The type of change suffered in converting a given range of a given file to some other is indicated in one of these ways:
The original contents of the range follows immediately after a c indication. When the contents of two files are identical, the contents of the lower-numbered file is suppressed.
Under the -e option, diff3 publishes a script for the editor ed that will incorporate into file1 all changes between file2 and file3, i.e. the changes that normally would be flagged ==== and ====3. Option -x (-3) produces a script to incorporate only changes flagged ==== (====3). The following command will apply the resulting script to `file1'.
(cat script; echo '1,$p') | ed - file1
The -E and -X are similar to -e and -x, respectively, but treat overlapping changes (i.e., changes that would be flagged with ==== in the normal listing) differently. The overlapping lines from both files will be inserted by the edit script, bracketed by "<<<<<<" and ">>>>>>" lines.
For example, suppose lines 7-8 are changed in both file1 and file2. Applying the edit script generated by the command
lines 1-6 of file1 <<<<<<< file1 lines 7-8 of file1 ======= lines 7-8 of file3 >>>>>>> file3 rest of file1
The -E option is used by RCS merge(1) to insure that overlapping changes in the merged files are preserved and brought to someone's attention.