shellcheck fixes

36 files changed, 187 insertions, 170 deletions

diff --git a/misc/auto-completion/bash/nnn-completion.bash b/misc/auto-completion/bash/nnn-completion.bash
index 22180e5..638df49 100644
--- a/misc/auto-completion/bash/nnn-completion.bash
+++ b/misc/auto-completion/bash/nnn-completion.bash
@@ -5,7 +5,8 @@
 #   Arun Prakash Jana <engineerarun@gmail.com>
 #
 
-_nnn () {
+_nnn ()
+{
     COMPREPLY=()
     local IFS=$' \n'
     local cur=$2 prev=$3
@@ -36,7 +37,7 @@ _nnn () {
         COMPREPLY=( $(compgen -f -d -- "$cur") )
     elif [[ $prev == -e ]]; then
         local sessions_dir=${XDG_CONFIG_HOME:-$HOME/.config}/nnn/sessions
-        COMPREPLY=( $(compgen -W "$(ls $sessions_dir)" -- "$cur") )
+        COMPREPLY=( $(compgen -W "$(ls "$sessions_dir")" -- "$cur") )
     elif [[ $cur == -* ]]; then
         COMPREPLY=( $(compgen -W "${opts[*]}" -- "$cur") )
     else
diff --git a/misc/quitcd/quitcd.bash b/misc/quitcd/quitcd.bash
index 70498cb..5c94b11 100644
--- a/misc/quitcd/quitcd.bash
+++ b/misc/quitcd/quitcd.bash
@@ -1,24 +1,24 @@
-n()
+n ()
 {
     # Block nesting of nnn in subshells
-    if [ $(expr $NNNLVL + 0) -ge 1 ]; then
+    if [ "$((NNNLVL + 0))" -ge 1 ]; then
         echo "nnn is already running"
         return
     fi
 
+    # The default behaviour is to cd on quit (nnn checks if NNN_TMPFILE is set)
+    # To cd on quit only on ^G, export NNN_TMPFILE after the call to nnn
+    export NNN_TMPFILE=${XDG_CONFIG_HOME:-$HOME/.config}/nnn/.lastd
+
     # Unmask ^Q (, ^V etc.) (if required, see `stty -a`) to Quit nnn
     # stty start undef
     # stty stop undef
     # stty lwrap undef
 
-    # The default behaviour is to cd on quit (nnn checks if NNN_TMPFILE is set)
-    # To cd on quit only on ^G, export NNN_TMPFILE after the call to nnn
-    export NNN_TMPFILE=${XDG_CONFIG_HOME:-$HOME/.config}/nnn/.lastd
-
     nnn "$@"
 
-    if [ -f $NNN_TMPFILE ]; then
-            . $NNN_TMPFILE
-            rm -f $NNN_TMPFILE > /dev/null
+    if [ -f "$NNN_TMPFILE" ]; then
+            . "$NNN_TMPFILE"
+            rm -f "$NNN_TMPFILE" > /dev/null
     fi
 }
diff --git a/misc/quitcd/quitcd.zsh b/misc/quitcd/quitcd.zsh
index 57f0fcf..5c94b11 100644
--- a/misc/quitcd/quitcd.zsh
+++ b/misc/quitcd/quitcd.zsh
@@ -1,7 +1,7 @@
-n()
+n ()
 {
     # Block nesting of nnn in subshells
-    if [ $(expr $NNNLVL + 0) -ge 1 ]; then
+    if [ "$((NNNLVL + 0))" -ge 1 ]; then
         echo "nnn is already running"
         return
     fi
@@ -17,8 +17,8 @@ n()
 
     nnn "$@"
 
-    if [ -f $NNN_TMPFILE ]; then
-            . $NNN_TMPFILE
-            rm $NNN_TMPFILE
+    if [ -f "$NNN_TMPFILE" ]; then
+            . "$NNN_TMPFILE"
+            rm -f "$NNN_TMPFILE" > /dev/null
     fi
 }
diff --git a/misc/test/mktest.sh b/misc/test/mktest.sh
index 2d1decf..aa5a921 100755
--- a/misc/test/mktest.sh
+++ b/misc/test/mktest.sh
@@ -7,7 +7,7 @@ test -e outdir && {
     exit 1
 }
 
-mkdir -p outdir && cd outdir
+mkdir -p outdir && cd outdir || exit 1
 
 echo 'It works!' > normal.txt
 echo 'Με δουλέβει;' > 'κοινό.txt'
diff --git a/plugins/.nnn-plugin-helper b/plugins/.nnn-plugin-helper
index ec66a29..c26566d 100644
--- a/plugins/.nnn-plugin-helper
+++ b/plugins/.nnn-plugin-helper
@@ -6,6 +6,7 @@
 # Author: Anna Arad
 
 selection=${XDG_CONFIG_HOME:-$HOME/.config}/nnn/.selection
+export selection
 
 ## Ask nnn to switch to directory $1 in context $2.
 ## If $2 is not provided, the function asks explicitly.
@@ -20,11 +21,11 @@ nnn_cd () {
     if [ -n "$2" ]; then
         context=$2
     else
-        echo -n "Choose context 1-4 (blank for current): "
-        read context
+        printf "Choose context 1-4 (blank for current): "
+        read -r context
     fi
 
