tools_eget

#!/bin/sh
# eget - simply shell on wget for loading directories over http (wget does not support wildcard for http)
# Use:
# eget http://ftp.altlinux.ru/pub/security/ssl/*
#
# Copyright (C) 2014-2014, 2016, 2020, 2022  Etersoft
# Copyright (C) 2014 Daniil Mikhailov <danil@etersoft.ru>
# Copyright (C) 2016-2017, 2020, 2022 Vitaly Lipatov <lav@etersoft.ru>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#

PROGDIR=$(dirname "$0")
PROGNAME=$(basename "$0")
CMDSHELL="/bin/sh"
[ "$PROGDIR" = "." ] && PROGDIR="$(pwd)"
if [ "$0" = "/dev/stdin" ] || [ "$0" = "sh" ] ; then
    PROGDIR=""
    PROGNAME=""
fi


fatal()
{
    echo "FATAL: $*" >&2
    exit 1
}

info()
{
    [ -n "$quiet" ] && return
    echo "$*" >&2
}

eget()
{
	if [ -n "$PROGNAME" ] ; then

		local bashopt=''
		#[ -n "$verbose" ] && bashopt='-x'

		(unset EGET_IPFS_GATEWAY; unset EGET_IPFS_API ; unset EGET_IPFS_DB ; $CMDSHELL $bashopt $PROGDIR/$PROGNAME "$@" )
	else
		#epm_main --inscript "$@"
		fatal "Improve me"
	fi
}

# TODO:
arch="$(uname -m)"

# copied from eepm project

# copied from /etc/init.d/outformat (ALT Linux)
isatty()
{
	# Set a sane TERM required for tput
	[ -n "$TERM" ] || TERM=dumb
	export TERM
	test -t 1
}

isatty2()
{
	# check stderr
	test -t 2
}


check_tty()
{
	isatty || return
	is_command tput >/dev/null 2>/dev/null || return
	# FreeBSD does not support tput -S
	echo | a= tput -S >/dev/null 2>/dev/null || return
	export USETTY="tput -S"
}

: ${BLACK:=0} ${RED:=1} ${GREEN:=2} ${YELLOW:=3} ${BLUE:=4} ${MAGENTA:=5} ${CYAN:=6} ${WHITE:=7}

set_boldcolor()
{
	[ -n "$USETTY" ] || return
	{
		echo bold
		echo setaf $1
	} | $USETTY
}

set_color()
{
	[ -n "$USETTY" ] || return
	{
		echo setaf $1
	} | $USETTY
}

restore_color()
{
	[ -n "$USETTY" ] || return
	{
		echo op; # set Original color Pair.
		echo sgr0; # turn off all special graphics mode (bold in our case).
	} | $USETTY
}


echover()
{
    [ -n "$verbose" ] || return
    echo "$*" >&2
}

# Print command line and run command line
showcmd()
{
	if [ -z "$quiet" ] ; then
		set_boldcolor $GREEN
		local PROMTSIG="\$"
		[ "$UID" = 0 ] && PROMTSIG="#"
		echo " $PROMTSIG $@"
		restore_color
	fi >&2
}

# Print command line and run command line
docmd()
{
	showcmd "$@"
	"$@"
}

verdocmd()
{
	[ -n "$verbose" ] && showcmd "$@"
	"$@"
}


# copied from epm
# print a path to the command if exists in $PATH
if a= which which 2>/dev/null >/dev/null ; then
    # the best case if we have which command (other ways needs checking)
    # TODO: don't use which at all, it is binary, not builtin shell command
print_command_path()
{
    a= which -- "$1" 2>/dev/null
}
elif a= type -a type 2>/dev/null >/dev/null ; then
print_command_path()
{
    a= type -fpP -- "$1" 2>/dev/null
}
else
print_command_path()
{
    a= type "$1" 2>/dev/null | sed -e 's|.* /|/|'
}
fi

# check if <arg> is a real command
is_command()
{
    print_command_path "$1" >/dev/null
}

# add realpath if missed
if ! is_command realpath ; then
realpath()
{
    [ -n "$*" ] || return
    readlink -f "$@"
}
fi


# check man glob
filter_glob()
{
	[ -z "$1" ] && cat && return
	# translate glob to regexp
	grep "$(echo "$1" | sed -e "s|\*|.*|g" -e "s|?|.|g")$"
}

filter_order()
{
    if [ -n "$SECONDLATEST" ] ; then
        sort -V | tail -n2 | head -n1
        return
    fi
    [ -z "$LATEST" ] && cat && return
    sort -V | tail -n1
}


is_fileurl()
{
    echo "$1" | grep -q "^/" && return
    echo "$1" | grep -q "^file:/"
}

path_from_url()
{
    echo "$1" | sed -e 's|^file://*|/|'
}

is_url()
{
    echo "$1" | grep -q "^[filehtps]*:/"
}

is_strange_url()
{
    local URL="$1"
    is_url "$URL" || return
    echo "$URL" | grep -q "[?&]"
}

