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Top Forums Shell Programming and Scripting Stupid question to check if variable is empty Post 302925922 by rbatte1 on Thursday 20th of November 2014 08:20:28 AM
Old 11-20-2014
It seems wasteful to fire up another process for this (and for incrementing counters) especially if there is an input file possibly thousands of lines long, in which case this will be expensive.

Could you try:-
Code:
if [ -z "$title" -o "$title" = " " ]
then
   echo "Null or space"
else
   echo "Contents"
fi

If this works, fit it to your script. It might be worth adjusting the loop too to something more like this:-
Code:
#Check if values in job card are not empty
grep "TITLE:" $filename | cut -d ":" -f3 | while read title         # Handle multiple records if required
do
   if [ -z "$title" -o "$title" = " " ]
   then 
      echo "10:Title Empty" ":Fail"
      ((itemfailed=$itemfailed+1))                                  # In-process
   else
      echo "10:Title description present." ":Pass"
      ((itempassed=$itempassed+1))
   fi
done >> $rptfile                                                    # All output from loop appended to this file

One thing to be aware of is that the variable being read in the loop, i.e. $title will be null when you come out of the loop. You can get round this like this if you need to know the last value:-
Code:
echo "a\nb\nc" | while read val
do
   echo "Read $val"
   VAL=$val
done
echo "\$val is \"$val\""
echo "\$VAL is \"$VAL\""

Output will be:-
Code:
Read a
Read b
Read c
$val is ""
$VAL is "c"


I hope that this helps,
Robin
 

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MAX(3)									 1								    MAX(3)

max - Find highest value

SYNOPSIS
mixed max (array $values) DESCRIPTION
mixed max (mixed $value1, mixed $value2, [mixed $...]) If the first and only parameter is an array, max(3) returns the highest value in that array. If at least two parameters are provided, max(3) returns the biggest of these values. Note Values of different types will be compared using the standard comparison rules. For instance, a non-numeric string will be com- pared to an integer as though it were 0, but multiple string values will be compared alphanumerically. The actual value returned will be of the original type with no conversion applied. PARAMETERS
o $values - An array containing the values. o $value1 - Any comparable value. o $value2 - Any comparable value. o $... - Any comparable value. RETURN VALUES
max(3) returns the parameter value considered "highest" according to standard comparisons. If multiple values of different types evaluate as equal (e.g. 0 and 'abc') the first provided to the function will be returned. EXAMPLES
Example #1 Example uses of max(3) <?php echo max(2, 3, 1, 6, 7); // 7 echo max(array(2, 4, 5)); // 5 // The string 'hello' when compared to an int is treated as 0 // Since the two values are equal, the order they are provided determines the result echo max(0, 'hello'); // 0 echo max('hello', 0); // hello // Here we are comparing -1 < 0, so 'hello' is the highest value echo max('hello', -1); // hello // With multiple arrays of different lengths, max returns the longest $val = max(array(2, 2, 2), array(1, 1, 1, 1)); // array(1, 1, 1, 1) // Multiple arrays of the same length are compared from left to right // so in our example: 2 == 2, but 5 > 4 $val = max(array(2, 4, 8), array(2, 5, 1)); // array(2, 5, 1) // If both an array and non-array are given, the array will be returned // as comparisons treat arrays as greater than any other value $val = max('string', array(2, 5, 7), 42); // array(2, 5, 7) // If one argument is NULL or a boolean, it will be compared against // other values using the rule FALSE < TRUE regardless of the other types involved // In the below example, -10 is treated as TRUE in the comparison $val = max(-10, FALSE); // -10 // 0, on the other hand, is treated as FALSE, so is "lower than" TRUE $val = max(0, TRUE); // TRUE ?> SEE ALSO
min(3), count(3). PHP Documentation Group MAX(3)
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