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...