In /usr/bin/shrink_width line 7:
name=$0
^--^ SC2034: name appears unused. Verify use (or export if used externally).


In /usr/bin/shrink_width line 8:
bname=`basename $0`
      ^-----------^ SC2006: Use $(...) notation instead of legacy backticked `...`.
                ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
bname=$(basename "$0")


In /usr/bin/shrink_width line 15:
inwidth=`$VIPSHOME/bin/vips im_header_int Xsize $1`
        ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.
         ^-------^ SC2086: Double quote to prevent globbing and word splitting.
                                                ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
inwidth=$("$VIPSHOME"/bin/vips im_header_int Xsize "$1")


In /usr/bin/shrink_width line 16:
factor=`(echo scale=10; echo $inwidth / $3) | bc`
       ^-- SC2006: Use $(...) notation instead of legacy backticked `...`.
                             ^------^ SC2086: Double quote to prevent globbing and word splitting.
                                        ^-- SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
factor=$((echo scale=10; echo "$inwidth" / "$3") | bc)


In /usr/bin/shrink_width line 18:
$VIPSHOME/bin/vips im_shrink $1 $2 $factor $factor
^-------^ SC2086: Double quote to prevent globbing and word splitting.
                             ^-- SC2086: Double quote to prevent globbing and word splitting.
                                ^-- SC2086: Double quote to prevent globbing and word splitting.
                                   ^-----^ SC2086: Double quote to prevent globbing and word splitting.
                                           ^-----^ SC2086: Double quote to prevent globbing and word splitting.

Did you mean: 
"$VIPSHOME"/bin/vips im_shrink "$1" "$2" "$factor" "$factor"

For more information:
  https://www.shellcheck.net/wiki/SC2034 -- name appears unused. Verify use (...
  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
  https://www.shellcheck.net/wiki/SC2006 -- Use $(...) notation instead of le...