xref: /freebsd/bin/ed/README (revision 5aa839c9e2c373275091b8bf529c1311d0b84d76)
1 $FreeBSD$
2 
3 ed is an 8-bit-clean, POSIX-compliant line editor.  It should work with
4 any regular expression package that conforms to the POSIX interface
5 standard, such as GNU regex(3).
6 
7 If reliable signals are supported (e.g., POSIX sigaction(2)), it should
8 compile with little trouble.  Otherwise, the macros SPL1() and SPL0()
9 should be redefined to disable interrupts.
10 
11 The following compiler directives are recognized:
12 NO_REALLOC_NULL	- if realloc(3) does not accept a NULL pointer
13 BACKWARDS	- for backwards compatibility
14 NEED_INSQUE	- if insque(3) is missing
15 
16 The file `POSIX' describes extensions to and deviations from the POSIX
17 standard.
18 
19 The ./test directory contains regression tests for ed. The README
20 file in that directory explains how to run these.
21 
22 For a description of the ed algorithm, see Kernighan and Plauger's book
23 "Software Tools in Pascal," Addison-Wesley, 1981.
24