wyrics/gendl
2019-01-21 16:17:01 -06:00

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#!/bin/sh
##############################
# name: gendl
# lisc: gnu gplv3
# desc: download to stdout or
# file, independent of
# a specific downloader.
# ftp/wget/curl support.
# main: jadedctrl
##############################
# usage: gendl [-o output] url
#---------------------------------------
# backend bits
# NIL --> STRING
# return the download program you're using
function download_program
{
programs="ftp curl wget"
current=""
for program in $programs
do
if whereis $program > /dev/null
then
current=$program
fi
done
if uname -s | grep -e "LibertyBSD" -e "OpenBSD" > /dev/null
then
current="ftp"
fi
echo "$current"
}
# STRING PATH --> NIL
# download URL $1 to stdout
function download_stdout
{
program=$(download_program)
url=$1
case "$program" in
"ftp")
output="$(ftp -VMo- $url)"
;;
"curl")
output="$(curl $url)"
;;
"wget")
output="$(wget --quiet -O- $url)"
;;
esac
return_code=$?
echo "$output"
return $return_code
}
# STRING PATH --> NIL
# download URL $1 to path $2
function download_file
{
program=$(download_program)
url=$1
path=$2
case "$program" in
"ftp")
ftp -VMU "." -o $path $url
;;
"curl")
curl -o $path $url
;;
"wget")
wget --quiet -O $path $url
;;
esac
return_code=$?
if test $return_code -ne 0 2>/dev/null
then
rm $path 2> /dev/null
# for consistency in behavior; wget saves 404s anyway, whereas
# ftp doesn't save anything from 404s, etc.
fi
return $return_code
}
# --------------------------------------
# front-end string-manip
# STRING --> STRING
# return the last word in a string
function last_word
{
string="$1"
echo "$string" \
| rev \
| sed 's% .*%%' \
| rev
}
function usage
{
echo "usage: gendl [-o output] URL"
}
# --------------------------------------
# invocation
args="$(getopt o: $*)"
if test -z "$@" 2>/dev/null
then
usage
exit 2
fi
set -- $args
while test $# -ne 0
do
case "$1"
in
-o)
download_path="$2"; shift; shift;;
--)
shift; break;;
esac
done
url="$(last_word "$@")"
if test -n "$download_path" 2> /dev/null
then
download_file $url $download_path
else
download_stdout "$url"
fi