-    echo -n ${context:-0}$dir > $NNN_PIPE
+    printf "%s" "${context:-0}$dir" > "$NNN_PIPE"
 }
 
 cmd_exists () {
diff --git a/plugins/boom b/plugins/boom
index 47036e0..40931b4 100755
--- a/plugins/boom
+++ b/plugins/boom
@@ -15,7 +15,7 @@ if [ ! -z "$GUIPLAYER" ]; then
     find . -type f \( -iname "*.mp3" -o -iname "*.flac" -o -iname "*.webm" -o -iname "*.wma" \) | sort -R | head -n $NUMTRACKS | xargs -d "\n" "$PLAYER" > /dev/null 2>&1 &
 
     # detach the player
-    disown
+    sleep 1
 else
     # start MOC server
     mocp -S
diff --git a/plugins/checksum b/plugins/checksum
index 2040e68..0c13da2 100755
--- a/plugins/checksum
+++ b/plugins/checksum
@@ -21,8 +21,8 @@ chsum=md5
 checksum_type()
 {
     echo "possible checksums: md5, sha1, sha224, sha256, sha384, sha512"
-    echo -n "create md5 (m), sha256 (s), sha512 (S) (or type one of the above checksums) [default=m]: "
-    read chsum_resp
+    printf "create md5 (m), sha256 (s), sha512 (S) (or type one of the above checksums) [default=m]: "
+    read -r chsum_resp
     for chks in md5 sha1 sha224 sha256 sha384 sha512
     do
         if [ "$chsum_resp" = "$chks" ]; then
@@ -38,8 +38,8 @@ checksum_type()
 }
 
 if [ -s "$selection" ]; then
-    echo -n "work with selection (s) or current file (f) [default=f]: "
-    read resp
+    printf "work with selection (s) or current file (f) [default=f]: "
+    read -r resp
 fi
 
 if [ "$resp" = "s" ]; then
@@ -49,10 +49,10 @@ elif [ -n "$1" ]; then
     if [ -f "$1" ]; then
         for chks in md5 sha1 sha224 sha256 sha384 sha512
         do
-            if [ "$(echo "$1" | grep \.${chks}$)" ]; then
+            if echo "$1" | grep -q \.${chks}$; then
                 ${chks}sum -c < "$1"
-                read dummy
-                exit
+                read -r _
+                return
             fi
         done
         checksum_type
diff --git a/plugins/dragdrop b/plugins/dragdrop
index 47b325c..ee4fc20 100755
--- a/plugins/dragdrop
+++ b/plugins/dragdrop
@@ -16,21 +16,22 @@
 selection=${XDG_CONFIG_HOME:-$HOME/.config}/nnn/.selection
 resp=f
 all=
-if which dragon-drag-and-drop 2>&1 >/dev/null; then
+if which dragon-drag-and-drop >/dev/null 2>&1; then
     dnd="dragon-drag-and-drop"
 else
     dnd="dragon"
 fi
 
-function add_file() {
-	echo -n "$@" >> "$selection"
-	echo -ne "\0" >> "$selection"
+add_file ()
+{
+	printf "%s" "$@" >> "$selection"
+	printf "\0" >> "$selection"
 }
 
-function use_all()
+use_all ()
 {
-    echo -n "mark --all (a) [default=none]: "
-    read resp
+    printf "mark --all (a) [default=none]: "
+    read -r resp
     if [ "$resp" = "a" ]; then
         all="--all"
     else
@@ -39,11 +40,11 @@ function use_all()
 }
 
 if [ -s "$selection" ]; then
-    echo -n "Drop file (r). Drag selection (s), Drag current directory (d) or drag current file (f) [default=f]: "
-    read resp
+    printf "Drop file (r). Drag selection (s), Drag current directory (d) or drag current file (f) [default=f]: "
+    read -r resp
 else
-    echo -n "Drop file (r). Drag current directory (d) or drag current file (f) [default=f]: "
-    read resp
+    printf "Drop file (r). Drag current directory (d) or drag current file (f) [default=f]: "
+    read -r resp
     if [ "$resp" = "s" ]; then
         resp=f
     fi
@@ -56,10 +57,10 @@ elif [ "$resp" = "d" ]; then
     use_all
     "$dnd" "$all" "$PWD/"* &
 elif [ "$resp" = "r" ]; then
-    echo -n > "$selection"
-    "$dnd" --print-path --target | while read f
+    printf > "$selection"
+    "$dnd" --print-path --target | while read -r f
     do
-            if echo -n "$f" | grep '^\(https\?\|ftps\?\|s\?ftp\):\/\/' ; then
+            if printf "%s" "$f" | grep '^\(https\?\|ftps\?\|s\?ftp\):\/\/' ; then
                     curl -LJO "$f"
                     add_file "$PWD/$(basename "$f")"
             elif [ -e "$f" ]; then
diff --git a/plugins/dups b/plugins/dups
index 0643025..2c5bb5e 100755
--- a/plugins/dups
+++ b/plugins/dups
@@ -9,7 +9,7 @@
 # Shell: POSIX compliant
 # Author: syssyphus
 
-find -size +0 -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate
+find . -size +0 -type f -printf "%s\n" | sort -rn | uniq -d | xargs -I{} -n1 find -type f -size {}c -print0 | xargs -0 md5sum | sort | uniq -w32 --all-repeated=separate
 
-echo "Press any key to exit"
-read dummy
+printf "Press any key to exit"
+read -r _
diff --git a/plugins/fzcd b/plugins/fzcd
index c4694e3..3633e64 100755
--- a/plugins/fzcd
+++ b/plugins/fzcd
@@ -5,7 +5,7 @@
 # Shell: POSIX compliant
 # Author: Anna Arad
 
