ed: save space in editor buffer

[mknos]

• The substitution s/\z/NEW/ produced the unwanted outcome of $lines[$x] containing two lines of text
• Address this by not including trailing newlines in the editor buffer anymore
• Introduce helper function get_terminated_line() which adds the newline
• Now s/\z/NEW/ is interpreted the same as s/$/NEW/, i.e. append NEW to end of line
• Bump version number in case of regressions
• Removing the newlines from the editor buffer also reduces memory usage, but that is not the main intent of this patch

Test...

1. Null command

*1
#include <stdio.h>

2. List command w/lineno

*1,2ln
1	#include <stdio.h>$
2	#include <stdlib.h>$

3. Print command

*1p
#include <stdio.h>

4. Join command

*1,2j    
*1
#include <stdio.h>#include <stdlib.h>

5. Transpose (copy) command

*4n
4	int
*4t0
*1,2n
1	int
2	#include <stdio.h>#include <stdlib.h>

6. Move command

*1,2m$   
*$-2,$n 
42	} // ddd?s
43	int
44	#include <stdio.h>#include <stdlib.h>

7. Substitute command

*$
#include <stdio.h>#include <stdlib.h>
*s/include/exclude/g
*.
#exclude <stdio.h>#exclude <stdlib.h>

8. Delete command

*$d
*$=
43
*.
int

9. Insert command

*0i    
start of buffer
.
*1n 
1	start of buffer

10. Append command

*1a    
2ND LINE!!!!!
.
*1,2n
1	start of buffer
2	2ND LINE!!!!!

11. Change command

*1,2c
BEGIN buffer     
second line 
.
*1,2n
1	BEGIN buffer
2	second line

12. Undo command

*u
*1,2n
1	start of buffer
2	2ND LINE!!!!!

13. EDIT command

*E a.s
790
*1,3n
1		.arch armv6
2		.eabi_attribute 28, 1
3		.eabi_attribute 20, 1

14. Filename command

*f 
a.s

15. Read command (linux ifconfig prints and extra empty line)

*0r !ifconfig lo 
387
*.=
9

16. Write command

*1,15w !cat -n 
     1	lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
     2	        inet 127.0.0.1  netmask 255.0.0.0
     3	        inet6 ::1  prefixlen 128  scopeid 0x10<host>
     4	        loop  txqueuelen 1000  (Local Loopback)
     5	        RX packets 30  bytes 2892 (2.8 KiB)
     6	        RX errors 0  dropped 0  overruns 0  frame 0
     7	        TX packets 30  bytes 2892 (2.8 KiB)
     8	        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
     9	
    10		.arch armv6
    11		.eabi_attribute 28, 1
    12		.eabi_attribute 20, 1
    13		.eabi_attribute 21, 1
    14		.eabi_attribute 23, 3
    15		.eabi_attribute 24, 1
524

17. Regex prefix + Number command

*/main/n 
32		.global	main

18. Repeat search with empty regex

*//
	.type	main, %function

19. Mark command (current addr saved as x)

*.kx
*$
	.section	.note.GNU-stack,"",%progbits
*'xs/function/F_U_N_K_T_O_W_N/
*n
37		.type	main, %F_U_N_K_T_O_W_N

20. HelpMode command

*-1000000000000000000000
?
*H
invalid address
*-----------
	.ascii	"yo\000"
*yo
?
unknown command

[coveralls]

Pull Request Test Coverage Report for Build 13069671346

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.7%) to 73.389%

---

Totals
Change from base Build 13054078573:	-0.7%
Covered Lines:	353
Relevant Lines:	481

---

💛 - Coveralls

[briandfoy]

I don't know enough about ed, but is this how the other versions work? Specifically, if I use \z to anchor, the newline should still be there?

If tis patch makes it work like the other ed's, I'm fine with this. Typically you have compatibility notes in the PR, but not this time.

[mknos]

The \z match includes the newline, which was problematic because text could be substituted after the newline, which is supposed to terminate the line string.
Using \z is not compatible with other versions of ed because it is a perl-regex-ism.
For now this patch will avoid the problem of incorrectly splitting a line.
For greater compatibility I can make another patch to interpret \z as "z" and \Z as "Z" (similar to how "\n" is currently handled).

[briandfoy]

Ah, I get it now. Thanks for the clarification.