In Parameter Expansions / Case Modification:
[S1]
The first sentence reads, "alphabetic characters," which can imply that
wherever else in the paragraph the word "characters" is used, that the
intended meaning is "alphabetic characters," which is not the case. It can
be read as something like a declaration of a specific conversation topic.
This multiplicity of meaning in a single word, "characters," can be thought
of as similar to a namespace collision.
[S3]
The third sentence makes no distinction between alphabetic characters and
ASCII characters, although in practice such a distinction exists.
$ yy='./scripts_install-ups'
$ echo ${yy^s}
./scripts_install-ups
$ yy='scripts_install-ups'
$ echo ${yy^s}
Scripts_install-ups
The third sentence could read more clearly with the inclusion of one
word: "ASCII" (changes are underlined).
Before:
3) Each character in the expanded value of parameter is tested against
pattern, and, if it matches the pattern, its case is converted.
After:
3) Each _ASCII_ character in the expanded value of parameter is tested
against pattern, and, if it matches the pattern, its case is converted.
Without the inclusion of the word "ASCII," sentence three (as well as
sentence six, below) can easily be read incorrectly as applying only to
"alphabetic characters" as a result of the implied topic declaration in
sentence one.
[S5]
Sentence five speaks of "the ^ operator" and "the , operator" - however
this use of English language is again unclear. There are four meaningful
syntactical forms involved in this Parameter Expansion:
, ^ ,, ^^
They are composed of varying combinations of two raw constituent ASCII
characters:
, ^ (\x2c and \x5e)
There's an overlap, when the text reads, "the ^ operator" it can be read
as referring to either a specific and meaningful syntactical form, (^), or
a raw constituent ASCII character, (^). It appears that the latter meaning
is intended. Otherwise, the descriptions would contradict each other of the
single-character PE operators in both sentence five and the second half of
sentence six. Elsewhere in the manual the word "operator" is also used.
>From a partial search, it appears that the word tends to be used much more
often to refer to specific meaningful syntactical forms rather than raw
ASCII characters.
declare -a control_operators=( [0]="||" [1]="&" [2]="&&" )
declare -a parameter_transformation_operators=( [0]="U" [1]="u" [2]="L"
)
Sentence five could read more clearly as (changes underlined):
Before:
5) The ^ operator converts lowercase letters matching pattern to
uppercase; the , operator converts matching uppercase letters to lowercase.
After:
5) The _operators_ _containing_ _ASCII_ _^_ _characters_ _convert_
lowercase letters matching pattern to uppercase, and _operators_
_containing_ _ASCII_ _,_ _characters_ convert matching uppercase letters to
lowercase.
[S6]
Sentence six could benefit from a change similar to that of sentence
three.
Before:
6) The ^^ and ,, expansions convert each matched character in the
expanded value; the ^ and , expansions match and convert only the first
character in the expanded value.
After:
6) The ^^ and ,, expansions convert each matched character in the
expanded value; the ^ and , expansions match and convert only the first
_ASCII_ character in the expanded value.
I hope this suggestion helps.
cHEERS,
Wiley
