darussalam;BN

The command could be expanded to several fields, but only with modern awks and with --re-interval option active. This command on the original file:

awk -vn=2 '{a=$1;b=$2;sub("([^"FS"]+["FS"]+){"n"}","");print $0,a,b;}' infile.txt

Will output this:

Arab Emirates AE United
& Barbuda AG Antigua
Antilles AN Netherlands
Samoa AS American
and Herzegovina BA Bosnia
Faso BF Burkina
Darussalam BN Brunei