Recent changes to 62: hook.sh syntax error at line 285

#62 hook.sh syntax error at line 285

Rocky Bernstein — Mon, 07 Oct 2019 23:35:14 -0000

On Mon, Oct 7, 2019 at 3:04 PM tien ho van hvtien.ch@gmail.com wrote:

Hi Rocky,

I just saw your patch this morning, applied it and tested again. It resolved my problems. I think your idea to put it to read only is great, really very good, because is more reliable and we don't need to executed this.
Therefore I think we need also to delete the following line too, which I put actually in comment.

_Dbg_hook_enter_debugger() {
_Dbg_stop_reason="$1"
[[ 'noprint' != $2 ]] && _Dbg_print_location_and_command
_Dbg_process_commands
_Dbg_set_to_return_from_debugger 1 # Persist the user-space value of BASH_REMATCH in user space # eval $_Dbg_last_regmatch_command
return $_Dbg_continue_rc
}

I already tested it.

I am not totally sure what you mean, but when 'eval $_Dbg_last_regmatch_command" is commented out, then BASH_REMATCH might not be not set properly on debugger exit.
As a result a program like this:

regex='aa(b{2,3}[xyz])cc'
for word in aab aabbxcc aabbcc; do
    if [[ $word =~ $regex ]]; then
        echo "$word matches"
        i=1
        n=${#BASH_REMATCH[*]}
        while [[ $i -lt $n ]]
        do
            echo "  capture[$i]: ${BASH_REMATCH[$i]}"
            let i++
        done
    else
        echo "$word does not match"
    fi
    shift
done

Will not work properly when it is stepped through.

If I can help you, just let me know.

What would be a big help would be to write a test case that incorporates both bash scripts that might fail: the one that you started with and the one I just gave.

Thanks for all the help.

#62 hook.sh syntax error at line 285

Rocky Bernstein — Thu, 03 Oct 2019 16:21:31 -0000

Commit #57b18c2 might fix things. Please double check though.

This is about all the time in the near future I'll be able to spend on this. In case you want to improve or work up a regression test based on your test, here is what was going on.

We need to save and BASH_REMATCH going into the debugger and restore it leaving so that if the debugged program uses that variable it has the value it set rather than something the debugger might have set.

hook.sh syntax error at line 285

Wybo — Thu, 03 Oct 2019 11:56:56 -0000

# bash --version
GNU bash, version 5.0.3(1)-release (x86_64-pc-linux-gnu)

# bashdb --version
bashdb, release 5.0-1.1.0

# cat bashdb-test
#!/bin/bash
line='= asd'
if [[ "$line" =~ ^=\ (.*) ]]; then 
   echo yes
else
   echo no
fi
echo bye

When I bashdb on this file and type next trhee times I get this error mesaage:

/usr/share/bashdb/lib/hook.sh: eval: line 285: conditional binary operator expected
/usr/share/bashdb/lib/hook.sh: eval: line 285: syntax error near `asd'
/usr/share/bashdb/lib/hook.sh: eval: line 285: `[[ = asd =~ ^=\ (.*) ]]'

although everything else runs as expected.