hello .. On Fri, May 19, 2023, 16:29 Chet Ramey <chet.ra...@case.edu> wrote:
> On 5/18/23 10:14 PM, Dale R. Worley wrote: > > Chet Ramey <chet.ra...@case.edu> writes: > >> Bash allows the close brace to be joined to the remaining > >> characters in the word without being followed by a shell metacharacter > >> as a reserved word would usually require. > > > > I had to read this a couple of times to figure out what it means. In > > particular "the word" isn't well-bound here. > > Command substitution is a word expansion; word expansions are performed on > words; command substitution occurs as part of a word. That all seems > self-evident. The only reason to mention it is the quirk required to have > the close brace act as a reserved word when it is needed to terminate the > command (you know someone will eventually ask about it). > why this > This text is clear in its description of the behavior but entirely > > unclear regarding what the point is: > > > >> If the first character is a '|', the construct expands to the value of > >> the 'REPLY' shell variable after COMMAND executes, without removing any > >> trailing newlines, and the standard output of COMMAND remains the same > >> as in the calling shell. > > What's mysterious about it? If you don't want to have to output text as > the value of the command substitution, you can simply assign arbitrary > data to REPLY. The bonus is that the trailing newlines are preserved, a > common question about standard command substitution. > very good 1:1 data is upper depend > My guess is that the intention is for COMMAND to be "read" with no > > names: > > Not necessarily. The example shows a simple assignment to REPLY. > > > Also, can you clarify the semantics on this point: The text above says > > "the construct expands to the value of the 'REPLY' shell variable after > > COMMAND executes, without removing any trailing newlines". However, the > > documentation of "read" says: "If no names are supplied, the line read, > > without the ending delimiter but otherwise unmodified, is assigned to > > the variable REPLY." > > The two uses are unrelated. > > > So the sequence of processing is: read inputs a line; read deletes the > > ending newline and assigns the remainder to REPLY; command substitution > > obtains the value of REPLY (which does not contain a newline); command > > substitution returns that value "without removing any trailing > > newlines". > > > > Is that what you intend the code to do/what the code does? > > No. I mean, if you want to use `read' in that way, you certainly can, but > that's not going to be the common case. > > Chet > > -- > ``The lyf so short, the craft so long to lerne.'' - Chaucer > ``Ars longa, vita brevis'' - Hippocrates > Chet Ramey, UTech, CWRU c...@case.edu http://tiswww.cwru.edu/~chet/ > > >