is_ipfs_hash()
{
    # If a CID is 46 characters starting with "Qm", it's a CIDv0
    echo "$1" | grep -q -E "^Qm[[:alnum:]]{44}$" && return
    # TODO: CIDv1 support, see https://github.com/multiformats/cid
    return 1
}

is_ipfsurl()
{
    is_ipfs_hash "$1" && return
    echo "$1" | grep -q "^ipfs://"
}

is_httpurl()
{
    # TODO: improve
    echo "$1" | grep -q "^https://" & return
    echo "$1" | grep -q "^http://" & return
}

cid_from_url()
{
    echo "$1" | sed -e 's|^ipfs://*||' -e 's|\?.*||'
}


# args: cmd <URL> <options>
# will run cmd <options> <URL>
download_with_mirroring()
{
    local CMD="$1"
    shift
    local URL="$1"
    shift

    local res
    $CMD "$@" "$URL" && return
    res=$?
    [ -n "$CHECKMIRRORS" ] || return $res

    MIRROR="https://mirror.eterfund.ru"
    SECONDURL="$(echo "$URL" | sed -e "s|^.*://|$MIRROR/|")"
    $CMD "$@" "$SECONDURL" && URL="$SECONDURL" && return

    MIRROR="https://mirror.eterfund.org"
    SECONDURL="$(echo "$URL" | sed -e "s|^.*://|$MIRROR/|")"
    $CMD "$@" "$SECONDURL" && URL="$SECONDURL" && return
}



check_tty

quiet=''
verbose=''
WGETNOSSLCHECK=''
CURLNOSSLCHECK=''
WGETUSERAGENT=''
CURLUSERAGENT=''
WGETQ='' #-q
CURLQ='' #-s
# TODO: aria2c
# TODO: wget --trust-server-names
# TODO: 
WGETNAMEOPTIONS='--content-disposition'
CURLNAMEOPTIONS='--remote-name --remote-time --remote-header-name'

LISTONLY=''
CHECKURL=''
GETRESPONSE=''
GETFILENAME=''
GETREALURL=''
GETIPFSCID=''
LATEST=''
SECONDLATEST=''
CHECKMIRRORS=''
TARGETFILE=''
FORCEIPV=''


set_quiet()
{
    WGETQ='-q'
    CURLQ='-s'
    quiet=1
}


eget_help()
{
cat <<EOF

eget - wget like downloader wrapper with wildcard support in filename part of URL
Usage: eget [options] http://somesite.ru/dir/na*.log

Options:
    -q|--quiet                - quiet mode
    --verbose                 - verbose mode
    -k|--no-check-certificate - skip SSL certificate chain support
    -U|-A|--user-agent        - send browser like UserAgent
    -4|--ipv4|--inet4-only    - use only IPV4
    -6|--ipv6|--inet6-only    - use only IPV6
    -O-|-O -                  - output downloaded file to stdout
    -O file                   - download to this file
    --latest                  - print only latest version of a file
    --second-latest           - print only second to latest version of a file
    --allow-mirrors           - check mirrors if url is not accessible

    --list|--list-only        - print only URLs
    --check URL               - check if the URL is accessible (returns HTTP 200 OK)
    --get-response URL        - get response with all headers (ever if HEAD is not acceptable)
    --get-filename URL        - print filename for the URL (via Content-Disposition if applicable)
    --get-real-url URL        - print URL after all redirects

Supported URLs:
  ftp:// http:// https:// file:/ ipfs://

Supported backends (set like EGET_BACKEND=curl)
  wget curl (todo: aria2c)

Examples:
  $ eget http://ftp.somesite.ru/package-*.x64.tar
  $ eget http://ftp.somesite.ru/package *.tar
  $ eget https://github.com/owner/project package*.ext
  $ eget -O myname ipfs://QmVRUjnsnxHWkjq91KreCpUk4D9oZEbMwNQ3rzdjwND5dR
  $ eget --list http://ftp.somesite.ru/package-*.tar
  $ eget --check http://ftp.somesite.ru/test
  $ eget --list http://download.somesite.ru 'package-*.tar.xz'
  $ eget --list --latest https://github.com/telegramdesktop/tdesktop/releases 'tsetup.*.tar.xz'

