diff --git a/bin/ZZZ.sh b/bin/ZZZ.sh
index 9277d81..fe88ec6 100644
--- a/bin/ZZZ.sh
+++ b/bin/ZZZ.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# ZZZ
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
diff --git a/bin/browser.sh b/bin/browser.sh
index 3e35f35..3868188 100644
--- a/bin/browser.sh
+++ b/bin/browser.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# browser
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
diff --git a/bin/credentials.sh b/bin/credentials.sh
index 6e4f8d1..c28ef80 100644
--- a/bin/credentials.sh
+++ b/bin/credentials.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# credentials
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
@@ -12,10 +12,7 @@
 
 usage()
 {
-	cat - <<. >&2
-Usage:
-	${0##*/} [-2pu] service
-.
+	printf "Usage: %s [-2pu] service\n" "${0##*/}" >&2
 	exit 1
 }
 
diff --git a/bin/fetch.sh b/bin/fetch.sh
index 40e3cf8..5e26232 100644
--- a/bin/fetch.sh
+++ b/bin/fetch.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# fetch
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
@@ -9,9 +9,10 @@
 # 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()
 {
-	printf "Usage: %s [-T] URL [URLs...]\n" "${0##*/}">&2
+	printf "Usage: %s [-T] URL [URL ...]\n" "${0##*/}">&2
 	exit 1
 }
 
@@ -34,9 +35,7 @@ while getopts T flag; do
 	esac
 done
 shift $(($OPTIND - 1))
-if [ $# -eq 0 ]; then
-	usage
-fi
+[ $# -gt 0 ] || usage
 
 : ${ARCHIVE_BASEDIR:=~/tmp/archive}
 mkdir -p "$ARCHIVE_BASEDIR"
diff --git a/bin/imgresize.sh b/bin/imgresize.sh
index 98d47a6..245ac49 100644
--- a/bin/imgresize.sh
+++ b/bin/imgresize.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# imgresize
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
@@ -10,7 +10,8 @@
 # Dedication along with this software. If not, see
 # <http://creativecommons.org/publicdomain/zero/1.0/>.
 
-usage() {
+usage()
+{
 	cat - <<. >&2
 Usage:
 	${0##*/} size in-file out-file
@@ -20,24 +21,21 @@ Usage:
 	exit 1
 }
 
-check_dimension_format() {
+err()
+{
+	printf "%s: %s\n" "${0##*/}" "$*" >&2
+	exit 1
+}
+
+check_dimension_format()
+{
 	printf "%s\n" "$1" | grep -q "^[0-9]*x[0-9]*\$" \
 	    && [ "$1" != "x" ]
 }
 
-if [ $# -ne 3 ] || ! check_dimension_format "$1"; then
-	usage
-fi
-if [ -z "$2" ]; then
-	printf "%s: Input file name can't be empty.\n" \
-	    "${0##*/}" >&2
-	exit 1
-fi
-if [ -z "$3" ]; then
-	printf "%s: Output file name can't be empty.\n" \
-	    "${0##*/}" >&2
-	exit 1
-fi
+[ $# -eq 3 ] && check_dimension_format "$1" || usage
+[ -n "$2" ] || err "Input file name can't be empty."
+[ -n "$3" ] || err "Output file name can't be empty."
 
 size=$1
 w=${size%x*}
@@ -52,8 +50,7 @@ case $infile in
 	;;
 *.png)	inprog=pngtopam
 	;;
-*)	printf "%s: Unknown input format.\n" "${0##*/}" >&2
-	exit 1
+*)	err "Unknown input format."
 	;;
 esac
 
@@ -64,8 +61,7 @@ case $outfile in
 	;;
 *.png)	outprog=pamtopng
 	;;
-*)	printf "%s: Unknown output format.\n" "${0##*/}" >&2
-	exit 1
+*)	err "Unknown output format."
 	;;
 esac
 
diff --git a/bin/invidious.sh b/bin/invidious.sh
index 8d77d61..bd1ddba 100644
--- a/bin/invidious.sh
+++ b/bin/invidious.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# invidious
 # Written in 2019 by Leslie
 # Modified in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
@@ -11,20 +11,25 @@
 # Dedication along with this software. If not, see
 # <http://creativecommons.org/publicdomain/zero/1.0/>.
 
-usage() {
+usage()
+{
 	printf "Usage: %s url\n" "${0##*/}" >&2
 	exit 1
 }
 
-if [ $# -ne 1 ]; then
-	usage
-fi
+err()
+{
+	printf "%s: %s\n" "${0##*/}" "$*" >&2
+	exit 1
+}
+
+[ $# -eq 1 ] || usage
 
 case $1 in
 "https://invidio.us/watch?v="*)
 	;;
-*)	printf "%s: Not an invidio.us url.\n" "${0##*/}" >&2
-	exit 1
+*)	err "Not an invidio.us url."
+	;;
 esac
 
 video_id=
@@ -34,21 +39,17 @@ for param in $(printf "%s\n" "${1##*"?"}" | tr "&" "\n"); do
 
 	v=${param#*=}
 	if [ ${#v} -ne 11 ]; then
-		printf "%s: "%s": not a video id.\n" "${0##*/}" "$v" >&2
+		printf  "%s: \"%s\": not a video ID." "${0##*/}" "$v" >&2
 		continue
 	fi
 	video_id=$v
 	break
 done
 
-if [ -z "$video_id" ]; then
-	printf "%s: no video ID in URL.\n" "${0##*/}" >&2
-	exit 1
-fi
+[ -n "$video_id" ] || err "no video ID in URL."
 
