Info Catalog diffutils: Detailed diff3 Normal diffutils: Comparing Three Files

diffutils: diff3 Hunks

 
 7.4 'diff3' Hunks
 =================
 
 Groups of lines that differ in two or three of the input files are
 called "diff3 hunks", by analogy with 'diff' hunks (⇒Hunks).  If
 all three input files differ in a 'diff3' hunk, the hunk is called a
 "three-way hunk"; if just two input files differ, it is a "two-way
 hunk".
 
    As with 'diff', several solutions are possible.  When comparing the
 files 'A', 'B', and 'C', 'diff3' normally finds 'diff3' hunks by merging
 the two-way hunks output by the two commands 'diff A B' and 'diff A C'.
 This does not necessarily minimize the size of the output, but
 exceptions should be rare.
 
    For example, suppose 'F' contains the three lines 'a', 'b', 'f', 'G'
 contains the lines 'g', 'b', 'g', and 'H' contains the lines 'a', 'b',
 'h'.  'diff3 F G H' might output the following:
 
      ====2
      1:1c
      3:1c
        a
      2:1c
        g
      ====
      1:3c
        f
      2:3c
        g
      3:3c
        h
 
 because it found a two-way hunk containing 'a' in the first and third
 files and 'g' in the second file, then the single line 'b' common to all
 three files, then a three-way hunk containing the last line of each
 file.
 

Info Catalog diffutils: Detailed diff3 Normal diffutils: Comparing Three Files