xref: /original-bsd/contrib/ed/README (revision b806d041)
1#	@(#)README	5.2 (Berkeley) 03/01/93
2
3For compiling:
4	There are several flag options for compiling 'ed' into executable.
5
6This table briefly describes the flags used in compilation:
7
8	BSD | POSIX
9		specifies over-riding behaviour in historical terms:
10		BSD=> BSD behaviour when confilicting with P1003.2,
11		POSIX=> as P1003.2 specified when conflicting with BSD.
12
13	STDIO | DBI | MEMORY
14		specifies which method is to be used for the buffer.
15                Be sure to understand that there are trade-offs with
16                any of the methods:
17		STDIO=> standard I/O temp file,
18		DBI=> BSD recno database file (db(3)),
19		MEMORY=> ye olde silicon.
20
21	One of each compile flag option _must_ be chosen to get a sensible
22	compile.
23
24One define not listed above, yet used as a flag, is RE_STARTEND. This
25is used to automagically check if you are using the real BSD RE interfaces.
26See regex(3) (4.4BSD) for a description of RE_STARTEND; an extension to
27P1003.2 B.5. If you happen to be using another POSIX regex(3) this
28automatically taken care of; the old RE interfaces are unsupported.
29
30This implementation of `ed' is a superset of the POSIX 1003.2 description
31for `ed' to remain compatible with earlier (BSD) versions of `ed'.
32Hence, any BSD 'ed'isms that do not conflict with P1003.2 are available
33to the user even under the POSIX flag compilation. Likewise, any POSIX
34'ed'isms that do not conflict with historical BSD behaviour are available
35to the user.
36
37Refer to the man page ed(1) for information about using `ed'.
38
39-Rodney
40