EOF
}


if [ -z "$1" ] ; then
    echo "eget - wget like downloader wrapper with wildcard support, uses wget or curl as backend" >&2
    echo "Run $0 --help to get help" >&2
    exit 1
fi


while [ -n "$1" ] ; do

    case "$1" in
        -h|--help)
            eget_help
            exit
            ;;
        -q|--quiet)
            set_quiet
            ;;
        --verbose)
            verbose="$1"
            ;;
        -k|--no-check-certificate)
            WGETNOSSLCHECK='--no-check-certificate'
            CURLNOSSLCHECK='-k'
            ;;
        -U|-A|--user-agent)
            user_agent="Mozilla/5.0 (X11; Linux $arch) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36"
            WGETUSERAGENT="-U '$user_agent'"
            CURLUSERAGENT="-A '$user_agent'"
            ;;
        -4|--ipv4|--inet4-only)
            FORCEIPV="-4"
            ;;
        -6|--ipv6|--inet6-only)
            FORCEIPV="-6"
            ;;
        --list|--list-only)
            LISTONLY="$1"
            set_quiet
            ;;
        --check)
            CHECKURL="$1"
            #set_quiet
            ;;
        --get-filename)
            GETFILENAME="$1"
            ;;
        --get-response)
            GETRESPONSE="$1"
            ;;
        --get-real-url)
            GETREALURL="$1"
            ;;
        --get-ipfs-cid)
            GETIPFSCID="$1"
            ;;
        --latest)
            LATEST="$1"
            ;;
        --second-latest)
            SECONDLATEST="$1"
            ;;
        --check-mirrors)
            CHECKMIRRORS="$1"
            ;;
        -O)
            shift
            TARGETFILE="$1"
            ;;
        -O-)
            TARGETFILE="-"
            ;;
        *)
            break
            ;;
    esac
    shift
done


#############################3
# defaults

# https://github.com/ipfs/kubo/issues/5541
ipfs_diag_timeout='--timeout 10s'

ipfs_api_local="/ip4/127.0.0.1/tcp/5001"
[ -n "$EGET_IPFS_API" ] && ipfs_api_local="$EGET_IPFS_API"

ipfs_api_brave="/ip4/127.0.0.1/tcp/45005"

ipfs_gateway="https://cloudflare-ipfs.com/ipfs"
[ -n "$EGET_IPFS_GATEWAY" ] && ipfs_gateway="$EGET_IPFS_GATEWAY"
IPFS_GATEWAY="$ipfs_gateway"

# Test data: https://etersoft.ru/templates/etersoft/images/logo.png
ipfs_checkQm="QmYwf2GAMvHxfFiUFL2Mr6KUG6QrDiupqGc8ms785ktaYw"

get_ipfs_brave()
{
    local ipfs_brave="$(ls ~/.config/BraveSoftware/Brave-Browser/*/*/go-ipfs_* 2>/dev/null)"
    [ -n "$ipfs_brave" ] && [ -x "$ipfs_brave" ] || return
    echo "$ipfs_brave"
}

ipfs_access()
{
    [ -n "$IPFS_CMD" ] || fatal "IPFS is disabled"
    verdocmd $IPFS_CMD --api $IPFS_API $ipfs_diag_timeout diag sys >/dev/null
}

ipfs_check()
{
    [ -n "$IPFS_CMD" ] || fatal "IPFS is disabled"
    verdocmd $IPFS_CMD --api $IPFS_API $ipfs_diag_timeout cat "$1" >/dev/null
}



select_ipfs_mode()
{
    IPFS_CMD="$(get_ipfs_brave)"
    # if no EGET_IPFS_API, check brave
    if [ -z "$EGET_IPFS_API" ] && [ -n "$IPFS_CMD" ] ; then
        IPFS_API="$ipfs_api_brave"
        if ipfs_access ; then
            if ipfs_check "$ipfs_checkQm" ; then
                ipfs_mode="brave" && return
            else
                info "Skipped Brave: it is accessible via $IPFS_CMD --api $IPFS_API, but can't return shared $ipfs_checkQm"
            fi
        fi
    fi

    IPFS_CMD="$(print_command_path ipfs)"
    if [ -n "$IPFS_CMD" ] ; then
        IPFS_API="$ipfs_api_local"
        if ipfs_access ; then
            if ipfs_check "$ipfs_checkQm" ; then
                ipfs_mode="local" && return
            else
                info "Skipped local: it is accessible via $IPFS_CMD --api $IPFS_API, but can't return shared $ipfs_checkQm"
            fi
        fi
    fi

    # TODO: check checksum
    if docmd eget --check "$ipfs_gateway/$ipfs_checkQm" ; then
        ipfs_mode="gateway"
        return
    fi

