Another bad script (I ask again: me, my shell, or my lousy scripting?)

L_Carver · 12-15-2016, 03:07 AM

The one text file I give it to read, ASCII text (file command and "cat -e" both verify the line endings are right), gives me echo lines like

Code:

img_3832.jpg:PQL

It's not recognizing ":" as the field separator.

And it's not just my choice of separators. I've tried , and ^ with equal lack of success.

The script is below.

Code:

#!/bin/bash
SAVEIFS=$IFS
IFS=$(echo -en "\n\b")
set +xv

function gettext () {
echo -e "What annotations file will I be using?"
read -er thelist
#Allowing for, and correcting, the trailing space in interactive mode
if [[ "$thelist" ]]; then
	capfile1=${thelist% *}
else
	capfile1=$thelist
fi
}
gettext
while IFS=":" read -r file1 cate
do		echo -ne "$file1\n$cate\n"
		exiftool -fast5 -overwrite_original_in_place -q -P -IPTC:Category="$cate" -XMP:Category="$cate" "$file1"
		echo -ne "Written:\tCATEGORY"
done<"$capfile1"


IFS=$SAVEIFS

So what is it that I, my installed ShellCheck, and SC online aren't seeing?

Carver

L_Carver · 12-15-2016, 03:57 AM

More of my own work (a dog chasing its own tail, but I really want to solve this.):

Changing line 17 to

Code:

IFS=\: read -a file1 cate

merely causes the script to hang. So unless I'm wrong, it isn't the separator (or the way it's set) at all.

Using an identical read loop in terminal "echoes" the file name separate from the category listed. So where's the difficulty in the subshell seeing and USING the separator?

Carver

hydrurga · 12-15-2016, 04:17 AM

Comment removed...

pan64 · 12-15-2016, 05:14 AM

you still did not understand what was explained to you:
use set -xv at the beginning of the script to see what's happening. That will be a good help to understand the program flow.
use " to protect your variables: like capfile1="$thelist" otherwise they may be split
IFS=: IFS=\: and IFS=":" are the same

Quote:

It's not recognizing ":" as the field separator.

is definitely not the right deduction, this is just a visible "side effect".
shellcheck will not find logical errors...

MadeInGermany · 12-15-2016, 01:13 PM

Maybe you have two or more : in a row, then you need an additional variable to catch the remainder.

Code:

while IFS=":" read -r file1 cate junk

--
bash knows "$ quoting":

Code:

IFS=$'\n\b'

--
"gettext" is an unlucky name for a function because it can be confused with the gettext program.

L_Carver · 12-16-2016, 05:02 PM

Quote:

Originally Posted by MadeInGermany

"gettext" is an unlucky name for a function because it can be confused with the gettext program.

Thank you for pointing that out. I think I intuited 'gettext' from the (remarkably old) Mac Hypercard term getfile, aka Open dialogs. I'll intuit something else instead. I use silly things like "hotdog" and "hamburger" for other variables and functions, so it'd be advisable to tap my sense of humour here too, I suppose.

Carver