-. $(dirname $0)/.nnn-plugin-helper
+. "$(dirname "$0")"/.nnn-plugin-helper
 
 if [ "$(cmd_exists fzy)" -eq "0" ]; then
 	if [ "$(cmd_exists fd)" -eq "0" ]; then
@@ -23,7 +23,7 @@ else
 	exit 1
 fi
 
-if [ "$?" -eq "0" ]; then
+if ! [ -z "$sel" ]; then
 	case "$(file -bi "$sel")" in
 		*directory*) ;;
 		*) sel=$(dirname "$sel") ;;
diff --git a/plugins/fzhist b/plugins/fzhist
index ca1db63..c47efa2 100755
--- a/plugins/fzhist
+++ b/plugins/fzhist
@@ -18,15 +18,15 @@ fi
 
 if ! [ -z "$entry" ]; then
     tmpfile=$(mktemp)
-    echo "$entry" >> $tmpfile
-    $EDITOR $tmpfile
+    echo "$entry" >> "$tmpfile"
+    $EDITOR "$tmpfile"
 
-    if [ -s $tmpfile ]; then
-        $SHELL -c "$(cat $tmpfile)"
+    if [ -s "$tmpfile" ]; then
+        $SHELL -c "$(cat "$tmpfile")"
     fi
 
-    rm $tmpfile
+    rm "$tmpfile"
 
-    echo -n "Press any key to exit"
-    read input
+    printf "Press any key to exit"
+    read -r _
 fi
diff --git a/plugins/fzopen b/plugins/fzopen
index 97da456..046e7e9 100755
--- a/plugins/fzopen
+++ b/plugins/fzopen
@@ -7,7 +7,7 @@
 # Shell: POSIX compliant
 # Author: Arun Prakash Jana
 
-entry="$(find -type f 2>/dev/null | fzy)"
+entry="$(find . -type f 2>/dev/null | fzy)"
 
 case "$(file -biL "$entry")" in
     *text*)
diff --git a/plugins/getplugs b/plugins/getplugs
index 34f599f..f7720a8 100755
--- a/plugins/getplugs
+++ b/plugins/getplugs
@@ -14,13 +14,13 @@ is_cmd_exists () {
 }
 
 merge () {
-	vimdiff $1 $2
+	vimdiff "$1" "$2"
 }
 
 prompt () {
-	echo "Plugin $1 already exists and is different."
-	echo -n "Keep (k), merge (m), overwrite (o) [default: k]? "
-	read operation
+	printf "%s" "Plugin $1 already exists and is different.\n"
+	printf "Keep (k), merge (m), overwrite (o) [default: k]? "
+	read -r operation
 
 	if [ "$operation" = "m" ]; then
 		op="merge"
@@ -40,27 +40,27 @@ else
 fi
 
 # backup any earlier plugins
-if [ -d $PLUGIN_DIR ]; then
-    tar -C $CONFIG_DIR -czf $CONFIG_DIR"plugins-$(date '+%Y%m%d%H%M').tar.gz" plugins/
+if [ -d "$PLUGIN_DIR" ]; then
+    tar -C "$CONFIG_DIR" -czf "$CONFIG_DIR""plugins-$(date '+%Y%m%d%H%M').tar.gz" plugins/
 fi
 
-mkdir -p $PLUGIN_DIR
-cd $CONFIG_DIR
+mkdir -p "$PLUGIN_DIR"
+cd "$CONFIG_DIR" || exit 1
 curl -Ls -O https://github.com/jarun/nnn/archive/master.tar.gz
 tar -zxf master.tar.gz
 
-cd nnn-master/plugins
+cd nnn-master/plugins || exit 1
 for f in *; do
-	if [ -f ../../plugins/$f ]; then
-		if [ "$(diff --brief $f ../../plugins/$f)" ]; then
-			prompt $f
-			$op $f ../../plugins/
+	if [ -f ../../plugins/"$f" ]; then
+		if [ "$(diff --brief "$f" ../../plugins/"$f")" ]; then
+			prompt "$f"
+			$op "$f" ../../plugins/
 		fi
 	else
-		cp -vRf $f ../../plugins/
+		cp -vRf "$f" ../../plugins/
 	fi
 done
-cd ../..
+cd ../.. || exit 1
 
 $sucmd mv -vf nnn-master/misc/nlaunch/nlaunch /usr/local/bin/
-rm -rf nnn-master/ master.tar.gz $PLUGIN_DIR/README.md
+rm -rf nnn-master/ master.tar.gz "$PLUGIN_DIR"/README.md
diff --git a/plugins/gutenread b/plugins/gutenread
index c1ff6ba..95634ab 100755
--- a/plugins/gutenread
+++ b/plugins/gutenread
@@ -25,25 +25,25 @@ BROWSER=w3m
 READER=
 
 if [ ! -z "$EBOOK_ID" ]; then
-    if [ ! -e $DIR ]; then
-        mkdir -p $DIR
-        cd $DIR
+    if [ ! -e "$DIR" ]; then
+        mkdir -p "$DIR"
+        cd "$DIR" || exit 1
 
         if [ -z "$READER" ]; then
-            curl -L -O "https://www.gutenberg.org/files/"$EBOOK_ID"/"$EBOOK_ID"-h.zip"
+            curl -L -O https://www.gutenberg.org/files/"$EBOOK_ID"/"$EBOOK_ID"-h.zip
             unzip "$EBOOK_ID"-h.zip
         else
-            curl -L -o "$EBOOK_ID".epub "http://www.gutenberg.org/ebooks/"$EBOOK_ID".epub.noimages"
+            curl -L -o "$EBOOK_ID".epub http://www.gutenberg.org/ebooks/"$EBOOK_ID".epub.noimages
         fi
     fi
 
