Shell Programming and Scripting

243
242
243
242
242

243          car       360    396k
242          bike       240    217k

243 360
242 240
243 360
242 240
242 240

 while read y; do
                while read z; do

                done<file1
        done<file2

while read y; do
                while read z; do
                        a=$(echo $y | awk '{print $1}')
                        if [ "$a" = "$z" ]; then
                                echo $y
                        else
                                echo nomatch
                        fi
                done<file1
        done<file2

 awk 'FNR==NR{X[$1]=$3;next} ($1 in X){print $1 OFS X[$1]}' file2 file1

243 360
242 240
243 360
242 240
242 240

awk 'NR == FNR {a[$1] = $3; next} {print $1, (a[$1] == "" ? "nomatch" : a[$1])}' file2 file1