https://invisible-island.net/ded/sccs_tools/
getdelta - SCCS check-out utility
getdelta [options] [file-specifications]
Getdelta is a simple interface to sccs (source code control system), which is used to extract files from sccs archives.
Getdelta checks out (extracts) files from an sccs archive which have been checked in using putdelta (orsccsput, which invokes it). Putdelta checks in files, retaining their modification date as the check-in date. Getdelta extracts a given version of one or more files, and sets the modification date to match the check-in date.
Getdelta is a package (which invokes sccs's get) which does special things with the file modification date. Most of its options are passed to get, and then interpreted to determine the correct modification date: -ccutoff specifies the sccs cutoff date, in the format YY[MM[DD[HH[MM[SS]]]]] Punctuation in the date is permitted. For example, -c 77/2/2 9:22:25 -c 770202092225 represent the same date. -f forces getdelta to remove the current version of the file before extracting the specified version. Otherwise, getdelta will refuse to overwrite a file which already exists. -k directs get to extract the specified file without substituting sccs identification keywords. You should use this option if you intend to make updates to the file. -n suppresses the get-operation. Instead, getdelta echoes a message showing the name, version and date of files which would be extracted. -rSID specifies the sccs identification string (SID) of the version of an sccs file to be retrieved. -s suppresses most messages written by the get utility (i.e., those written to standard output).
To extract files using getdelta, you must provide one or more names. They must be the names either of the working files, or of the archive "s." files.
Getdelta invokes the sccs utility get, which must be in your path. Environment variables used by getdelta include: SCCS_DIR specifies the directory in which getdelta will find the "s." files. If not specified, getdelta assumes "SCCS". TZ is the timezone, which getdelta manipulates to obtain the file's modification date. It assumes that the timezone of the check-in date in the "s." file is EST5EDT.
Getdelta consists of a single binary file written in C. It runs in a POSIX environment.
None.
putdelta, sccsget, sccsput, get (1)
Thomas Dickey (Software Productivity Consortium). GETDELTA(1)