    IPFS_GATEWAY=''
    if docmd eget --check "$(dirname $ipfs_gateway)" ; then
       info "IPFS gateway $ipfs_gateway is accessible, but can't return shared $ipfs_checkQm"
    else
       info "IPFS gateway $(dirname $ipfs_gateway) is not accessible"
    fi

    ipfs_mode="disabled"
}


# Functions for work with eget ipfs db
get_cid_by_url()
{
    local URL="$1"
    [ -r "$EGET_IPFS_DB" ] || return
    is_fileurl "$URL" && return 1
    grep -F "$URL Qm" "$EGET_IPFS_DB" | head -n1 | cut -f2 -d" "
}

put_cid_and_url()
{
    local URL="$1"
    local CID="$2"
    local FN="$3"
    [ -w "$EGET_IPFS_DB" ] || return

    is_fileurl "$URL" && return

    echo "$URL $CID $FN" >> "$EGET_IPFS_DB"
    echo "Placed in $EGET_IPFS_DB: $URL $CID $FN"
}

get_filename_by_cid()
{
    local CID="$1"
    [ -z "$EGET_IPFS_DB" ] && basename "$CID" && return
    grep -F " $CID " "$EGET_IPFS_DB" | head -n1 | cut -f3 -d" "
}

get_url_by_cid()
{
    local CID="$1"
    [ -z "$EGET_IPFS_DB" ] && echo "$CID" && return
    grep -F " $CID " "$EGET_IPFS_DB" | head -n1 | cut -f1 -d" "
}

###################


ipfs_mode="$EGET_IPFS"

# enable auto mode when set $EGET_IPFS_DB
[ -z "$ipfs_mode" ] && [ -n "$EGET_IPFS_DB" ] && ipfs_mode="auto"

if [ -n "$LISTONLY$CHECKURL" ] ; then
    ipfs_mode="disabled"
    EGET_IPFS_DB=''
fi


if [ "$ipfs_mode" != "disabled" ] && [ -n "$EGET_IPFS_DB" ] ; then
    ddb="$(dirname "$EGET_IPFS_DB")"
    if [ -d "$ddb" ] ; then
        info "Using eget IPFS db $EGET_IPFS_DB"
        [ -r "$EGET_IPFS_DB" ] || touch "$EGET_IPFS_DB"
    else
        EGET_IPFS_DB=''
    fi
fi


# detect if we run with ipfs:// or with auto
if is_ipfsurl "$1" && [ -z "$ipfs_mode" ] || [ "$ipfs_mode" = "auto" ] ; then
    info "Autodetecting for available IPFS relay..."
    select_ipfs_mode
    info "Auto selected IPFS mode: $ipfs_mode"
else
    [ -n "$ipfs_mode" ] && [ "$ipfs_mode" != "disabled" ] && info "IPFS mode: $ipfs_mode"
fi

IPFS_CMD=''

if [ "$ipfs_mode" = "disabled" ] ; then

ipfs_get()
{
    fatal "IPFS is disabled"
}

ipfs_put()
{
    fatal "IPFS is disabled"
}

ipfs_cat()
{
    fatal "IPFS is disabled"
}


elif [ "$ipfs_mode" = "brave" ] ; then
    IPFS_CMD="$(get_ipfs_brave)" || fatal "Can't find ipfs command in Brave"
    IPFS_PRETTY_CMD="~Brave-Browser/$(basename $IPFS_CMD)"
    IPFS_API="$ipfs_api_brave"
    ipfs_access || fatal "Can't access to Brave IPFS API (Brave browser is not running and IPFS is not activated?)"
    info "Will use $IPFS_PRETTY_CMD --api $IPFS_API"

elif [ "$ipfs_mode" = "local" ] ; then
    IPFS_CMD="$(print_command_path ipfs)" || fatal "Can't find ipfs command"
    IPFS_PRETTY_CMD="$IPFS_CMD"
    IPFS_API="$ipfs_api_local"
    ipfs_access || fatal "Can't access to IPFS API (ipfs daemon is not running?)"
    info "Will use $IPFS_PRETTY_CMD --api $IPFS_API"

elif [ "$ipfs_mode" = "gateway" ] ; then
    info "Will use eget $IPFS_GATEWAY/HASH"

ipfs_get_real_url()
{
    [ -n "$IPFS_GATEWAY" ] || fatal "ipfs http gateway is not set"
    echo "$IPFS_GATEWAY/$1"
}

ipfs_get()
{
    if [ -n "$2" ] ; then
        docmd eget -O "$2" "$(ipfs_get_real_url "$1")"
    else
        docmd eget "$(ipfs_get_real_url "$1")"
    fi
}

ipfs_cat()
{
    # FIXME:
    ipfs_get "$1" "-"
}

ipfs_put()
{
    fatal "IPFS add disabled if a gateway is used"
}
elif [ -z "$ipfs_mode" ] ; then
    :
else
    fatal "Unsupported eget ipfs mode $ipfs_mode"
fi

if [ -n "$IPFS_CMD" ] ; then

ipfs_get_real_url()
{
    return 1
}

ipfs_get()
{
    [ -n "$IPFS_CMD" ] || fatal "ipfs api is not usable"
    if [ -n "$2" ] ; then
        showcmd $IPFS_PRETTY_CMD --api $IPFS_API get -o "$2" "$1"
        $IPFS_CMD --api $IPFS_API get -o "$2" "$1"
    else
        showcmd $IPFS_PRETTY_CMD --api $IPFS_API get "$1"
        $IPFS_CMD --api $IPFS_API get "$1"
    fi
}

ipfs_put()
{
    [ -n "$IPFS_CMD" ] || fatal "ipfs api is not usable"