-    if [ -d $DIR ]; then
+    if [ -d "$DIR" ]; then
         if [ -z "$READER" ]; then
-            "$BROWSER" $DIR/"$EBOOK_ID"-h/"$EBOOK_ID"-h.htm
+            "$BROWSER" "$DIR"/"$EBOOK_ID"-h/"$EBOOK_ID"-h.htm
         else
-            "$READER" $DIR/"$EBOOK_ID".epub
+            "$READER" "$DIR"/"$EBOOK_ID".epub
         fi
     fi
 else
-    "$BROWSER" $BROWSE_LINK
+    "$BROWSER" "$BROWSE_LINK"
 fi
diff --git a/plugins/imgresize b/plugins/imgresize
index 01917e7..def5560 100755
--- a/plugins/imgresize
+++ b/plugins/imgresize
@@ -21,8 +21,8 @@ res=
 minsize=1048576
 
 if [ -z "$res" ]; then
-    echo -n "desktop resolution (hxv): "
-    read res
+    printf "desktop resolution (hxv): "
+    read -r res
 fi
 
 if ! [ -z "$res" ] && ! [ -z "$minsize" ]; then
diff --git a/plugins/imgur b/plugins/imgur
index 8b39b55..a571515 100755
--- a/plugins/imgur
+++ b/plugins/imgur
@@ -78,14 +78,22 @@ upload_timeout="120"
 upload_retries="1"
 
 if is_mac; then
+  # shellcheck disable=SC2034
   screenshot_select_command="screencapture -i %img"
+  # shellcheck disable=SC2034
   screenshot_window_command="screencapture -iWa %img"
+  # shellcheck disable=SC2034
   screenshot_full_command="screencapture %img"
+  # shellcheck disable=SC2034
   open_command="open %url"
 else
+  # shellcheck disable=SC2034
   screenshot_select_command="scrot -s %img"
+  # shellcheck disable=SC2034
   screenshot_window_command="scrot %img"
+  # shellcheck disable=SC2034
   screenshot_full_command="scrot %img"
+  # shellcheck disable=SC2034
   open_command="xdg-open %url"
 fi
 open="true"
@@ -162,7 +170,7 @@ function take_screenshot() {
   cmd=${!cmd//\%img/${1}}
 
   shot_err="$(${cmd} &>/dev/null)" #takes a screenshot with selection
-  if [ "${?}" != "0" ]; then
+  if ! [ -z "$shot_err" ]; then
     echo "Failed to take screenshot '${1}': '${shot_err}'. For more information visit https://github.com/jomo/imgur-screenshot/wiki/Troubleshooting" | tee -a "${log_file}"
     notify error "Something went wrong :(" "Information has been logged"
     exit 1
@@ -171,8 +179,8 @@ function take_screenshot() {
 
 function check_for_update() {
   # exit non-zero on HTTP error, output only the body (no stats) but output errors, follow redirects, output everything to stdout
-  remote_version="$(curl --compressed -fsSL --stderr - "https://api.github.com/repos/jomo/imgur-screenshot/releases" | egrep -m 1 --color 'tag_name":\s*".*"' | cut -d '"' -f 4)"
-  if [ "${?}" -eq "0" ]; then
+  remote_version="$(curl --compressed -fsSL --stderr - "https://api.github.com/repos/jomo/imgur-screenshot/releases" | grep -Em 1 --color 'tag_name":\s*".*"' | cut -d '"' -f 4)"
+  if ! [ -z "$remote_version" ]; then
     if [ ! "${current_version}" = "${remote_version}" ] && [ ! -z "${current_version}" ] && [ ! -z "${remote_version}" ]; then
       echo "Update found!"
       echo "Version ${remote_version} is available (You have ${current_version})"
@@ -249,7 +257,7 @@ function refresh_access_token() {
   token_url="https://api.imgur.com/oauth2/token"
   # exchange the refresh token for access_token and refresh_token
   response="$(curl --compressed -fsSL --stderr - -F "client_id=${imgur_acct_key}" -F "client_secret=${imgur_secret}" -F "grant_type=refresh_token" -F "refresh_token=${refresh_token}" "${token_url}")"
-  if [ ! "${?}" -eq "0" ]; then
+  if ! [ -z "$response" ]; then
     # curl failed
     handle_upload_error "${response}" "${token_url}"
     exit 1
@@ -265,9 +273,9 @@ function save_access_token() {
     exit 1
   fi
 
-  access_token="$(egrep -o 'access_token":".*"' <<<"${1}" | cut -d '"' -f 3)"
-  refresh_token="$(egrep -o 'refresh_token":".*"' <<<"${1}" | cut -d '"' -f 3)"
-  expires_in="$(egrep -o 'expires_in":[0-9]*' <<<"${1}" | cut -d ':' -f 2)"
+  access_token="$(grep -Eo 'access_token":".*"' <<<"${1}" | cut -d '"' -f 3)"
+  refresh_token="$(grep -Eo 'refresh_token":".*"' <<<"${1}" | cut -d '"' -f 3)"
+  expires_in="$(grep -Eo 'expires_in":[0-9]*' <<<"${1}" | cut -d ':' -f 2)"
   token_expire_time="$(( $(date +%s) + expires_in ))"
 
