Shell script, get/extract mac address from console output of command after "MAC: "

Question

I'm trying to automatically pull out the mac address of a arduino device using a shell script, and need some help how to do this.

This is the output returned by the command:

Opening /dev/cu.SLAB_USBtoUART @ 115200...
Connecting to ESP32 ROM, attempt 1 of 10...
Connecting to ESP32 ROM, attempt 2 of 10...
  Connected, chip: ESP32D0WDQ5 R1
efuse_wr_disable     : 0x0084
efuse_rd_disable     : 0x1
flash_crypt_cnt      : 0x01 (WD)
WIFI_MAC_Address     : 0xaaaaaaaaaaaaaa (MAC: aa:bb:cc:dd:ee:ff)
SPI_pad_config_hd    : 0x0
chip_package         : 0x1
cpu_freq_low         : 0x0

I am able to capture this into a shell script variable, but having a hard time trying to extract just the mac address of aa:bb:cc:dd:ee:ff

The output will always be the exact same, (MAC: followed by the 17 characters that make up the mac address, then a closing )

Can someone please help me with a command I can use on a variable all this output is stored in, to get just the aa:bb:cc:dd:ee:ff portion? I've been searching and trying for hours without luck, thank you!!

Answer 1

You can try awk

my_command_with_output | awk -F'[()]' '/^WIFI_MAC_Address/{sub(/^.*: /,"");print $1}'

You can put it in a varialbe

variable=$(my_command_with_output | awk -F'[()]' '/^WIFI_MAC_Address/{sub(/^.*: /,"");print $1}')

Print out the content of the variable.

echo "$variable"

Output

aa:bb:cc:dd:ee:ff

Answer 2

If I understand you correctly:

echo "$var" |  grep -o "..:..:..:..:.."

Output:

aa:bb:cc:dd:ee:ff

Answer 3

You can capture any valid MAC (with a leading space) with this regex:

command  |   grep -oE '([ :][[:xdigit:]]{2}){6}'

Or, in bash shell:

$ regex='(([[:xdigit:]]{2}:){5}([[:xdigit:]]{2}))';
$ [[ $var =~ $regex ]] &&  printf '%s\n' "${BASH_REMATCH[1]}"
aa:bb:cc:dd:ee:ff