#45 set args is flawed when one parameter is an array

[Jean-christophe Manciot]

Considering the following script which accepts 2 parameters:
+ files_list which is expected to be an array
+ command which is expected to be a string

1 2 3 4 5

#!/bin/bash shopt -s extglob files_list=$1 command=$2

1) First method: passing the array when calling bashdb

# bashdb /usr/bin/.drive-format-driveinclude -- files_to_push pushbash debugger, bashdb, release 4.4-0.92

Copyright 2002, 2003, 2004, 2006-2012, 2014, 2016 Rocky Bernstein
This is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.

(/usr/bin/.drive-format-driveinclude:55):
55: shopt -s extglob
bashdb<0> s
(/usr/bin/.drive-format-driveinclude:59):
59: files_list=$1
bashdb<1> s
(/usr/bin/.drive-format-driveinclude:60):
60: command=$2
bashdb<2> s
(/usr/bin/.drive-format-driveinclude:62):
62: section='out'
bashdb<3> x files_list
declare -- files_list="--"
bashdb<4> x $command
files_to_push
bashdb<5> 

As we can see here, both parameters are wrongly set.

2) Second method: setting the array inside bashdb with set args

# bashdb /usr/bin/.drive-format-driveinclude 
bash debugger, bashdb, release 4.4-0.92

Copyright 2002, 2003, 2004, 2006-2012, 2014, 2016 Rocky Bernstein
This is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.

(/usr/bin/.drive-format-driveinclude:55):
55: shopt -s extglob
bashdb<0> set autoeval on
Evaluate unrecognized commands is on.
bashdb<1> files_to_push=([0]="CVs/Consultant Réseaux.odt" [1]="CVs/Consultant Réseaux.pdf" [2]="CVs/Ingénieur Réseaux.odt" [3]="CVs/Ingénieur Réseaux.pdf" [4]="CVs/Network & Security Engineer.odt" [5]="CVs/Network & Security Engineer.pdf")
$? is 0
bashdb<2> x files_to_push
declare -a files_to_push=([0]="CVs/Consultant Réseaux.odt" [1]="CVs/Consultant Réseaux.pdf" [2]="CVs/Ingénieur Réseaux.odt" [3]="CVs/Ingénieur Réseaux.pdf" [4]="CVs/Network & Security Engineer.odt" [5]="CVs/Network & Security Engineer.pdf")
bashdb<3> seta args /usr/bin/.drive-format-driveinclude files_to_push push
/tmp/bashdb_eval_32703: line 2: seta: command not found
$? is 127
bashdb<4> s
(/usr/bin/.drive-format-driveinclude:59):
59: files_list=$1
bashdb<5> s
(/usr/bin/.drive-format-driveinclude:60):
60: command=$2
bashdb<6> s
(/usr/bin/.drive-format-driveinclude:62):
62: section='out'
bashdb<7> x files_list
declare -- files_list=""
bashdb<8> x $command

bashdb<9> 

As we can see again here, both parameters are wrongly set.

One workaround is to set the parameters directly after the first lines with:

bashdb<9> files_list=([0]="CVs/Consultant Réseaux.odt" [1]="CVs/Consultant Réseaux.pdf" [2]="CVs/Ingénieur Réseaux.odt" [3]="CVs/Ingénieur Réseaux.pdf" [4]="CVs/Network & Security Engineer.odt" [5]="CVs/Network & Security Engineer.pdf")
$? is 0
bashdb<10> command=push
$? is 0
bashdb<11> 

[Jean-christophe Manciot]

It does not appear in the post above, but "files_to_push" is of course set before calling bashdb in the first method:

# files_to_push=([0]="CVs/Consultant Réseaux.odt" [1]="CVs/Consultant Réseaux.pdf" [2]="CVs/Ingénieur Réseaux.odt" [3]="CVs/Ingénieur Réseaux.pdf" [4]="CVs/Network & Security Engineer.odt" [5]="CVs/Network & Security Engineer.pdf")

[Rocky Bernstein]

I don't see what this has to do with arrays. I think bashdb is just confused by the '--' which is getting set as $1. The -- should be detected and removed.

So a workaround for now is to not use -- in those cases where it is not needed. It is needed when options to the program might be confused with options to bashdb

Again since it will take me a while to have time to fix this, feel free to use this information to work up a patch.

[Jean-christophe Manciot]

As a matter of fact, my script is not correct: I over-evaluated bash simplicity to pass arguments.

The right way to pass an array parameter to a script is as follows:

declare -a **files_list=("$@")**

So, now everything is fine when used with bashdb (without "--"):

bashdb /usr/bin/.drive-format-driveinclude **"${files_to_push[@]}"** push

bash debugger, bashdb, release 4.4-0.92
...
(/usr/bin/.drive-format-driveinclude:55):
55: shopt -s extglob
bashdb<0> set autoeval on
Evaluate unrecognized commands is on.
bashdb<1> s
(/usr/bin/.drive-format-driveinclude:59):
59: declare -a files_list=("$@")
bashdb<2> s
(/usr/bin/.drive-format-driveinclude:60):
60: command=$2
bashdb<3> s
(/usr/bin/.drive-format-driveinclude:62):
62: section='out'
bashdb<4> x files_list
declare -a files_list=([0]="CVs/Consultant Réseaux.odt" [1]="CVs/Consultant Réseaux.pdf" [2]="CVs/Ingénieur Réseaux.odt" [3]="CVs/Ingénieur Réseaux.pdf" [4]="CVs/Network & Security Engineer.odt" [5]="CVs/Network & Security Engineer.pdf" [6]="push")
bashdb<5> 

You can mask this post as "Not a bug"

[Rocky Bernstein]

93d8abd addresses the bug where bashdb was getting confused by -- in setting arguments.