better grammar with $#

better grammar with $#

[Ray Andrews]

[-- Attachment #1: Type: text/plain, Size: 845 bytes --]


     output=$( eval "$@" )  # Input here is a 'find' command outputting 
a list of files.
     tmp=( ${(f)output} )   # Count lines not characters.
     linecount=$#tmp

... it seems clumsy to create 'tmp' just to count lines, can that be a 
bit more streamlined?  And is it lines or words there?  The output is 
filenames so words=lines in this case but maybe not in other cases so 
I'd like to be sure to have a count of lines.  Easy to get one's 
splitting wrong.


BTW the ultimate in minutiae but the manual says:

12 Conditional Expressions

A /conditional expression/ is used with the [[ compound command to test 
attributes of files and to compare strings. Each expression can be 
constructed from one or more of the following unary or binary expressions:

... and AFAICT the tests work fine with the single '[' as well.

[-- Attachment #2: Type: text/html, Size: 1165 bytes --]

Re: better grammar with $#

[Philippe Troin]

[-- Attachment #1: Type: text/plain, Size: 623 bytes --]

On Sun, 2022-10-30 at 07:16 -0700, Ray Andrews wrote:
> 
>     output=$( eval "$@" )  # Input here is a 'find' command
> outputting a list of files.
>     tmp=( ${(f)output} )   # Count lines not characters.
>     linecount=$#tmp
> ... it seems clumsy to create 'tmp' just to count lines, can that be
> a bit more streamlined?  And is it lines or words there?  The output
> is filenames so words=lines in this case but maybe not in other cases
> so I'd like to be sure to have a count of lines.  Easy to get one's
> splitting wrong.

How about:
   linecount=${#${(f)"$(eval "$@")"}}

Phil.


[-- Attachment #2: Type: text/html, Size: 1058 bytes --]

Re: better grammar with $#

[Roman Perepelitsa]

On Sun, Oct 30, 2022 at 3:17 PM Ray Andrews <rayandrews@eastlink.ca> wrote:
>
>
>     output=$( eval "$@" )  # Input here is a 'find' command outputting a list of files.
>     tmp=( ${(f)output} )   # Count lines not characters.
>     linecount=$#tmp

You can combine the two expansions:

  linecount=${#${(f)output}}

> And is it lines or words there?

It's lines.

If you can replace the `find` command with a glob, it'll be simpler.
You'll also avoid quoting issues. If your code is supposed to handle
all sorts of file names, make sure it can handle files with backslash
and line feed in their names.

Roman.

Re: better grammar with $#

[Ray Andrews]

On 2022-10-30 10:29, Roman Perepelitsa wrote:
>
> You can combine the two expansions:
>
>    linecount=${#${(f)output}}

Nuts, I came close I tried: $#{${(f)output}}

If you can replace the `find` command with a glob, it'll be simpler.

Yeah, I'm migrating in that direction already.

> You'll also avoid quoting issues. If your code is supposed to handle
> all sorts of file names, make sure it can handle files with backslash
> and line feed in their names.

God knows.  I tend to crash into problems like that when they happen and 
deal with it at the time.  I wish there was some option to protect 
strings from all such issues, all the time, everywhere.


>
> Roman.
>