#688 Issue `closed`: In DEBUGSCRIPTS mode print shell input lines as they are read?¶

Labels: enhancement, documentation, fixed / solved / done

jsmeix opened issue at 2015-11-11 12:11:¶

Currently when in DEBUGSCRIPTS mode only "set -x" is done.

Personally I prefer "set -vx" when debugging bash scripts because
'-v' prints the script source code lines (in chunks as read by bash) and afterwards '-x' prints the commands and their arguments as they are executed.

For me this makes debugging issuse very much faster because I see first the original source code lines and then what commands and arguments the bash eveluation results which helps me very much to understand what is actually happening.

Hereby I request that in DEBUGSCRIPTS mode "set -vx" is done.

I propose the following in usr/share/rear/lib/framework-functions.sh
(plus some explanatory comments):

function Source() {
...
    # in DEBUGSCRIPTS mode print shell input lines as they are read
    # and print commands and their arguments as they are executed:
    test "$DEBUGSCRIPTS" && set -vx
    # the actual work (source the source file):
    Debug "Begin sourcing '$source_file'"
    . "$source_file"
    Debug "End sourcing '$source_file'"
    # undo DEBUGSCRIPTS mode settings:
    test "$DEBUGSCRIPTS" && set +vx

If you like it, I make a pull request.

schlomo commented at 2015-11-11 12:59:¶

:-) I know the -v feature and it always confused me to see almost the same content twice... In my Bash debugging needs so far -v played a seldom and minor role. I sometimes add : $VAR in the code to see the content of a variable in -x mode.

Question: Is it a matter of taste? Should we allow configuration for this?

jsmeix commented at 2015-11-11 13:11:¶

@schlomo
just propose what rear command line parameter you like
for "set -v" and I will implement it.

Perhaps a command line parameter '-C' for "Code"
or something like that?

jsmeix commented at 2015-11-11 13:14:¶

Or perhaps even better add support for a value for the '-D'
parameter where the value is by default 'x' like:

rear -D

results "set -x" and

rear -D vx

results "set -vx"

and

rear -D v

results "set -v".

This way - for debugging by experts - even

rear -D xvue

could be set.

schlomo commented at 2015-11-11 13:58:¶

I think I prefer -D and -DD, interpreting -v as an additional verbosity
layer on top of -x.

What do you think?

On 11 November 2015 at 14:14, Johannes Meixner notifications@github.com
wrote:

Or perhaps even better add support for a value for the '-D'
parameter where the value is by default 'x' like:

rear -D

results "set -x" and

rear -D vx

results "set -vx"

and

rear -D v

results "set -v".

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Reply to this email directly or view it on GitHub
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gdha commented at 2015-11-11 14:34:¶

We already have verbose (-v). Why don't use this as a trigger for set -x$v ? Keep it simple no?
Gratien

Verstuurd vanaf mijn iPhone

Op 11 nov. 2015 om 14:58 heeft Schlomo Schapiro notifications@github.com het volgende geschreven:

I think I prefer -D and -DD, interpreting -v as an additional verbosity
layer on top of -x.

What do you think?

On 11 November 2015 at 14:14, Johannes Meixner notifications@github.com
wrote:

Or perhaps even better add support for a value for the '-D'
parameter where the value is by default 'x' like:

rear -D

results "set -x" and

rear -D vx

results "set -vx"

and

rear -D v

results "set -v".

—
Reply to this email directly or view it on GitHub
https://github.com/rear/rear/issues/688#issuecomment-155783148.

—
Reply to this email directly or view it on GitHub.

schlomo commented at 2015-11-11 16:46:¶

@gdha brilliant idea - thanks a lot for seeing the simple things!

On 11 November 2015 at 15:34, gdha notifications@github.com wrote:

We already have verbose (-v). Why don't use this as a trigger for set -x$v
? Keep it simple no?
Gratien

Verstuurd vanaf mijn iPhone

Op 11 nov. 2015 om 14:58 heeft Schlomo Schapiro <
notifications@github.com> het volgende geschreven:

I think I prefer -D and -DD, interpreting -v as an additional verbosity
layer on top of -x.

What do you think?

On 11 November 2015 at 14:14, Johannes Meixner <notifications@github.com

wrote:

Or perhaps even better add support for a value for the '-D'
parameter where the value is by default 'x' like:

rear -D

results "set -x" and

rear -D vx

results "set -vx"

and

rear -D v

results "set -v".

—
Reply to this email directly or view it on GitHub
https://github.com/rear/rear/issues/688#issuecomment-155783148.

—
Reply to this email directly or view it on GitHub.

—
Reply to this email directly or view it on GitHub
https://github.com/rear/rear/issues/688#issuecomment-155798687.

jsmeix commented at 2015-11-12 15:35:¶

Only a note FYI:

For now I cannot work on it because a customer printing issue
appeared.

Using '-v' plus '-D' to get "set -vx" is o.k. for me
but it is not really KISS as I understand what KISS means.

Using '-v' plus '-D' to get "set -vx" is RFC 1925 (5)
from my point of view.

And the result is a backward incompatible change
because before '-v' and '-D' were separated things.

Personally I prefer a variant of KISS:
KSIS: Keep Separated Issues Separated.

But I do not want to make a longer discussion
because of this relatively small issue.

I will implement using '-v' plus '-D' to get "set -vx".

Probably I will also implement that '-D' can have an
optional value because I like to be able to "set -xue"
via '-D xue' for my own personal needs...

pavoldomin commented at 2015-11-12 19:46:¶

Indeed, it's not the best thing if the cmdline options behavior change: e.g. we could expect much bigger logfile on systems where 'rear -v -D' is scheduled (potentially affecting a filesystem utilization).

jsmeix commented at 2015-11-13 14:48:¶

I made a first tentative and currentyl untested implementation
by using a separeated long option --debugscripts that
requires an argument where the argument contains
the flags to be 'set' so thet e.g. '--debugscripts=xv'
results 'set -xv'.

I need to play around with it how it works.

If you like to have a look see
https://github.com/jsmeix/rear/tree/add_optional_value_to_specify_D_command_line_option_settings

jsmeix commented at 2015-11-18 15:33:¶

It happened while working on this issue that I did much more than I actually intended which results the big pull request https://github.com/rear/rear/pull/699

jsmeix commented at 2015-11-18 16:16:¶

Regarding make rear working with ''set -ue -o pipefail"
I created https://github.com/rear/rear/issues/700

jsmeix commented at 2015-11-20 08:58:¶

This issue is fixed by https://github.com/rear/rear/pull/699 via a new debugscripts option which is fully backward compatible because the behaviour of the other options does not change.

Now one can use e.g.

rear --debugscripts xv mkbackup

or even things like

rear --debugscripts 'xvue +h -o pipefail' help

jsmeix commented at 2015-11-20 13:51:¶

I need to update the man page as well, cf. https://github.com/rear/rear/issues/700#issuecomment-158338328

jsmeix commented at 2015-12-02 09:02:¶

With the added documentation for the new debugscripts option in https://github.com/rear/rear/issues/715 this issue is fixed.

[Export of Github issue for rear/rear.]

#688 Issue closed: In DEBUGSCRIPTS mode print shell input lines as they are read?¶