-dl_option=$(ftp -o - "$1" 2>/dev/null \
-    | grep "<option value='{" \
-    | head -n 1 | cut -d "\"" -f 8)
+dl_option=$(ftp -o - "$1" 2>/dev/null | grep -F "<option value='{" |
+    head -n 1 | cut -d "\"" -f 8)
 
 printf "https://invidio.us/latest_version?id=%s&itag=%s\n" \
     "$video_id" "$dl_option"
diff --git a/bin/rfcopen.sh b/bin/rfcopen.sh
index bde1e93..e3bc310 100644
--- a/bin/rfcopen.sh
+++ b/bin/rfcopen.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# rfcopen
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
@@ -10,12 +10,20 @@
 # Dedication along with this software. If not, see
 # <http://creativecommons.org/publicdomain/zero/1.0/>.
 
-usage() {
+usage()
+{
 	printf "Usage: %s [-T] rfc-number\n" "${0##*/}" >&2
 	exit 1
 }
 
-tonumber() {
+err()
+{
+	printf "%s: %s\n" "${0##*/}" "$*" >&2
+	exit 1
+}
+
+tonumber()
+{
 	printf "%u" "$1" 2>/dev/null
 }
 
@@ -32,18 +40,13 @@ while getopts T flag; do
 done
 shift $(($OPTIND - 1))
 
-if [ $# -ne 1 ] || [ -z "$1" ] || ! n=$(tonumber "$1"); then
-	usage
-fi
+[ $# -eq 1 ] && [ -n "$1" ] && n=$(tonumber "$1") || usage
 rfcfile=$RFCDIR/rfc$n.txt
 url=https://tools.ietf.org/rfc/rfc$n.txt
 
 mkdir -p "$RFCDIR"
 if [ ! -f "$rfcfile" ]; then
-	if ! $torsocks ftp -Vo "$rfcfile" "$url"; then
-		printf "%s: Couldn't fetch RFC %u\n" "${0##*/}" "$n" >&2
-		exit 1
-	fi
+	$torsocks ftp -Vo "$rfcfile" "$url" || err "Couldn't fetch RFC $n."
 fi
 
 ${PAGER:-more} "$rfcfile"
diff --git a/bin/screenshot.sh b/bin/screenshot.sh
index 5a601b9..b3764ab 100644
--- a/bin/screenshot.sh
+++ b/bin/screenshot.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# screenshot
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
@@ -10,7 +10,8 @@
 # Dedication along with this software. If not, see
 # <http://creativecommons.org/publicdomain/zero/1.0/>.
 
-usage() {
+usage()
+{
 	cat - <<. >&2
 Usage:
 	${0##*/}
@@ -21,30 +22,25 @@ Usage:
 	exit 1
 }
 
-save_screenshot() {
+err()
+{
+	printf "%s: %s\n" "${0##*/}" "$*" >&2
+	exit 1
+}
+
+save_screenshot()
+{
 	xwdtopnm | pnmtopng >~/media/ss/"$(date +%Y%m%d-%H%M%S)".png
 }
 
 case $# in
 0)	xwd -silent -root | save_screenshot
 	;;
-1)	if [ "$1" != "-window" ]; then
-		printf "%s: Unknown option \"%s\".\n" \
-		    "${0##*/}" "$1" >&2
-		exit 1
-	fi
+1)	[ "$1" = "-window" ] || err "Unknown option \"$1\"."
 	xwd -silent | save_screenshot
 	;;
-2)	if [ "$1" != "-id" ] && [ "$1" != "-name" ]; then
-		printf "%s: Unknown option \"%s\".\n" \
-		    "${0##*/}" "$1" >&2
-		exit 1
-	fi
-	if [ -z "$2" ]; then
-		printf "%s: %s expects a non-empty parameter.\n" \
-		    "${0##*/}" "$1" >&2
-		exit 1
-	fi
+2)	[ "$1" = "-id" ] || [ "$1" = "-name" ] || err "Unknown option \"$1\"."
+	[ -n "$2" ] || err "$1 expects a non-empty parameter."
 	xwd -silent "$1" "$2" | save_screenshot
 	;;
 *)	usage
diff --git a/bin/tor-browser.sh b/bin/tor-browser.sh
index 6b46d46..9de04eb 100644
--- a/bin/tor-browser.sh
+++ b/bin/tor-browser.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# tor-browser
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
diff --git a/bin/w3m-copy-link.sh b/bin/w3m-copy-link.sh
index 0a57a91..7421185 100644
--- a/bin/w3m-copy-link.sh
+++ b/bin/w3m-copy-link.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# w3m-copy-link
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
diff --git a/bin/xsekrit.sh b/bin/xsekrit.sh
index 9d4e140..183d62d 100644
--- a/bin/xsekrit.sh
+++ b/bin/xsekrit.sh
@@ -1,5 +1,5 @@
 #!/bin/sh
-# env
+# xsekrit
 # Written in 2019 by Lucas
 # CC0 1.0 Universal/Public domain - No rights reserved
 #
@@ -10,12 +10,18 @@
 # Dedication along with this software. If not, see
 # <http://creativecommons.org/publicdomain/zero/1.0/>.
 
-if [ $# -ne 1 ] || [ -z "$1" ]; then
+usage()
+{
 	printf "Usage: %s key\n" "${0##*/}" >&2
 	exit 1
-fi
-if ! sekrit has "$1"; then
-	printf "%s: Unknown key \"%s\".\n" "${0##*/}" "$1" >&2
+}
+
+err()
+{
+	printf "%s: %s\n" "${0##*/}" "$*" >&2
 	exit 1
-fi
+}
+
+[ $# -eq 1 ] && [ -n "$1" ] || usage
+sekrit has "$1" || err "Unknown key \"$1\"."
 sekrit get "$1" | xclip -q -r -l 1 -sel clip 2>/dev/null