$ cat population.csv
国,首都,人口(2006),id
"日本国","東京","127767944",1
アメリカ合衆国,ワシントン,300007997,2

$ awk -F, '{ print $4 "," $1 "," $2 "," $3 }' population.csv
id,国,首都,人口(2006)
1,"日本国","東京","127767944"
2,アメリカ合衆国,ワシントン,300007997