   # create dir if not exist
@@ -282,8 +290,8 @@ EOF
 
 function fetch_account_info() {
   response="$(curl --compressed --connect-timeout "${upload_connect_timeout}" -m "${upload_timeout}" --retry "${upload_retries}" -fsSL --stderr - -H "Authorization: Bearer ${access_token}" https://api.imgur.com/3/account/me)"
-  if egrep -q '"success":\s*true' <<<"${response}"; then
-    username="$(egrep -o '"url":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+  if grep -Eq '"success":\s*true' <<<"${response}"; then
+    username="$(grep -Eo '"url":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
     echo "Logged in as ${username}."
     echo "https://${username}.imgur.com"
   else
@@ -293,7 +301,7 @@ function fetch_account_info() {
 
 function delete_image() {
   response="$(curl --compressed -X DELETE  -fsSL --stderr - -H "Authorization: Client-ID ${1}" "https://api.imgur.com/3/image/${2}")"
-  if egrep -q '"success":\s*true' <<<"${response}"; then
+  if grep -Eq '"success":\s*true' <<<"${response}"; then
     echo "Image successfully deleted (delete hash: ${2})." >> "${3}"
   else
     echo "The Image could not be deleted: ${response}." >> "${3}"
@@ -310,10 +318,10 @@ function upload_authenticated_image() {
   fi
 
   # JSON parser premium edition (not really)
-  if egrep -q '"success":\s*true' <<<"${response}"; then
-    img_id="$(egrep -o '"id":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
-    img_ext="$(egrep -o '"link":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4 | rev | cut -d "." -f 1 | rev)" # "link" itself has ugly '\/' escaping and no https!
-    del_id="$(egrep -o '"deletehash":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+  if grep -Eq '"success":\s*true' <<<"${response}"; then
+    img_id="$(grep -Eo '"id":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+    img_ext="$(grep -Eo '"link":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4 | rev | cut -d "." -f 1 | rev)" # "link" itself has ugly '\/' escaping and no https!
+    del_id="$(grep -Eo '"deletehash":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
 
     if [ ! -z "${auto_delete}" ]; then
       export -f delete_image
@@ -323,7 +331,7 @@ function upload_authenticated_image() {
 
     handle_upload_success "https://i.imgur.com/${img_id}.${img_ext}" "https://imgur.com/delete/${del_id}" "${1}"
   else # upload failed
-    err_msg="$(egrep -o '"error":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+    err_msg="$(grep -Eo '"error":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
     test -z "${err_msg}" && err_msg="${response}"
     handle_upload_error "${err_msg}" "${1}"
   fi
@@ -338,10 +346,10 @@ function upload_anonymous_image() {
     response="$(curl --compressed --connect-timeout "${upload_connect_timeout}" -m "${upload_timeout}" --retry "${upload_retries}" -fsSL --stderr - -H "Authorization: Client-ID ${imgur_anon_id}" -F "title=${title}" -F "image=@\"${1}\"" https://api.imgur.com/3/image)"
   fi
   # JSON parser premium edition (not really)
-  if egrep -q '"success":\s*true' <<<"${response}"; then
-    img_id="$(egrep -o '"id":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
-    img_ext="$(egrep -o '"link":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4 | rev | cut -d "." -f 1 | rev)" # "link" itself has ugly '\/' escaping and no https!
-    del_id="$(egrep -o '"deletehash":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+  if grep -Eq '"success":\s*true' <<<"${response}"; then
+    img_id="$(grep -Eo '"id":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+    img_ext="$(grep -Eo '"link":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4 | rev | cut -d "." -f 1 | rev)" # "link" itself has ugly '\/' escaping and no https!
+    del_id="$(grep -Eo '"deletehash":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
 
     if [ ! -z "${auto_delete}" ]; then
       export -f delete_image
@@ -351,7 +359,7 @@ function upload_anonymous_image() {
 
     handle_upload_success "https://i.imgur.com/${img_id}.${img_ext}" "https://imgur.com/delete/${del_id}" "${1}"
   else # upload failed
-    err_msg="$(egrep -o '"error":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+    err_msg="$(grep -Eo '"error":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
     test -z "${err_msg}" && err_msg="${response}"
     handle_upload_error "${err_msg}" "${1}"
   fi
@@ -456,6 +464,7 @@ while [ ${#} != 0 ]; do
     mode="full"
     shift;;
   -o | --open)
+    # shellcheck disable=SC2034
     open="${2}"
     shift 2;;
   -e | --edit)
@@ -511,23 +520,23 @@ if [ -n "${album_title}" ]; then
       -H "Authorization: Client-ID ${imgur_anon_id}" \
       https://api.imgur.com/3/album)"
   fi
-  if egrep -q '"success":\s*true' <<<"${response}"; then # Album creation successful
+  if grep -Eq '"success":\s*true' <<<"${response}"; then # Album creation successful
     echo "Album '${album_title}' successfully created"
-    album_id="$(egrep -o '"id":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
-    del_id="$(egrep -o '"deletehash":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+    album_id="$(grep -Eo '"id":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+    del_id="$(grep -Eo '"deletehash":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
     handle_album_creation_success "http://imgur.com/a/${album_id}" "${del_id}" "${album_title}"
 
     if [ "${login}" = "false" ]; then
       album_id="${del_id}"
     fi
   else # Album creation failed
-    err_msg="$(egrep -o '"error":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
+    err_msg="$(grep -Eo '"error":\s*"[^"]+"' <<<"${response}" | cut -d "\"" -f 4)"
     test -z "${err_msg}" && err_msg="${response}"
     handle_album_creation_error "${err_msg}" "${album_title}"
   fi
 fi
 
-if [ -z "${upload_files}" ]; then
+if [ -z "${upload_files[*]}" ]; then
   upload_files[0]=""
 fi
 
