In scripts/common.sh line 27:
    str="${@: -1}"; inputbox=false
        ^--------^ SC2124 (warning): Assigning an array to a string! Assign as array, or use * instead of @ to concatenate.
         ^------^ SC3057 (warning): In POSIX sh, string indexing is undefined.


In scripts/common.sh line 31:
            if [ $i -eq $((${argc}-1)) ]; then
                           ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In scripts/common.sh line 36:
            ((i++))
            ^-----^ SC3006 (warning): In POSIX sh, standalone ((..)) is undefined.
               ^-- SC3018 (warning): In POSIX sh, ++ is undefined.


In scripts/common.sh line 42:
        width=$((${width}+15))
                 ^------^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In scripts/common.sh line 43:
        height=$((${height}+2))
                  ^-------^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In scripts/common.sh line 46:
    if [ $found = false ]; then
         ^----^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 
    if [ "$found" = false ]; then


In scripts/common.sh line 49:
        dialog "${options[@]}"
                ^-----------^ SC3054 (warning): In POSIX sh, array references are undefined.


In scripts/common.sh line 54:
    str="${@: -1}"; inputbox=false
        ^--------^ SC2124 (warning): Assigning an array to a string! Assign as array, or use * instead of @ to concatenate.
         ^------^ SC3057 (warning): In POSIX sh, string indexing is undefined.


In scripts/common.sh line 58:
            if [ $i -eq $((${argc}-1)) ]; then
                           ^-----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In scripts/common.sh line 63:
            ((i++))
            ^-----^ SC3006 (warning): In POSIX sh, standalone ((..)) is undefined.
               ^-- SC3018 (warning): In POSIX sh, ++ is undefined.


In scripts/common.sh line 69:
        width=$((${width}+15))
                 ^------^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In scripts/common.sh line 72:
    if [ $found = false ]; then
         ^----^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 
    if [ "$found" = false ]; then


In scripts/common.sh line 76:
        whiptail "${options[@]}"
                  ^-----------^ SC3054 (warning): In POSIX sh, array references are undefined.


In scripts/common.sh line 81:
    options=(); found=false
            ^-- SC3030 (warning): In POSIX sh, arrays are undefined.


In scripts/common.sh line 84:
            options+=("${height}")
            ^-----^ SC3024 (warning): In POSIX sh, += is undefined.
                     ^-----------^ SC3030 (warning): In POSIX sh, arrays are undefined.


In scripts/common.sh line 85:
            options+=("${width}")
            ^-----^ SC3024 (warning): In POSIX sh, += is undefined.
                     ^----------^ SC3030 (warning): In POSIX sh, arrays are undefined.


In scripts/common.sh line 90:
        options+=("${item}")
        ^-----^ SC3024 (warning): In POSIX sh, += is undefined.
                 ^---------^ SC3030 (warning): In POSIX sh, arrays are undefined.


In scripts/common.sh line 97:
    whiptail "${options[@]}"
              ^-----------^ SC3054 (warning): In POSIX sh, array references are undefined.


In scripts/common.sh line 103:
    dialog "${options[@]}"
            ^-----------^ SC3054 (warning): In POSIX sh, array references are undefined.


In scripts/common.sh line 107:
    width=$(echo "$1" | wc -c)
            ^---------------^ SC2000 (style): See if you can use ${#variable} instead.


In scripts/common.sh line 108:
    echo $((${width}+8))
            ^------^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In scripts/common.sh line 113:
    for (( i = 0; i < ${#str}; i++ )); do
    ^-^ SC3005 (warning): In POSIX sh, arithmetic for loops are undefined.
                                ^-- SC3018 (warning): In POSIX sh, ++ is undefined.


In scripts/common.sh line 114:
        if [ "${str:$i:1}" = '\' ] && [ "${str:$((i+1)):1}" = 'n' ]; then
              ^---------^ SC3057 (warning): In POSIX sh, string indexing is undefined.
                              ^-- SC1003 (info): Want to escape a single quote? echo 'This is how it'\''s done'.
                                         ^---------------^ SC3057 (warning): In POSIX sh, string indexing is undefined.


In scripts/common.sh line 121:
        ((count++))
        ^---------^ SC3006 (warning): In POSIX sh, standalone ((..)) is undefined.
               ^-- SC3018 (warning): In POSIX sh, ++ is undefined.


In scripts/common.sh line 125:
        echo $(($count+8))
                ^----^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In scripts/common.sh line 132:
    newlines=$(printf "$1" | grep -c $'\n')
                      ^--^ SC2059 (info): Don't use variables in the printf format string. Use printf '..%s..' "$foo".
                                     ^---^ SC3003 (warning): In POSIX sh, $'..' is undefined.


In scripts/common.sh line 133:
    chars=$(echo "$1" | wc -c)
            ^---------------^ SC2000 (style): See if you can use ${#variable} instead.


In scripts/common.sh line 138:
    echo $((6+${height}))
              ^-------^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In scripts/common.sh line 142:
    newlines=$(printf "$1" | grep -c $'\n')
                      ^--^ SC2059 (info): Don't use variables in the printf format string. Use printf '..%s..' "$foo".
                                     ^---^ SC3003 (warning): In POSIX sh, $'..' is undefined.


In scripts/common.sh line 143:
    chars=$(echo "$1" | wc -c)
            ^---------------^ SC2000 (style): See if you can use ${#variable} instead.


In scripts/common.sh line 148:
    echo $((4+${height}))
              ^-------^ SC2004 (style): $/${} is unnecessary on arithmetic variables.


In scripts/common.sh line 152:
    export dialogBox=${1}
                     ^--^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 
    export dialogBox="${1}"

For more information:
  https://www.shellcheck.net/wiki/SC2124 -- Assigning an array to a string! A...
  https://www.shellcheck.net/wiki/SC3003 -- In POSIX sh, $'..' is undefined.
  https://www.shellcheck.net/wiki/SC3005 -- In POSIX sh, arithmetic for loops...