Index: join/join.1 =================================================================== --- join/join.1 +++ join/join.1 @@ -164,6 +164,125 @@ the standard input is used. .Sh EXIT STATUS .Ex -std +.Sh EXAMPLES +Assuming a file named nobel_laureates.txt with information about the first Nobel +Peace Prize laureates: +.Bd -literal -offset indent +1901,Jean Henri Dunant,M +1901,Frederic Passy,M +1902,Elie Ducommun,M +1902,Charles Albert Gobat,M +1903,Sir William Randal Cremer,M +1904,Institute Of International Law, +1905,Baroness Bertha Sophie Felicita Von Suttner,F +1906,Theodore Roosevelt,M +1907,Ernesto Teodoro Moneta,M +1907,Louis Renault,M +1908,Klas Pontus Arnoldson,M +1908,Fredrik Bajer,M +1909,Auguste Marie Francois Beernaert,M +1909,Paul Henri Benjamin Balluet d'Estournelles de Constant,M +1910,Permanent International Peace Bureau, +.Ed +.Pp +and a second file nobel_nationalities.txt with their nationalities: +.Bd -literal -offset indent +Jean Henri Dunant,Switzerland +Frederic Passy,France +Elie Ducommun,Switzerland +Charles Albert Gobat,Switzerland +Sir William Randal Cremer,UK +Institute Of International Law,Belgium +Baroness Bertha Sophie Felicita Von Suttner +Theodore Roosevelt,USA +Ernesto Teodoro Moneta,Italy +Louis Renault,France +Klas Pontus Arnoldson,Sweden +Fredrik Bajer,Denmark +Auguste Marie Francois Beernaert,Belgium +Paul Henri Benjamin Balluet d'Estournelles de Constant,France +.Ed +.Pp +Join the two files using the second column from first file and the default first +column from second file specifying a custom field delimiter: +.Bd -literal -offset indent +$ join -t, -1 2 nobel_laureates.txt nobel_nationalities.txt +Jean Henri Dunant,1901,M,Switzerland +Frederic Passy,1901,M,France +Elie Ducommun,1902,M,Switzerland +Charles Albert Gobat,1902,M,Switzerland +Sir William Randal Cremer,1903,M,UK +Institute Of International Law,1904,,Belgium +Baroness Bertha Sophie Felicita Von Suttner,1905,F +Theodore Roosevelt,1906,M,USA +Ernesto Teodoro Moneta,1907,M,Italy +Louis Renault,1907,M,France +Klas Pontus Arnoldson,1908,M,Sweden +Fredrik Bajer,1908,M,Denmark +Auguste Marie Francois Beernaert,1909,M,Belgium +Paul Henri Benjamin Balluet d'Estournelles de Constant,1909,M,France +.Ed +.Pp +Show only the year and the nationality of the laureate using "<>" to +replace empty fields: +.Bd -literal -offset indent +$ join -e "<>" -t, -1 2 -o "1.1 2.2" nobel_laureates.txt nobel_nationalities.txt +1901,Switzerland +1901,France +1902,Switzerland +1902,Switzerland +1903,UK +1904,Belgium +1905,<> +1906,USA +1907,Italy +1907,France +1908,Sweden +1908,Denmark +1909,Belgium +1909,France +.Ed +.Pp +Show only lines from first file which don't have a match in second file: +.Bd -literal -offset indent +$ join -v1 -t, -1 2 nobel_laureates.txt nobel_nationalities.txt +Permanent International Peace Bureau,1910, +.Ed +.Pp +Assuming a file named capitals.txt with the following content: +.Bd -literal -offset indent +Belgium,Brussels +Denmark,Copenhagen +France,Paris +Italy,Rome +Sweden,Stockholm +Switzerland, +UK,London +USA,Washington +.Ed +.Pp +Show the name and capital of the country where the laureate was born. +This example uses nobel_nationalities.txt as a bridge but doesn't show any +information from that file. +Also see the note about +.Xr sort 1 +above to understand why we need to sort the intermediate result. +.Bd -literal -offset indent +$ join -t, -1 2 -o 1.2 2.2 nobel_laureates.txt nobel_nationalities.txt | sort -k2 -t, | join -t, -1 2 -o 1.1 2.2 - capitals.txt +Auguste Marie Francois Beernaert,Brussels +Institute Of International Law,Brussels +Fredrik Bajer,Copenhagen +Frederic Passy,Paris +Louis Renault,Paris +Paul Henri Benjamin Balluet d'Estournelles de Constant,Paris +Ernesto Teodoro Moneta,Rome +Klas Pontus Arnoldson,Stockholm +Charles Albert Gobat, +Elie Ducommun, +Jean Henri Dunant, +Sir William Randal Cremer,London +Theodore Roosevelt,Washington +.Ed .Sh COMPATIBILITY For compatibility with historic versions of .Nm ,