Shell Programming and Scripting

awk  'NR==FNR { a[$1 FS $2]=$0; next } $1 FS $2 in a { printf a[$1 FS $2]; sub($1 FS $2,""); print }' file1 file2 > file3

nawk '{
if (NR==FNR)
	_[$1$2]=$0
else
{
	if (_[$1$2]!=""){
		printf("%s",_[$1$2])
		for(i=3;i<=NF;i++)
			printf(" %s",$i)
		printf "\n"
	}
}
}' file1 file2

NR==FNR {         # while in the first file, 
a[$1 FS $2]=$0    #+load array a indexed by first field, space ( default FS ), second field;  
next              #+then jump to the next record, without testing the following actions for the current record.  }
$1 FS $2 in a {   # Here starts the processing of file2. If field 1, space, and field 2 are found as indexes in array a, 
printf a[$1FS$2]  #+print the whole record ($0) of file 1 saved above in the array a ; 
sub($1 FS $2,"")  # substitute field 1, field 2 ( including the space in between ) with null string ;
print             # print the whole current record ( what's left ) of the second file.  }

#!/usr/bin/env bash

# @(#) s2       Demonstrate join on 2 adjacent fields.

echo
set +o nounset
LC_ALL=C ; LANG=C ; export LC_ALL LANG
echo "Environment: LC_ALL = $LC_ALL, LANG = $LANG"
echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version "=o" $(_eat $0 $1) sed join
set -o nounset
echo

FILE1=data1
FILE2=data2

echo " Data file $FILE1:"
cat $FILE1

echo
echo " Data file $FILE2:"
cat $FILE2

# Pre-process input / sort, join / post-process output.
echo
echo " Results:"
sed 's/ /_/' $FILE1 | sort -k1,1 >t1
sed 's/ /_/' $FILE2 | sort -k1,1 >t2

join -j 1 t1 t2 | sed 's/_/ /'

echo
echo " Expected output:"
cat expected-output.txt

exit 0

$ ./s2

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: SunOS, 5.10, i86pc
GNU bash 3.00.16
sed - ( /usr/xpg4/bin/sed Aug 9 2005 )
join - ( /usr/bin/join Jan 22 2005 )

 Data file data1:
123 234 678 974 943
345 55 567 21 357
456 732 583 61 75

 Data file data2:
123 234 582 699 23 11 935
22 467 215 376 87 54
456 732 32 14

 Results:
123 234 678 974 943 582 699 23 11 935
456 732 583 61 75 32 14

 Expected output:
123 234 678 974 943 582 699 23 11 935
456 732 583 61 75 32 14