The three-way merge utility, sm_merge, helps incorporate configuration changes (made in the .conf, .import .asl, .xml, .pl, .sh, and .cmd files) from an old installation into a new installation of a product. The utility performs a three-way merge on each of the files that you have modified.
The utility uses <file_name>.base, <file_name>.local, and <file_name>, and finds the largest sequence of lines that is common to all three files (this sequence need not necessarily be continuous lines). This largest sequence of lines is called the Longest Common Subsequence (LCS). Then, for each of the three files, it finds groups of lines in between two consecutive lines in the LCS. These groups are referred to as “content blocks.”