Yrurtj

I have a variable $line, which can contain any of the following strings:

• 
  line="READ CACHE IS: ENABLED"


• 
  line="BLOCKS READ CACHE AND SENT TO INITIATOR = 2489338280"


• line="ECC REREADS/ ERRORS ALGORITHM PROCESSED UNCORRECTED"


• 
  line="READ: 2513550726 22 0 2513550748 2513550748 27768.965 0"


• 
  line="1 RAW_READ_ERROR_RATE PO-R-- 100 100 016 - 0"


• 
  line="0x22 GPL R/O 1 READ STREAM ERROR LOG"


• line="READ: DISABLED"

I have a script that compares the $line variable against some patterns:

if [[ ${line} == *"RAW_READ_ERROR_RATE"* ]] || 

[[ ${line} == "READ:"* ]] && 

[[ ${line} != *"READ: DISABLED"* ]]; then



devReadErr=$(echo "$line" | awk '{print $8}')

Herein lies the problem. The colon is screwing everything up. I've tried every possible way of formatting the pattern to satisfy both possibilities of line="1 RAW_READ_ERROR_RATE PO-R-- 100 100 016 - 0" or line="READ: 2513550726 22 0 2513550748 2513550748 27768.965 0" When I escape the : as shown above. I can satisfy line="1 RAW_READ_ERROR_RATE PO-R-- 100 100 016 - 0" but not line="READ: 2513550726 22 0 2513550748 2513550748 27768.965 0". If I take away the escape, then I satisfy line="READ: 2513550726 22 0 2513550748 2513550748 27768.965 0"not line="1 RAW_READ_ERROR_RATE PO-R-- 100 100 016 - 0"

Sample Run 1:

line="1 RAW_READ_ERROR_RATE PO-R-- 100 100 016 - 0"



        if [[ ${line} == *"RAW_READ_ERROR_RATE"* ]] || 

           [[ ${line} == "READ:"* ]] && 

           [[ ${line} != *"READ: DISABLED"* ]]; then



          devReadErr=$(echo "$line" | awk '{print $8}')

        fi



echo $devReadErr

Output of Run 1:

0

Sample Run 2:

line="READ: 2513550726 22 0 2513550748 2513550748 27768.965 0"



        if [[ ${line} == *"RAW_READ_ERROR_RATE"* ]] || 

           [[ ${line} == "READ:"* ]] && 

           [[ ${line} != *"READ: DISABLED"* ]]; then



          devReadErr=$(echo "$line" | awk '{print $8}')

        fi



echo $devReadErr

Output of Run 2:

<null>

Sample Run 3:

line="READ: 2513550726 22 0 2513550748 2513550748 27768.965 0"



        if [[ ${line} == *"RAW_READ_ERROR_RATE"* ]] || 

           [[ ${line} == "READ:"* ]] && 

           [[ ${line} != *"READ: DISABLED"* ]]; then



          devReadErr=$(echo "$line" | awk '{print $8}')

        fi



echo $devReadErr

Output of Run 3:

0

How do I get the best of both worlds?

You should remove the in front of : in that second test, or it will try to match against a literal character.

These are not regular expression matches you are doing, but shell globbing pattern matches (just as on the command line when you are using * in patterns). This doesn't really matter in this case.

I'm assuming that you'd like to extract the 20 from the two first strings and store it in devReadErr, but not when the line reads READ: DISABLED. This is exactly what your code does if the is removed:

if  [[ ${line} == *"RAW_READ_ERROR_RATE"* ]] ||

    [[ ${line} == "READ:"* ]] &&

    [[ ${line} != *"READ: DISABLED"* ]]; then



    devReadErr=$(echo "$line" | awk '{print $2}')



fi

Another way to do the same thing:

if [[ "$line" != *'DISABLED' ]]; then

    devReadErr=${line##* }

fi

This extracts the number as the string after the last space character in $line if the string does not end with the word DISABLED. This avoids the echo and awk.

If this is part of a larger loop that parses a file line by line, then I would suggest writing it in awk or some other language designed to parse text. See, e.g., Why is using a shell loop to process text considered bad practice?.

I suspect you want:

if [[ $line = *RAW_READ_ERROR_RATE* || 

      $line = READ:* && $line != *"READ: DISABLED"* ]]; then

The && [[...]] operator has precedence over || but the && shell operator has same precedence as ||.

Or to make it explicit:

if [[ $line = *RAW_READ_ERROR_RATE* || 

      ($line = READ:* && $line != *"READ: DISABLED"*) ]]; then

Or using the &&/|| shell operators and multiple [[...]]s:

if [[ $line = *RAW_READ_ERROR_RATE* ]] || { 

      [[ $line = READ:* ]] && [[ $line != *"READ: DISABLED"* ]]; }; then

Or change the order:

if [[ $line = READ:* ]] && [[ $line != *"READ: DISABLED"* ]] ||

   [[ $line = *RAW_READ_ERROR_RATE* ]]; then

Or use a pattern that matches all:

if [[ $line = @(*RAW_READ_ERROR_RATE*|!(!(*READ:*)|*READ: DISABLED*)) ]]; then

Without the parenthesis/braces, yours is read as:

if [[ ($line = *RAW_READ_ERROR_RATE* || 

     $line = READ:*) && $line != *"READ: DISABLED"* ]]; then

That shouldn't prevent it from matching lines that contain RAW_READ_ERROR_RATE though provided they don't contain READ: DISABLED.