Been a long time: another broken script

L_Carver · 11-15-2020, 08:21 PM

These commands

Code:

cap=$(exiv2 -g Iptc.Application2.Caption  -Pv "$fg")
	if [[ -f "$cap" ]]; then
		echo -e "$fg \e[1mhas\e[0m a Caption."
	clen=${#cap}
	echo -e "The caption for $fg is $clen characters long (spaces included)."
	echo -e "$fg:\\t$clen" >> captionlengths.txt
	fi

work when C&P'd (cut and pasted), but not when run as a script (see attached).
(Aside: I'm too much of a cheesehead nowadays to learn printf without having a book like the ABS, sorry about that.)

As usual, please advise corrections (preferably using echo's, .)
Oh and my DM is now Kubuntu 20.04 and change (whatever the latest maint. upgrade is).

Carver

berndbausch · 11-15-2020, 08:25 PM

It would help enormously if you stated what you expect from the script and what happens when you run it as a script. The attached file doesn't show anything failing.

Also, I doubt the meaning of C&P is clear to everybody (not to me anyway), so you may want to clarify that.

L_Carver · 11-15-2020, 11:03 PM

Quote:

Originally Posted by berndbausch

It would help enormously if you stated what you expect from the script and what happens when you run it as a script. The attached file doesn't show anything failing.

Also, I doubt the meaning of C&P is clear to everybody (not to me anyway), so you may want to clarify that.

My issue is, when I run it, the script hangs and doesn't echo the length of each caption or write the text file (at all). I get that when I cut and paste line 20, but again, not when the script runs.

I hope that explains what I'm looking for help with.

Carver

berndbausch · 11-15-2020, 11:55 PM

Have you tried running the script with the -x option? E.g. bash -x nameofyourscript. It outputs the details of each command it executes.

If the script doesn't execute the echo's, I would assume that there is no file named $cap and investigate why. When you leave the echo $fg in, is the output as expected?

ondoho · 11-16-2020, 12:55 AM

The attached file and the code you pasted are not identical; how would they give the same results?
I don't understand what you're getting at.
What if you reduce the script to the exact same code that works when "C&P"'d on the command line?
How can it even work on the command line when $fg isn't defined?

Please always show us actual output of actual commands ("C&P" the terminal output) instead of praphrasing.

pan64 · 11-16-2020, 01:17 AM

cap is not a file (if I understand well) so [[ -f $cap ]] is just wrong.
but as it was already told: we cannot suggest you anything if we have no idea: what is it all about.

rnturn · 11-16-2020, 01:08 PM

Quote:

Originally Posted by pan64

cap is not a file (if I understand well) so [[ -f $cap ]] is just wrong.
but as it was already told: we cannot suggest you anything if we have no idea: what is it all about.

And what is the script supposed to do if "$cap" doesn't refer to a file? Or is a null string?

I'd suggest the OP's coding be more defensive and issue error messages when bad/incorrect data is encountered (which could very be the norm and not the exception) rather than simply forging ahead and feeding it into the rest of the script where weird errors can occur.

Something like:

Code:

if [ -z "$cap" ]; then
    echo "FATAL: You must specify a file!"
    RC=1
else
    if [ ! -f "$cap" ]; then
        echo "FATAL: \"$cap\" is NOT a file!"
        RC=1
    else
        #
        # Do something using the file...
        #
        ...
        RC=0 (unless other errors occur)
    fi
fi
exit $RC

as a start. Too much code gets written as though nothing will ever fail. Burns you every time.

boughtonp · 11-16-2020, 03:02 PM

Quote:

Originally Posted by rnturn

And what is the script supposed to do if "$cap" doesn't refer to a file? Or is a null string?

You've misread something.

What the script appears to be attempting is appending a list of image filenames and caption lengths to a file, but only when the caption contains a value.

What Pan is saying is that the command "[font=monospace]cap/font]" is populated from doesn't give a filename - it gives IPTC Caption metadata - and nothing in the rest of the script implies that caption contains anyhting other than just text, so the file test is most likely meaningless, and (based on the then output) should probably be -n instead.

Another problem with the script is using "white read fg" when it should probably be "while IFS= read -r fg" (or similar).