Re: [PATCH 1/2] gcore: improve shell use

[Simon Marchi <simark@simark.ca>]

On 3/29/25 7:42 PM, Keith Seitz wrote:
> Hi,
> 
> On 3/28/25 11:58 AM, Sam James wrote:
>> * Use bash tests, i.e. '[[' and ']]', instead of POSIX '[' and ']' or
>>    'test' which have their own pitfalls, given gcore has a bash shebang already.
>>
>> * Use $() subshell syntax rather than `backticks`.
> 
> Nice. I didn't actually know that '[['/']]' was preferred. I'll have
> to remember that.
> 
>> ---
>>   gdb/gcore-1.in | 22 +++++++++++-----------
>>   1 file changed, 11 insertions(+), 11 deletions(-)
>>
>> diff --git a/gdb/gcore-1.in b/gdb/gcore-1.in
>> index c0979a51db3..edd807b86dc 100644
>> --- a/gdb/gcore-1.in
>> +++ b/gdb/gcore-1.in
>> @@ -139,14 +139,14 @@ if test "x$binary_path" = x. ; then
>>       # The gcore script was not found in ".", which means the script
>>       # was called from somewhere else in $PATH by "sh gcore".
>>       # Extract the correct path now.
>> -    binary_path_from_env=`which "$0"`
>> -    binary_path=`dirname "$binary_path_from_env"`
>> +    binary_path_from_env=$(which "$0")
>> +    binary_path=$(dirname "$binary_path_from_env")
> 
> This uses 'which', and we've (downstream distros) run into issues
> with this and package dependencies. Since this strictly bash,
> can we use "command -v" here instead?

Can you clarify what kind of issues?  Do you mean that `which` may not
be available?

shellcheck points out this:

In gcore line 69:
        OPTARG="${OPTARG#'$OPT'}"
                         ^----^ SC2016 (info): Expressions don't expand in single quotes, use double quotes for that.

I actually can't figure out what this "if" does:

    if [[ "$OPT" = "-" ]]; then
	OPT="${OPTARG%%=*}"
	OPTARG="${OPTARG#'$OPT'}"
	OPTARG="${OPTARG#=}"
    fi

Any idea?

Simon