    # detect if -q is used (will output Qm instead of addded Qm)
    local qu="$1"
    [ "$qu" = "-q" ] || qu=''

    showcmd $IPFS_PRETTY_CMD --api $IPFS_API add "$@"

    local res
    res="$($IPFS_CMD --api $IPFS_API add "$@")" || return

    if [ -z "$qu" ] ; then
        res="$(echo "$res" | grep "^added Qm")" || return
        res="$(echo "$res" | cut -f2 -d" ")"
    fi

    is_ipfs_hash "$res" && echo "$res" && return
    fatal "Can't recognize $res IPFS hash"
}

ipfs_cat()
{
    [ -n "$IPFS_CMD" ] || fatal "ipfs api is not usable"
    showcmd $IPFS_PRETTY_CMD --api $IPFS_API cat "$1"
    $IPFS_CMD --api $IPFS_API cat "$1"
}

fi
###############################



WGET="$(print_command_path wget)"
CURL="$(print_command_path curl)"


if is_fileurl "$1" ; then
    EGET_BACKEND="file"
elif is_ipfsurl "$1" ; then
    EGET_BACKEND="ipfs"
fi


case "$EGET_BACKEND" in
    file|ipfs)
        ;;
    wget)
        [ -n "$WGET" ] || fatal "There are no wget in the system but you forced using it via EGET_BACKEND. Install it with $ epm install wget"
        ;;
    curl)
        [ -n "$CURL" ] || fatal "There are no curl in the system but you forced using it via EGET_BACKEND. Install it with $ epm install curl"
        ;;
    '')
        [ -n "$WGET" ] && EGET_BACKEND="wget"
        [ -z "$EGET_BACKEND" ] && [ -n "$CURL" ] && EGET_BACKEND="curl"
        [ -n "$EGET_BACKEND" ] || fatal "There are no wget nor curl in the system. Install something with $ epm install wget"
        ;;
    *)
        fatal "Uknown EGET_BACKEND $EGET_BACKEND"
        ;;
esac



if [ "$EGET_BACKEND" = "file" ] ; then

# put remote content to stdout
url_scat()
{
    local URL="$1"
    cat "$(path_from_url "$URL")"
}
# download to default name of to $2
url_sget()
{
    local URL="$1"
    if [ "$2" = "/dev/stdout" ] || [ "$2" = "-" ] ; then
       scat "$URL"
       return
    elif [ -n "$2" ] ; then
       cp -av "$(path_from_url "$URL")" "$2"
       return
    fi
    cp -av "$(path_from_url "$URL")" .
}

url_check()
{
    local URL="$1"
    test -f "$(path_from_url "$URL")"
}

url_get_filename()
{
    basename "$1"
}

url_get_real_url()
{
    echo "$1"
}

elif [ "$EGET_BACKEND" = "ipfs" ] ; then

# put remote content to stdout
url_scat()
{
    local URL="$1"
    ipfs_cat "$(cid_from_url "$URL")"
}
# download to default name of to $2
url_sget()
{
    local URL="$1"
    if [ "$2" = "/dev/stdout" ] || [ "$2" = "-" ] ; then
       scat "$URL"
       return
    elif [ -n "$2" ] ; then
       ipfs_get "$(cid_from_url "$URL")" "$2"
       return
    fi

    local fn="$(url_print_filename_from_url "$URL")"
    if [ -n "$fn" ] ; then
       ipfs_get "$(cid_from_url "$URL")" "$fn"
       return
    fi

    ipfs_get "$(cid_from_url "$URL")"
}

url_check()
{
    local URL="$1"
    # TODO: improve me
    scat "$URL" >/dev/null
}

url_print_filename_from_url()
{
    local URL="$1"
    local fn="$(echo "$URL" | sed -e 's|ipfs://.*\?filename=||')"
    [ "$URL" != "$fn" ] && echo "$fn" && return
}

url_get_filename()
{
    local URL="$1"
    url_print_filename_from_url "$URL" && return
    local CID="$(cid_from_url "$URL")"
    get_filename_by_cid "$CID"
}

url_get_real_url()
{
    local URL="$1"
    local CID="$(cid_from_url "$URL")"
    # if we use gateway, return URL with gateway
    ipfs_get_real_url "$URL" && return
    get_url_by_cid "$CID"
}


elif [ "$EGET_BACKEND" = "wget" ] ; then
__wget()
{
    if [ -n "$WGETUSERAGENT" ] ; then
        docmd $WGET $FORCEIPV $WGETQ $WGETNOSSLCHECK "$WGETUSERAGENT" "$@"
    else
        docmd $WGET $FORCEIPV $WGETQ $WGETNOSSLCHECK "$@"
    fi
}

