1ed is an 8-bit-clean, POSIX-compliant line editor. It should work with
2any regular expression package that conforms to the POSIX interface
3standard, such as GNU regex(3).
4
5If reliable signals are supported (e.g., POSIX sigaction(2)), it should
6compile with little trouble. Otherwise, the macros SPL1() and SPL0()
7should be redefined to disable interrupts.
8
9The following compiler directives are recognized:
10DES - to add encryption support (requires crypt(3))
11NO_REALLOC_NULL - if realloc(3) does not accept a NULL pointer
12BACKWARDS - for backwards compatibility
13NEED_INSQUE - if insque(3) is missing
14
15The file `POSIX' describes extensions to and deviations from the POSIX
16standard.
17
18The ./test directory contains regression tests for ed. The README
19file in that directory explains how to run these.
20
21For a description of the ed algorithm, see Kernighan and Plauger's book
22"Software Tools in Pascal," Addison-Wesley, 1981.