@@ -545,11 +554,13 @@ for upload_file in "${upload_files[@]}"; do
   fi
 
   # get full path
-  img_file="$(cd "$( dirname "${img_file}")" && echo "$(pwd)/$(basename "${img_file}")")"
+  #cd "$(dirname "$(realpath "${img_file}")")"
+  #img_file="$(realpath "${img_file}")"
 
   # check if file exists
-  if [ ! -f "${img_file}" ]; then
+  if ! [ -f "${img_file}" ]; then
     echo "file '${img_file}' doesn't exist !"
+    read -r _
     exit 1
   fi
 
@@ -584,4 +595,4 @@ if [ "${check_update}" = "true" ]; then
   check_for_update
 fi
 
-read dummy
+read -r _
diff --git a/plugins/ipinfo b/plugins/ipinfo
index 70b8007..4ff6f41 100755
--- a/plugins/ipinfo
+++ b/plugins/ipinfo
@@ -5,9 +5,9 @@
 # Shell: POSIX compliant
 # Author: Arun Prakash Jana
 
-IP=`curl -s ifconfig.me`
+IP=$(curl -s ifconfig.me)
 
 whois "$IP"
 echo your external IP address is "$IP"
 
-read dummy
+read -r _
diff --git a/plugins/moclyrics b/plugins/moclyrics
index 1bb0624..d9619f9 100755
--- a/plugins/moclyrics
+++ b/plugins/moclyrics
@@ -18,7 +18,7 @@ out="$(mocp -i)"
 
 # Check if anything is playing
 state=$(echo "$out" | grep "State:" | cut -d' ' -f2)
-if ! [ $state = 'PLAY' ]; then
+if ! [ "$state" = 'PLAY' ]; then
     exit
 fi
 
diff --git a/plugins/mocplay b/plugins/mocplay
index 5f37c37..211a3db 100755
--- a/plugins/mocplay
+++ b/plugins/mocplay
@@ -18,7 +18,8 @@ ret=$cmd
 
 SHUFFLE=0
 
-mocp_add() {
+mocp_add ()
+{
     if [ $SHUFFLE = 1 ]; then
         if [ "$resp" = "y" ]; then
             arr=$(tr '\0' '\n' < "$selection")
@@ -38,7 +39,7 @@ mocp_add() {
         arr2=$(echo "$arr2" | awk 'BEGIN{srand();}{print rand()"\t"$0}' | sort -k1 -n | cut -f2-)
         for entry in $arr2
         do
-            if [ -f "$entry" ] && [ "$(echo "$entry" | grep -v '\.m3u$\|\.pls$')" ]; then
+            if [ -f "$entry" ] &&  echo "$entry" | grep -qv '\.m3u$\|\.pls$' ; then
                 mocp -a "$entry"
             fi
         done
@@ -57,8 +58,8 @@ if [ ! -s "$selection" ] && [ -z "$1" ]; then
 fi
 
 if [ -s "$selection" ]; then
-    echo -n "Work with selection? Enter 'y' to confirm: "
-    read resp
+    printf "Work with selection? Enter 'y' to confirm: "
+    read -r resp
 fi
 
 if [ -z "$ret" ]; then
@@ -68,7 +69,7 @@ else
     # mocp running, check if it's playing
     state=$(mocp -i | grep "State:" | cut -d' ' -f2)
 
-    if [ $state = 'PLAY' ]; then
+    if [ "$state" = 'PLAY' ]; then
         # add to playlist and exit
         mocp_add "$1"
 
diff --git a/plugins/ndiff b/plugins/ndiff
index f5ca0dc..3680627 100755
--- a/plugins/ndiff
+++ b/plugins/ndiff
@@ -10,14 +10,14 @@
 
 selection=${XDG_CONFIG_HOME:-$HOME/.config}/nnn/.selection
 
-if [ -s $selection ]; then
+if [ -s "$selection" ]; then
     arr=$(tr '\0' '\n' < "$selection")
     if [ "$(echo "$arr" | wc -l)" -gt 1 ]; then
          f1="$(echo "$arr" | sed -n '1p')"
          f2="$(echo "$arr" | sed -n '2p')"
          if [ -d "$f1" ] && [ -d "$f2" ]; then
-            dir1=$(mktemp "${TMPDIR:-/tmp}"/nnn-$(basename "$f1").XXXXXXXX)
-            dir2=$(mktemp "${TMPDIR:-/tmp}"/nnn-$(basename "$f2").XXXXXXXX)
+            dir1=$(mktemp "${TMPDIR:-/tmp}"/nnn-"$(basename "$f1")".XXXXXXXX)
+            dir2=$(mktemp "${TMPDIR:-/tmp}"/nnn-"$(basename "$f2")".XXXXXXXX)
             ls -A1 "$f1" > "$dir1"
             ls -A1 "$f2" > "$dir2"
             vimdiff "$dir1" "$dir2"
@@ -27,7 +27,7 @@ if [ -s $selection ]; then
             #     Vim: Warning: Input is not from a terminal
             # xargs -0 -o vimdiff < $selection
 