# put remote content to stdout
url_scat()
{
    local URL="$1"
    download_with_mirroring __wget "$URL" -O-
}
# download to default name of to $2
url_sget()
{
    local URL="$1"
    if [ "$2" = "/dev/stdout" ] || [ "$2" = "-" ] ; then
       scat "$URL"
       return
    elif [ -n "$2" ] ; then
       download_with_mirroring __wget "$URL" -O "$2"
       return
    fi
# TODO: поддержка rsync для известных хостов?
# Не качать, если одинаковый размер и дата
# -nc
# TODO: overwrite always
    download_with_mirroring __wget "$URL" $WGETNAMEOPTIONS
}

url_get_response()
{
    local URL="$1"
    local answer
    answer="$(quiet=1 __wget --spider -S "$URL" 2>&1)"
    # HTTP/1.1 405 Method Not Allowed
    if echo "$answer" | grep -q "^ *HTTP/[12.]* 405" ; then
        (quiet=1 __wget --start-pos=5000G -S "$URL" 2>&1)
        return
    fi
    echo "$answer"
}


elif [ "$EGET_BACKEND" = "curl" ] ; then

__curl()
{
    if [ -n "$CURLUSERAGENT" ] ; then
        docmd $CURL $FORCEIPV --fail -L $CURLQ "$CURLUSERAGENT" $CURLNOSSLCHECK "$@"
    else
        docmd $CURL $FORCEIPV --fail -L $CURLQ $CURLNOSSLCHECK "$@"
    fi
}
# put remote content to stdout
url_scat()
{
    local URL="$1"
    download_with_mirroring __curl "$URL" --output -
}
# download to default name of to $2
url_sget()
{
    local URL="$1"
    local res
    if [ "$2" = "/dev/stdout" ] || [ "$2" = "-" ] ; then
       scat "$1"
       return
    elif [ -n "$2" ] ; then
       download_with_mirroring __curl "$URL" --output "$2"
       return
    fi

    download_with_mirroring __curl "$URL" $CURLNAMEOPTIONS
}

url_get_response()
{
    local URL="$1"
    local answer
    answer="$(quiet=1 __curl -LI "$URL" 2>&1)"
    # HTTP/1.1 405 Method Not Allowed
    if echo "$answer" | grep -q "^ *HTTP/[12.]* 405" ; then
        (quiet=1 __curl -L -i -r0-0 "$URL" 2>&1)
        return
    fi
    echo "$answer"
}


fi


# Common code for both wget and curl (http related)
if [ "$EGET_BACKEND" = "wget" ] || [ "$EGET_BACKEND" = "curl" ] ; then

url_get_headers()
{
    local URL="$1"
    url_get_response "$URL" | grep -i "^ *[[:alpha:]].*: " | sed -e 's|^ *||' -e 's|\r$||'
}

url_check()
{
    local URL="$1"
    url_get_response "$URL" | grep "HTTP/" | tail -n1 | grep -q -w "200\|404"
}

url_get_header()
{
    local URL="$1"
    local HEADER="$2"
    url_get_headers "$URL" | grep -i "^ *$HEADER: " | sed -e "s|^ *$HEADER: ||i"
}

url_get_real_url()
{
    local URL="$1"

    ! is_httpurl "$URL" && echo "$URL" && return

    # don't check location if we have made form of the URL
    [ -n "$MADEURL" ] && [ "$MADEURL" = "$URL" ] && echo "$URL" && return

    local loc
    for loc in $(url_get_header "$URL" "Location" | tac | sed -e 's| ||') ; do
        if ! is_strange_url "$loc" ; then
            echo "$loc"
            return
        fi
    done

    echo "$URL"
}

url_get_filename()
{
    local URL="$1"

    ! is_httpurl "$URL" && basename "$URL" && return

    # FIXME with wget
    local cd="$(url_get_header "$URL" "Content-Disposition")"
    if echo "$cd" | grep -q "filename=" ; then
        #Content-Disposition: attachment; filename=postman-linux-x64.tar.gz
        #content-disposition: attachment; filename="code-1.77.1-1680651749.el7.x86_64.rpm"
        echo "$cd" | sed -e 's|.*filename=||' -e 's|^"||' -e 's|";$||' -e 's|"$||'
        return
    fi

    basename "$(url_get_real_url "$URL")"
}

fi


if [ "$ipfs_mode" != "disabled" ] && [ -n "$EGET_IPFS_DB" ] &&  ! is_ipfsurl "$1"  ; then

download_to_ipfs()
{
    local URL="$1"
    local res
    #res="$(url_scat "$URL" | ipfs_put )" || return
    #res="$(echo "$res" | grep "^added Qm")" || return 1
    #CID="$(echo "$res" | cut -f2 -d" ")"
    # with -q to disable progress (mixed with download progress)
    res="$(url_scat "$URL" | ipfs_put -q)" || return
    is_ipfs_hash "$res" || return 1
    echo "$res"
}

