test a url for gzip encoding

README.md

test gzip encoding of url

This is a simple PASS / FAIL test indicating if a url is providing gzip encoded content.

test-gzip-encoding

#!/bin/bash
Usage() {
    cat <<EOF
Usage: ${0##*/} url

  Indicate whether or not a url seems to support gzip encoding.

  options:
    -v | --verbose: show debug info.
EOF
}

[ "$1" = "--help" -o "$1" = "-h" ] && { Usage; exit 0; }
[ "$1" = "-v" -o "$1" = "--verbose" ] && verbose=true && shift ||
    verbose=false

TEMP_D="$(mktemp -d)"
cleanup() { rm -Rf "${TEMP_D}"; }
trap cleanup EXIT 

url="$1"
set -e

cd "$TEMP_D"
cmd=( curl -v 
   --header "Accept-Encoding: gzip"
   --dump-header headers-received
   --output content
   "$url" 
)
! $verbose || echo "${cmd[@]}" 1>&2
"${cmd[@]}" 2> stderr
sed -n 's/^> //p' stderr > headers-sent
mime=$(file --brief --mime content)
mime=${mime%%;*}
size=$(stat "--format=%s" content)
sed -i 's/\r//' headers-received
encoding=$(awk '$1 == "Content-Encoding:" { print $2 }' headers-received)

if [ "$encoding" = "gzip" -a "$mime" = "application/gzip" ]; then
    echo "PASS: encoding='${encoding}' mime='${mime}' size=$size"
    RET=0
else
    echo "FAIL: encoding='${encoding}' mime='${mime}' size=$size"
    RET=1
fi

$verbose || exit $RET

echo == headers-sent ==
cat headers-sent
echo == headers-received ==
cat headers-received

exit $RET