Keeping SIDs Consistent Across Files

With some care, it is possible to keep the SIDs consistent across sources composed of multiple files. The trick here is to edit all the files at once. The changes can then be made to whatever files are necessary. Check in all the files (even those not changed). This can be done fairly easily by specifying the SCCS subdirectory as the file name argument to both edit and delta:

$ sccs edit SCCS
.  .  .  
$ sccs delta SCCS

With the delta subcommand, you are prompted for comments only once; the comment is applied to all files being checked in. To determine which files have changed, you can compare the "lines added, deleted, unchanged" fields in each file delta table.