# put remote content to stdout
scat()
{
    local URL="$1"
    url_scat "$URL"

    # It is list only function. Don't save to IPFS
    return

    ###################

    local CID="$(get_cid_by_url "$URL")"
    if [ -n "$CID" ] ; then
        info "$URL -> $CID"
        ipfs_cat "$CID"
        return
    fi

    CID="$(download_to_ipfs "$URL")" || return

    ipfs_cat "$CID" || return

    local FN="$(url_get_filename "$URL")" || return

    put_cid_and_url "$URL" "$CID" "$FN"
}

# download to default name of to $2
sget()
{
    local URL="$1"
    local TARGET="$2"

    if [ -n "$GETFILENAME" ] ; then
        get_filename "$URL"
        exit
    fi

    local REALURL="$(get_real_url "$URL")" || return

    if [ -n "$GETREALURL" ] ; then
        echo "$REALURL"
        exit
    fi

    # skip ipfs for cat
    if [ "$TARGET" = "/dev/stdout" ] || [ "$TARGET" = "-" ] ; then
       url_scat "$URL"
       return
    fi


    #if is_strange_url "$REALURL" ; then
    #    info "Just download strange URL $REALURL, skipping IPFS"
    #    url_sget "$REALURL" "$TARGET"
    #    return
    #fi

    local CID="$(get_cid_by_url "$REALURL")"
    if [ -n "$CID" ] ; then

        if [ -n "$GETIPFSCID" ] ; then
            echo "$CID"
            exit
        fi

        if [ -n "$GETFILENAME" ] ; then
            get_filename_by_cid "$CID"
            exit
        fi

        if [ -n "$GETREALURL" ] ; then
            get_url_by_cid "$CID"
            exit
        fi

        if [ -z "$TARGET" ] ; then
            # TODO: in some cases we can get name from URL...
            TARGET="$(get_filename_by_cid "$CID")"
            if [ -z "$TARGET" ] ; then
                TARGET="$CID"
            fi
        fi
        [ "$URL" = "$REALURL" ] && info "$URL -> $CID -> $TARGET" || info "$URL -> $REALURL -> $CID -> $TARGET"
        ipfs_get "$CID" "$TARGET" && return

        # fail get from IPFS, fallback
        url_sget "$REALURL" "$TARGET"
        return
    fi


    # download and put to IPFS
    local FN="$(url_get_filename "$REALURL")" || return
    if [ -z "$TARGET" ] ; then
        TARGET="$FN"
    fi

    if [ -n "$GETIPFSCID" ] ; then
         # add to IPFS and print out CID
         CID="$(ipfs_put --progress "$REALURL")" || return
         echo "$CID"
         exit
    fi

    # download file and add to IPFS
    url_sget "$REALURL" "$TARGET" || return
    CID="$(ipfs_put --progress "$TARGET")" || return

    put_cid_and_url "$REALURL" "$CID" "$FN"
}

check_url_is_accessible()
{
    local URL="$1"
    local REALURL="$(get_real_url "$URL")" || return
    local CID="$(get_cid_by_url "$REALURL")"
    if [ -n "$CID" ] ; then
        [ "$URL" = "$REALURL" ] && info "$URL -> $CID" || info "$URL -> $REALURL -> $CID"
        ipfs_check "$CID"
        return
    fi

    CID="$(download_to_ipfs "$REALURL")" || return

    local FN="$(url_get_filename "$REALURL")" || return
    ipfs_cat "$CID" >/dev/null || return
    put_cid_and_url "$REALURL" "$CID" "$FN"
}

get_filename()
{
    url_get_filename "$1"
}

get_real_url()
{
    url_get_real_url "$1"
}

else
scat()
{
    url_scat "$@"
}

sget()
{
    if [ -n "$GETFILENAME" ] ; then
        get_filename "$1"
        exit
    fi

    if [ -n "$GETREALURL" ] ; then
        get_real_url "$1"
        exit
    fi

    url_sget "$@"
}

check_url_is_accessible()
{
    url_check "$@"
}

get_filename()
{
    url_get_filename "$1"
}

get_real_url()
{
    url_get_real_url "$1"
}

fi


get_github_urls()
{
    # https://github.com/OWNER/PROJECT
    local owner="$(echo "$1" | sed -e "s|^https://github.com/||" -e "s|/.*||")" #"
    local project="$(echo "$1" | sed -e "s|^https://github.com/$owner/||" -e "s|/.*||")" #"
    [ -n "$owner" ] || fatal "Can't get owner from $1"
    [ -n "$project" ] || fatal "Can't get project from $1"
    local URL="https://api.github.com/repos/$owner/$project/releases"
    scat $URL | \
        grep -i -o -E '"browser_download_url": "https://.*"' | cut -d'"' -f4
}

