fetch: Don't mess stdout with progress bar

Instead of using default ftp(1), if stdin is a tty, redirect ftp(1)
stdout to the tty. This implies know you can safely do

	$ fetch ... | sxiv

bin/fetch.sh

@@ -9,12 +9,21 @@
 # warranty. You should have received a copy of the CC0 Public Domain
 # Dedication along with this software. If not, see
 # <http://creativecommons.org/publicdomain/zero/1.0/>.
-
-usage() {
+usage()
+{
 	printf "Usage: %s [-T] URL [URLs...]\n" "${0##*/}">&2
 	exit 1
 }
 
+fetch_cmd()
+{
+	if [ -t 0 ]; then
+		$torsocks ftp "$@" >$(tty)
+	else
+		$torsocks ftp "$@"
+	fi
+}
+
 torsocks=torsocks
 while getopts T flag; do
 	case $flag in
@@ -52,7 +61,7 @@ for url; do
 	mkdir -p "$outdir"
 
 	{
-		$torsocks ftp -o "$outdir/file" "$url" \
+		fetch_cmd -o "$outdir/file" "$url" \
 		    && printf "%s\n" "$url" >"$outdir/url" \
 		    && printf "%s\n" "$name" >"$outdir/name" \
 		    && printf "%s\n" "$url" >>"$everything" \