In /logs/firmware/patool_extraction/DUMP/mtdblock8_unblob_extracted/mtdblock8_extract/0-9650176.squashfs_v4_le_extract/sbin/wpsApCheck.sh line 13:

		one=$( singleProbeLink && echo -n "0" || echo -n "1" )

                                               ^-- SC3037 (warning): In POSIX sh, echo flags are undefined.

                                                              ^-- SC3037 (warning): In POSIX sh, echo flags are undefined.

In /logs/firmware/patool_extraction/DUMP/mtdblock8_unblob_extracted/mtdblock8_extract/0-9650176.squashfs_v4_le_extract/sbin/wpsApCheck.sh line 14:

		[ "$other" == "$one" ] && return "$one"

                           ^-- SC3014 (warning): In POSIX sh, == in place of = is undefined.

In /logs/firmware/patool_extraction/DUMP/mtdblock8_unblob_extracted/mtdblock8_extract/0-9650176.squashfs_v4_le_extract/sbin/wpsApCheck.sh line 16:

		other=$( singleProbeLink && echo -n "0" || echo -n "1" )

                                                 ^-- SC3037 (warning): In POSIX sh, echo flags are undefined.

                                                                ^-- SC3037 (warning): In POSIX sh, echo flags are undefined.

In /logs/firmware/patool_extraction/DUMP/mtdblock8_unblob_extracted/mtdblock8_extract/0-9650176.squashfs_v4_le_extract/sbin/wpsApCheck.sh line 17:

		[ "$other" == "$one" ] && return "$one"

                           ^-- SC3014 (warning): In POSIX sh, == in place of = is undefined.

In /logs/firmware/patool_extraction/DUMP/mtdblock8_unblob_extracted/mtdblock8_extract/0-9650176.squashfs_v4_le_extract/sbin/wpsApCheck.sh line 23:

[ $wire_link -eq 1 ] && exit 1

  ^--------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 

[ "$wire_link" -eq 1 ] && exit 1

In /logs/firmware/patool_extraction/DUMP/mtdblock8_unblob_extracted/mtdblock8_extract/0-9650176.squashfs_v4_le_extract/sbin/wpsApCheck.sh line 27:

[ -f "/tmp/udhcpd.pid" ] && udhcpd_pid=`cat /tmp/udhcpd.pid` || exit 1

                                       ^-------------------^ SC2006 (style): Use $(...) notation instead of legacy backticks `...`.

Did you mean: 

[ -f "/tmp/udhcpd.pid" ] && udhcpd_pid=$(cat /tmp/udhcpd.pid) || exit 1

In /logs/firmware/patool_extraction/DUMP/mtdblock8_unblob_extracted/mtdblock8_extract/0-9650176.squashfs_v4_le_extract/sbin/wpsApCheck.sh line 31:

	kill -SIGUSR1 $udhcpd_pid

                      ^---------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 

	kill -SIGUSR1 "$udhcpd_pid"

In /logs/firmware/patool_extraction/DUMP/mtdblock8_unblob_extracted/mtdblock8_extract/0-9650176.squashfs_v4_le_extract/sbin/wpsApCheck.sh line 32:

	ip_mask=`tdb get Network LeaseStart_ss | cut -d'.' -f1-3`

                ^-- SC2006 (style): Use $(...) notation instead of legacy backticks `...`.

Did you mean: 

	ip_mask=$(tdb get Network LeaseStart_ss | cut -d'.' -f1-3)

In /logs/firmware/patool_extraction/DUMP/mtdblock8_unblob_extracted/mtdblock8_extract/0-9650176.squashfs_v4_le_extract/sbin/wpsApCheck.sh line 33:

	lease_str=`/usr/bin/dumpleases -f /tmp/udhcpd.leases | grep $ip_mask`

                  ^-- SC2006 (style): Use $(...) notation instead of legacy backticks `...`.

                                                                    ^------^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 

	lease_str=$(/usr/bin/dumpleases -f /tmp/udhcpd.leases | grep "$ip_mask")

For more information:

  https://www.shellcheck.net/wiki/SC3014 -- In POSIX sh, == in place of = is ...

  https://www.shellcheck.net/wiki/SC3037 -- In POSIX sh, echo flags are undef...

  https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...