The Linux Daily

Compare Output of Command and Match to CSV List or File

The following script provides a method for scanning the output of a command, matching it in another list, and performing an action. The example script, install.sh, shown is using the lsusb command to scan USB devices inserted against the known-devices.csv file and perform an action. Here’s how it looks in motion:

./install.sh

* This script will automatically determine the wireless
* adapter and install the appropriate drivers.

Detected: Asus WL-167g
Running Script in 3rd Field of CSV... OKAY!

Scripting language is pretty much self-documenting so I won’t bother explaining too much. If you have questions or suggestions, please let me know. The following script is flexible and can be used in many different situations so I encourage you to customize it to fit your needs. Enjoy!

install.sh: The main script that is ran to try and match the output of the lsusb command with another files list and act accordingly.

#!/bin/sh

# Create tmp files for verification along the way
touch tmp
touch tmp2

echo
echo "* This script will automatically determine the wireless"
echo "* adapter and install the appropriate drivers."
echo

# Run lsusb and grab only the prod/vend id field
lsusb | cut -d' ' -f 6 | while read line
do
   # Use grep to search for $line of lsusb output in known-devices.csv file and save to tmp
   grep "$line" known-devices.csv > tmp
   if [ $? = 0 ]; then
      echo -n "Detected: "

      # Use awk to print only field 2 of the tmp file (also field 2 of known-devices.csv)
      awk 'BEGIN{FS=",";}
      {
         {print $2}
      }' < tmp
      
      # Prepare and execute the third field of the known-devices.csv file
      echo -n "Running Script in 3rd Field of CSV... "
      cut -d',' -f 3 tmp > tmp2
      chmod +x tmp2
      ./tmp2
   fi
done

# Check the tmp2 file and see if it is empty.  If so, display error.
if [ `ls -l tmp2 | awk '{print $5}'` -eq 0 ]
then
  echo "No known devices found."
fi

known-devices.csv: The comma separated file in which the install.sh uses to check against. In this particular example, the prod/vend usb ID is the first field, the friendly name is in the second field, and the installation command is in the third field.

USB ID   | USB NAME     | DRIVER INSTALL COMMAND(S)                            |
--------------------------------------------------------------------------------
0ace:1215, IOGear GWU523, lib/zd1211/zd1211rw_install.sh
0b05:1723, Asus WL-167g , lib/rt73/rt73_install.sh

rt73_install.sh: This is the script that is called by the known-devices.csv file above. If there was a simple one-line command, you could specify it in the third field of the known-devices.csv file.

#!/bin/sh

   insmod rt73.ko > /dev/null 2> /dev/null
   if [ $? -eq 0 ] ; then
      echo "OKAY!"
    (
        # These are optional permanent install commands that will be ran upon
        # successful completion of previous command.
        mkdir -p lib/modules/`uname -r`/kernel/drivers/net/wireless/rt73/
        cp rt73.ko lib/modules/`uname -r`/kernel/drivers/net/wireless/rt73/rt73.ko
     )  > /dev/null 2> /dev/null
   else
      echo "FAILED!"
      echo -n "Error: Driver already installed, wasn't found, or failed to insert."
      echo "Check 'lsmod' and 'dmesg' for debugging information."
      exit
   fi