A Selected List of Additions and Changes Coming With POSIX Issue 8

posix-issue8.md

A Selected List of Additions and Changes Coming With POSIX Issue 8

Last major change: 10th March 2023

See Also: http://mywiki.wooledge.org/POSIX#Utilities

New Commands

• timeout
• realpath / readlink

Additions

Utility	Change	Usage
sh	Dollar Single Quotes	$'\n'
	Pipefail	set -o pipefail
	case Fallthrough	case ... in ...) ... ;&
	New test Expressions	<, >, -nt, -ot and -ef
	Support Delimited read	read -d ''
	Glob .* May Exclude dot and dot-dot [1]	for dotfiles in .*
	Dynamic fd Allocation	exec {var} > file
	Brace Expansion [1]	{start..end}, {a,b,c}
trap	Include the Default trap Conditions	-p
stty	Provide size, rows and cols	stty size; stty cols 80
rm	Verbose Flag	-v
	Explicit rmdir Functionality	-d
cd	Exit if Current Working Directory Cannot be Determined	-e
	Empty Argument is Now an Error	cd ''
sed	Support Extended Regular Expressions	-E
	Case Insensitive Substitution	sed 's/CaSe/insensitive/i'
awk	Return the Number of Array Elements with length()	length(array)
	Add fflush() Function	fflush()
	Add nextfile Statement	nextfile
	The delete Statement Now Deletes Entire Array	delete array
	Seed Value Unspecified if rand is Issued Before srand
date	Seconds Since Epoch	date +%s
tail	Reverse Order	-r
head	Count in Bytes	-c
printf	Gettext C-Format for Re-ordering Format Specifiers	printf '%1$s has some number %2$d\n'
find	Null Terminated Output	-print0
ps	Wide Output	-w
dd	Read Until EOF or Block Size is Reached	dd iflag=fullblock
xargs	Null Terminated Input	-0
	No Execution With Empty Input	-r
make	Support Indirect Expansion of Macros	$(indirect_$(expansion))
	Add .PHONY Target	.PHONY:
	Support Multiple Files with include	include foo.mk bar.mk baz.mk
	Allow Include Failures	-include might-not-exist.mk
	Allow Hyphens in Macro Names	hyphen-in-macro-name = allowed
	Allow Slashes in Target Names	foo/bar.o: foo/bar.c
	Add Pattern Substitution	$(foo:%.o=%.c)
	Non-Recursive Macro Assignment (GNU Style)	::=
	Non-Recursive Macro Assignment (BSD Style)	:::=
	Optional Macro Assignment	?=
	Appending Macro Assignment	+=
	Shell Command Macro Assignment	!=
	Add CURDIR Macro	CURDIR
	Provide the $^ Internal Macro	$^
	Provide the $+ Internal Macro	$+
	Support Parallelism	-j
	Dynamic Rebuilding of Included Files [1]
	Add .NOTPARALLEL and .WAIT Special Targets	foo: one .WAIT two
tsort	Allow Exit Status to Count Number of Cycles if Any Encountered	-w
mailx	Reject Sending Empty Messages	-E
bc	Allow Functions to Accept Arrays in Last Argument Position	define w(l a[])
logger	Add -f file, -i, -p priority, -t tag

Footnotes

Footnotes

1. These features are at the implementation's discretion and not required by the standard. ↩

mktemp has only just been proposed. It hasn't been approved and there's no draft spec. There hasn't been any progress on it in a while.

Yes, I must have mistook the "Desired Action" as the accepted text. Thanks, I'll remove it for now and hope it can be added back eventually.

Due to conflicting opinions on the ticket it appears that test did not gain a ==, as despite being part of the desired action, it's not in the final accepted text. More generally it was split out into its own proposal at https://austingroupbugs.net/view.php?id=762

I see it now, will remove ==