-            xargs -0 vimdiff +0 < $selection
+            xargs -0 vimdiff +0 < "$selection"
         fi
     else
         echo "needs at least 2 files or directories selected for comparison"
diff --git a/plugins/nmount b/plugins/nmount
index 9fb4e90..3f638bf 100755
--- a/plugins/nmount
+++ b/plugins/nmount
@@ -20,10 +20,9 @@ prompt="device name ['l' lists]: "
 
 lsblk
 
-echo
-echo "Make sure you aren't still in the mounted device."
-echo -n "$prompt"
-read dev
+printf "\nMake sure you aren't still in the mounted device."
+printf "%s" "$prompt"
+read -r dev
 
 while ! [ -z "$dev" ]
 do
@@ -34,11 +33,11 @@ do
     else
         if grep -qs "$dev " /proc/mounts; then
             sync
-            pumount "$dev"
-            if [ "$?" -eq "0" ]; then
+            if pumount "$dev"
+            then
                 echo "$dev" unmounted.
-                udisksctl power-off -b /dev/"$dev"
-                if [ "$?" -eq "0" ]; then
+                if udisksctl power-off -b /dev/"$dev"
+                then
                     echo "$dev" ejected.
                 fi
             fi
@@ -49,6 +48,6 @@ do
     fi
 
     echo
-    echo -n "$prompt"
-    read dev
+    printf "%s" "$prompt"
+    read -r dev
 done
diff --git a/plugins/nwal b/plugins/nwal
index 2f18b08..32d0218 100755
--- a/plugins/nwal
+++ b/plugins/nwal
@@ -6,8 +6,8 @@
 # Author: juacq97
 
 if ! [ -z "$1" ]; then
-    if [ $(mimetype --output-format %m $1 | awk -F '/' '{print $1}') == "image" ]; then
-	    nitrogen --set-zoom-fill --save $1
+    if [ "$(mimetype --output-format %m "$1" | awk -F '/' '{print $1}')" = "image" ]; then
+	    nitrogen --set-zoom-fill --save "$1"
 # If you want a system notification, uncomment the next 3 lines.
 #	     notify-send -a "nnn" "Wallpaper changed!"
 #    else
diff --git a/plugins/oldbigfile b/plugins/oldbigfile
index 4b17405..68f4bed 100755
--- a/plugins/oldbigfile
+++ b/plugins/oldbigfile
@@ -7,10 +7,10 @@
 # Shell: POSIX compliant
 # Author: Arun Prakash Jana
 
-echo -n "Min file size (MB): "
-read size
+printf "Min file size (MB): "
+read -r size
 
-find -size +"$size"M -type f -printf '%A+ %s %p\n' | sort
+find . -size +"$size"M -type f -printf '%A+ %s %p\n' | sort
 
 echo "Press any key to exit"
-read dummy
+read -r _
diff --git a/plugins/pastebin b/plugins/pastebin
index 13fb3e7..61039e6 100755
--- a/plugins/pastebin
+++ b/plugins/pastebin
@@ -6,6 +6,6 @@
 # Author: Arun Prakash Jana
 
 if ! [ -z "$1" ]; then
-    curl -F "f:1=@"$1"" ix.io
-    read input
+    curl -F "f:1=@$1" ix.io
+    read -r _
 fi
diff --git a/plugins/pdfview b/plugins/pdfview
index 17f45e0..2b953b5 100755
--- a/plugins/pdfview
+++ b/plugins/pdfview
@@ -10,7 +10,7 @@
 # Author: Arun Prakash Jana
 
 if ! [ -z "$1" ]; then
-    if [ $(head -c 4 "$1") = "%PDF" ]; then
+    if [ "$(head -c 4 "$1")" = "%PDF" ]; then
         # Convert using pdftotext
         pdftotext -nopgbrk -layout "$1" - | sed 's/\xe2\x80\x8b//g' | $PAGER
 
diff --git a/plugins/pskill b/plugins/pskill
index dcec180..d02c9fa 100755
--- a/plugins/pskill
+++ b/plugins/pskill
@@ -20,10 +20,11 @@ else
     sucmd=: # noop
 fi
 
-echo -n "Enter process name ['defunct' for zombies]: "
-read psname
+printf "Enter process name ['defunct' for zombies]: "
+read -r psname
 
 if ! [ -z "$psname" ]; then
+    # shellcheck disable=SC2009
     cmd="$(ps -ax | grep -iw "$psname" | fzy | sed -e 's/^[ \t]*//' | cut -d' ' -f1)"
     $sucmd kill -9 "$cmd"
 fi
diff --git a/plugins/pywal b/plugins/pywal
index 161bbb5..c8ec867 100755
--- a/plugins/pywal
+++ b/plugins/pywal
@@ -6,8 +6,8 @@
 # Author: juacq97
 
 if ! [ -z "$1" ]; then
-    if [ $(mimetype --output-format %m $1 | awk -F '/' '{print $1}') == "image" ]; then
-	    wal -i $1
+    if [ "$(mimetype --output-format %m "$1" | awk -F '/' '{print $1}')" = "image" ]; then
+	    wal -i "$1"
 # If you want a system notification, uncomment the next 3 lines.
 #	     notify-send -a "nnn" "Wallpaper changed!"
 #    else
diff --git a/plugins/readit b/plugins/readit
index e0058db..4f47992 100755
--- a/plugins/readit
+++ b/plugins/readit
@@ -6,10 +6,10 @@
 # Author: Arun Prakash Jana
 
 if ! [ -z "$1" ]; then
-    tmpf=`basename "$1"`
+    tmpf="$(basename "$1")"
     tmpf="${TMPDIR:-/tmp}"/"${tmpf%.*}"
 
-    if [ $(head -c 4 "$1") = "%PDF" ]; then
+    if [ "$(head -c 4 "$1")" = "%PDF" ]; then
         # Convert using pdftotext
         pdftotext -nopgbrk -layout "$1" - | sed 's/\xe2\x80\x8b//g' > "$tmpf".txt
 
diff --git a/plugins/ringtone b/plugins/ringtone
index d67a409..38c11bd 100755
--- a/plugins/ringtone
+++ b/plugins/ringtone
@@ -13,20 +13,21 @@
 # Author: Arun Prakash Jana
 
 if [ -n "$1" ]; then
-    echo -n "start (hh:mm:ss): "
-    read start
+    printf "start (hh:mm:ss): "
+    read -r start
     st=$(date -d "$start" +%s) || exit 1
 
