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
BF  Burkina Faso
BN  Brunei Darussalam

And I 'd like to invert the order, printing first everything except $1 and then $1:

United Arab Emirates AE

How can I do the "everything except field 1" trick?

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

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 3

Use the cut command with -f 2- (POSIX) or --complement (not POSIX):

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

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 5

awk '{sub($1 FS,"")}7' YourFile

Remove the first field and separator, and print the result (7 is a non zero value so printing $0).

Answer 6

awk '{ saved = $1; $1 = ""; print substr($0, 2), saved }'

Setting the first field to "" leaves a single copy of OFS at the start of $0. Assuming that OFS is only a single character (by default, it's a single space), we can remove it with substr($0, 2). Then we append the saved copy of $1.

Answer 7

If you're open to a Perl solution...

perl -lane 'print join " ",@F[1..$#F,0]' file

is a simple solution with an input/output separator of one space, which produces:

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

This next one is slightly more complex

perl -F`  ` -lane 'print join "  ",@F[1..$#F,0]' file

and assumes that the input/output separator is two spaces:

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

These command-line options are used:

• -n loop around every line of the input file, do not automatically print every line

• -l removes newlines before processing, and adds them back in afterwards

• -a autosplit mode – split input lines into the @F array. Defaults to splitting on whitespace

• -F autosplit modifier, in this example splits on ' ' (two spaces)

• -e execute the following perl code

@F is the array of words in each line, indexed starting with 0
$#F is the number of words in @F
@F[1..$#F] is an array slice of element 1 through the last element
@F[1..$#F,0] is an array slice of element 1 through the last element plus element 0

Answer 8

Let's move all the records to the next one and set the last one as the first:

$ awk '{a=$1; for (i=2; i<=NF; i++) $(i-1)=$i; $NF=a}1' file
United Arab Emirates AE
Antigua & Barbuda AG
Netherlands Antilles AN
American Samoa AS
Bosnia and Herzegovina BA
Burkina Faso BF
Brunei Darussalam BN

Explanation

• a=$1 save the first value into a temporary variable.
• for (i=2; i<=NF; i++) $(i-1)=$i save the Nth field value into the (N-1)th field.
• $NF=a save the first value ($1) into the last field.
• {}1 true condition to make awk perform the default action: {print $0}.

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This way, if you happen to have another field separator, the result is also good:

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

$ awk 'BEGIN{OFS=FS="-"}{a=$1; for (i=2; i<=NF; i++) $(i-1)=$i; $NF=a}1' c
United-Arab-Emirates-AE
Antigua-&-Barbuda-AG
Netherlands-Antilles-AN
American-Samoa-AS
Bosnia-and-Herzegovina-BA
Burkina-Faso-BF
Brunei-Darussalam-BN

Answer 9

The field separator in gawk (at least) can be a string as well as a character (it can also be a regex). If your data is consistent, then this will work:

awk -F "  " '{print $2,$1}' inputfile

That's two spaces between the double quotes.