[Nottingham] Bash script problem

[Ron Wilton]

Hello everyone

I've written the following bash script.

#
for file in *.jpg ; do

    # creating the thumbnail filename
    thumbfile="$(basename "$file" .jpg)th.jpg"

    # reading the width and height of the jpg
    let WIDTH=exiftags $file | grep "Image Width"
    let HEIGHT=exiftags $file | grep "Image Height"

    if [ WIDTH > HEIGHT ] ; then
        # convert as landscape
        convert -thumbnail 200x150 "$file" thumbnails/"$thumbfile"
    else
        # convert as portrait
        convert -thumbnail 150x200 "$file" thumbnails/"$thumbfile"
    fi

done
#

and even though it does what I want (ie create thumbnails of jpg files in the correct landscape/portrait orientation) I get the following errors:-

profam: line 20: let: 20080720-142448.jpg: syntax error: invalid arithmetic operator (error token is ".jpg")
profam: line 21: let: 20080720-142448.jpg: syntax error: invalid arithmetic operator (error token is ".jpg")

(where line 20 is the 'let WIDTH=exiftags...' line, and 'profam' is the name of my bash script).



I've tried the following changes, which also produces errors.

1) removed the let
    WIDTH=exiftags $file | grep "Image Width"
    HEIGHT=exiftags $file | grep "Image Height"

errors:-
profam: line 20: 20080720-142448.jpg: command not found
profam: line 21: 20080720-142448.jpg: command not found



2) added '$'
    WIDTH=exiftags $file | grep "Image Width"
    HEIGHT=exiftags $file | grep "Image Height"

    if [ $WIDTH > $HEIGHT ] ; then

errors:-
profam: line 20: 20080720-142546.jpg: command not found
profam: line 21: 20080720-142546.jpg: command not found
profam: line 23: 1: ambiguous redirect



3) put the 'let' back in
    let WIDTH=exiftags $file | grep "Image Width"
    let HEIGHT=exiftags $file | grep "Image Height"

    if [ $WIDTH > $HEIGHT ] ; then

errors:-
profam: line 20: let: 20080720-142546.jpg: syntax error: invalid arithmetic operator (error token is ".jpg")
profam: line 21: let: 20080720-142546.jpg: syntax error: invalid arithmetic operator (error token is ".jpg")
profam: line 23: 1: ambiguous redirect


Can anyone see what I'm doing wrong?

Thanks for any help

Ron





      
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