Comparing two bash variables

Question

I am trying to write a simple Bash script that shows the difference between two variables, with the assumption that both variables contain identical parameters with different values. Look at $sam and $pish variables. They are identical, except parameter driver_mode is 1 in $sam , and 2 in $pish . To do this comparison, I store each variable into a separate array, and then compare each element one by one.

#!/bin/bash

sam="driver_mode=2 firmware_path=/home/release/firmware/ onebox_zone_enabled=0x10001 ta_aggr=4 skip_fw_load=0 fw_load_mode=1 sdio_clock=40000 enable_antenna_diversity=0 coex_mode=1 obm_ant_sel_val=2 wlan_rf_power_mode=0 bt_rf_power_mode=0 zigb_rf_power_mode=0 country_code=840  bt_rf_tx_power_mode=1 bt_rf_rx_power_mode=0"

pish="driver_mode=1 firmware_path=/home/release/firmware/ onebox_zone_enabled=0x10001 ta_aggr=4 skip_fw_load=0 fw_load_mode=1 sdio_clock=40000 enable_antenna_diversity=0 coex_mode=1 obm_ant_sel_val=2 wlan_rf_power_mode=0 bt_rf_power_mode=0 zigb_rf_power_mode=0 country_code=840  bt_rf_tx_power_mode=1 bt_rf_rx_power_mode=0"

read -r -a array_old <<< "$sam"

read -r -a array_new <<< "$pish"

for index in "${!array_old[@]}"; do
    if [[ ${array_old[index]} -ne ${array_new[index]} ]]; then
        echo ${array_old[index]} 'to' ${array_new[index]}     
    fi
done

Running the above bash script gives me error:

./test: line 12: firmware_path=/home/release/firmware/: syntax error: operand expected (error token is "/home/release/firmware/")

Answer 1

The -ne operator is an integer comparison operator . To compare strings use != :

for index in "${!array_old[@]}"; do
  if [[ ${array_old[index]} != "${array_new[index]}" ]]; then
    echo ${array_old[index]} 'to' ${array_new[index]}     
  fi
done