-    echo -n "end (hh:mm:ss): "
-    read end
+    printf "end (hh:mm:ss): "
+    read -r end
     et=$(date -d "$end" +%s) || exit 1
 
-    if [ $st -ge $et ]; then
-        echo "error: start >= end"
+    if [ "$st" -ge "$et" ]; then
+        printf "error: start >= end "
+        read -r _
         exit 1
     fi
 
-    interval=$(( $et - $st ))
+    interval=$(( et - st ))
 
     outfile=$(basename "$1")
     outfile="${outfile%.*}"_ringtone.mp3
diff --git a/plugins/splitjoin b/plugins/splitjoin
index 60a5408..fcd49de 100755
--- a/plugins/splitjoin
+++ b/plugins/splitjoin
@@ -12,8 +12,8 @@ selection=${XDG_CONFIG_HOME:-$HOME/.config}/nnn/.selection
 resp=s
 
 if [ -s "$selection" ]; then
-    echo -n "press 's' (split current file) or 'j' (join selection): "
-    read resp
+    printf "press 's' (split current file) or 'j' (join selection): "
+    read -r resp
 fi
 
 if [ "$resp" = "j" ]; then
@@ -37,8 +37,8 @@ if [ "$resp" = "j" ]; then
 elif [ "$resp" = "s" ]; then
     if [ -n "$1" ] && [ -f "$1" ]; then
         # a single file is passed
-        echo -n "split size in MB: "
-        read size
+        printf "split size in MB: "
+        read -r size
 
         if [ -n "$size" ]; then
             split -d -b "$size"M "$1" "$1"
diff --git a/plugins/sxiv b/plugins/sxiv
index 2c677fe..1fe81b7 100755
--- a/plugins/sxiv
+++ b/plugins/sxiv
@@ -16,5 +16,5 @@ if command -v sxiv >/dev/null 2>&1; then
     fi
 else
     echo "sxiv missing"
-    read dummy
+    read -r _
 fi
diff --git a/plugins/thumb b/plugins/thumb
index 10bb651..8882115 100755
--- a/plugins/thumb
+++ b/plugins/thumb
@@ -12,6 +12,6 @@ if ! [ -z "$1" ]; then
         lsix "$1"
     fi
 
-    echo -n "Press any key to exit..."
-    read dummy
+    printf "Press any key to exit..."
+    read -r _
 fi
diff --git a/plugins/transfer b/plugins/transfer
index 7201b0b..05992a3 100755
--- a/plugins/transfer
+++ b/plugins/transfer
@@ -7,9 +7,9 @@
 
 if ! [ -z "$1" ]; then
     # Upload the file, show the download link and wait till user presses any key
-    curl -s --upload-file "$1" https://transfer.sh/`basename "$1"`
+    curl -s --upload-file "$1" https://transfer.sh/"$(basename "$1")"
     echo
-    read input
+    read -r _
 
     # To write download link to "$1".loc and exit
     # curl -s --upload-file "$1" https://transfer.sh/`basename "$1"` -o `basename "$1"`.loc
diff --git a/plugins/uidgid b/plugins/uidgid
index 37d832d..a73acae 100755
--- a/plugins/uidgid
+++ b/plugins/uidgid
@@ -5,4 +5,5 @@
 # Shell: POSIX compliant
 # Author: Arun Prakash Jana, superDuperCyberTechno
 
+# shellcheck disable=SC2012
 ls -lah --group-directories-first | less
diff --git a/plugins/upgrade b/plugins/upgrade
index 8dd3b5a..d166991 100755
--- a/plugins/upgrade
+++ b/plugins/upgrade
@@ -6,10 +6,10 @@
 # Author: Arun Prakash Jana
 # NOTE: This script installs a package, should be issued with admin privilege
 
-cur=`nnn -v`
-new=`curl -s "https://github.com/jarun/nnn/releases/latest" | grep -Eo "[0-9]+\.[0-9]+"`
+cur="$(nnn -v)"
+new="$(curl -s "https://github.com/jarun/nnn/releases/latest" | grep -Eo "[0-9]+\.[0-9]+")"
 
-if [ $cur_ver == $new_ver ]; then
+if [ "$cur" = "$new" ]; then
     echo 'Already at latest version'
     exit 0
 fi
@@ -18,7 +18,7 @@ fi
 curl -Ls -O "https://github.com/jarun/nnn/releases/download/v$new/nnn_$new-1_debian9.amd64.deb"
 
 # install it
-sudo dpkg -i nnn_$new-1_debian9.amd64.deb
+sudo dpkg -i nnn_"$new"-1_debian9.amd64.deb
 
 # remove the file
-rm -rf nnn_$new-1_debian9.amd64.deb
+rm -rf nnn_"$new"-1_debian9.amd64.deb
diff --git a/plugins/vidthumb b/plugins/vidthumb
index a6eb0e4..6411eb1 100755
--- a/plugins/vidthumb
+++ b/plugins/vidthumb
@@ -23,5 +23,5 @@ lsix .nthumbs/*
 # remove the thumbnails
 rm -rf .nthumbs
 
-echo -n "Press any key to exit..."
-read dummy
+printf "Press any key to exit..."
+read -r _