Re: Conditional operator in Shell Arithmetic section

[Lawrence Velázquez]

On Sat, Mar 18, 2023, at 1:59 PM, uzibalqa wrote:
> Have been reading the manual about the arithmetic conditional operation 
> described by 
>
> expr ? expr : exp
>
> This is quite difficult to understand exactly how to use it.

I'm sure there are ample C examples out there.


> For instance, consider setting the variable opst to 0 when the length 
> of delim in positive in a bash script.  One would use 
>
> opst=$(( ${#delim} > 0 ? 0 : 1 ))

Or:

        if [[ -n $delim ]]; then
            opst=0
        else
            opst=1
        fi

or:

        [[ -n $delim ]]
        opst=$?

or:

        opst=$((${#delim} < 1))

or:

        opst=$((! ${#delim}))

As Greg said, if you don't understand the operator, don't use it.
You have other options.

    
> There needs to be at least one example of actual use in a typical 
> situation.

No, there doesn't.


> I also suggest to include it in section "3.2.5.2 
> Conditional Constructs".

It's already in Section 6.5.  It does not belong in 3.2.5.2.


> Specifying conditional operator "expr ? expr : exp"  simply as Shell 
> Arithmetic makes it very difficult to find in the manual.

The index could be a little more comprehensive, I guess.


-- 
vq