# drop file path from URL
get_host_only()
{
    echo "$1/" | grep -Eo '(.*://[^/]+)'
}

concatenate_url_and_filename()
{
    local url="$1"
    local fn="$2"
    # workaround for a slash in the end of URL
    echo "$(echo "$url" | sed -e 's|/*$||' )/$fn"
}

# MADEURL filled with latest made URL as flag it is end form of URL
MADEURL=''

# Args: URL filename
make_fileurl()
{
    local url="$1"
    local fn="$2"

    fn="$(echo "$fn" | sed -e 's|^./||' -e 's|^/+||')"

    if is_fileurl "$url" ; then
        # if it is url
        :
    elif echo "$fn" | grep -q "^/" ; then
        # if there is file path from the root of the site
        url="$(get_host_only "$url")"
    elif echo "$url" | grep -q -v "/$" ; then
        # if there is no slash in the end of URL
        url="$(dirname "$url")"
    fi

    MADEURL="$(concatenate_url_and_filename "$url" "$fn")"
    echo "$MADEURL"
}

get_urls()
{
    if is_fileurl "$URL" ; then
        ls -1 "$(path_from_url "$URL")"
        return
    fi

    # cat html, divide to lines by tags and cut off hrefs only
    scat $URL | sed -e 's|<|<\n|g' -e 's|data-file=|href=|g' -e "s|'|\"|g" | \
         grep -i -o -E 'href="(.+)"' | cut -d'"' -f2
}


if [ -n "$CHECKURL" ] ; then
    #set_quiet
    URL="$1"
    check_url_is_accessible "$URL"
    res=$?
    if [ -n "$verbose" ] ; then
        [ "$res" = "0" ] && echo "$URL is accessible via network" || echo "$URL is NOT accessible via network"
    fi
    exit $res
fi

if [ -n "$GETRESPONSE" ] ; then
    url_get_response "$1"
    exit
fi


# separate part for github downloads
if echo "$1" | grep -q "^https://github.com/" && \
   echo "$1" | grep -q -v "/download/" && [ -n "$2" ] ; then
    MASK="$2"

    if [ -n "$LISTONLY" ] ; then
        get_github_urls "$1" | filter_glob "$MASK" | filter_order
        exit
    fi

    ERROR=0
    for fn in $(get_github_urls "$1" | filter_glob "$MASK" | filter_order) ; do
        MADEURL="$fn" # mark it is the end form of the URL
        sget "$fn" "$TARGETFILE" || ERROR=1
        [ -n "$TARGETFILE" ] && [ "$ERROR" = "0" ] && break
    done
    exit
fi

if is_ipfsurl "$1" ; then
    [ -n "$2" ] && fatal "too many args when ipfs://Qm... used: extra '$2' arg"
    sget "$1" "$TARGETFILE"
    exit
fi

# if mask is the second arg
if [ -n "$2" ] ; then
    URL="$1"
    MASK="$2"
else
    # do not support / at the end without separately specified mask
    if echo "$1" | grep -q "/$" ; then
        fatal "Use http://example.com/e/* to download all files in dir"
    fi

    # drop mask part
    URL="$(dirname "$1")/"
    # wildcards allowed only in the last part of path
    MASK=$(basename "$1")
fi

# https://www.freeoffice.com/download.php?filename=freeoffice-2021-1062.x86_64.rpm
if echo "$URL" | grep -q "[*]" ; then
    fatal "Error: there are globbing symbol (*) in $URL. It is allowed only for mask part"
fi

is_url "$MASK" && fatal "eget supports only one URL as argument"
[ -n "$3" ] && fatal "too many args: extra '$3'. May be you need use quotes for arg with wildcards."

# TODO: curl?
# If ftp protocol, just download
if echo "$URL" | grep -q "^ftp://" ; then
    [ -n "$LISTONLY" ] && fatal "TODO: list files for ftp:// is not supported yet"
    sget "$1" "$TARGETFILE"
    exit
fi


if [ -n "$LISTONLY" ] ; then
    for fn in $(get_urls | filter_glob "$MASK" | filter_order) ; do
        is_url "$fn" && echo "$fn" && continue
        make_fileurl "$URL" "$fn"
    done
    exit
fi

# If there is no wildcard symbol like asterisk, just download
if echo "$MASK" | grep -qv "[*?]" || echo "$MASK" | grep -q "[?].*="; then
    sget "$1" "$TARGETFILE"
    exit
fi

ERROR=0
for fn in $(get_urls | filter_glob "$MASK" | filter_order) ; do
    is_url "$fn" || fn="$(make_fileurl "$URL" "$fn" )" #"
    sget "$fn" "$TARGETFILE" || ERROR=1
    [ -n "$TARGETFILE" ] && [ "$ERROR" = "0" ] && break
done
exit $ERROR