Info Catalog coreutils: Sorting files for join coreutils: join invocation coreutils: Paired and unpaired lines

coreutils: Working with fields

 
 8.3.3 Working with fields
 -------------------------
 
 Use ‘-1’,‘-2’ to set the key fields for each of the input files.  Ensure
 the preceding ‘sort’ commands operated on the same fields.
 
 The following example joins two files, using the values from seventh
 field of the first file and the third field of the second file:
 
      $ sort -k 7b,7 file1 > file1.sorted
      $ sort -k 3b,3 file2 > file2.sorted
      $ join -1 7 -2 3 file1.sorted file2.sorted > file3
 
 If the field number is the same for both files, use ‘-j’:
 
      $ sort -k4b,4 file1 > file1.sorted
      $ sort -k4b,4 file2 > file2.sorted
      $ join -j4    file1.sorted file2.sorted > file3
 
 Both ‘sort’ and ‘join’ operate of whitespace-delimited fields.  To
 specify a different delimiter, use ‘-t’ in _both_:
 
      $ sort -t, -k3b,3 file1 > file1.sorted
      $ sort -t, -k3b,3 file2 > file2.sorted
      $ join -t, -j3    file1.sorted file2.sorted > file3
 
 To specify a tab (ASCII 0x09) character instead of whitespace, use (1):
 
      $ sort -t$'\t' -k3b,3 file1 > file1.sorted
      $ sort -t$'\t' -k3b,3 file2 > file2.sorted
      $ join -t$'\t' -j3    file1.sorted file2.sorted > file3
 
 If ‘join -t ''’ is specified then the whole line is considered which
 matches the default operation of sort:
 
      $ sort file1 > file1.sorted
      $ sort file2 > file2.sorted
      $ join -t '' file1.sorted file2.sorted > file3
 
    ---------- Footnotes ----------
 
    (1) the ‘$'\t'’ is supported in most modern shells.  For older
 shells, use a literal tab
 

Info Catalog coreutils: Sorting files for join coreutils: join invocation coreutils: Paired and unpaired lines