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Bash script to diff two arrays

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# 1  
Old 02-08-2016
Bash script to diff two arrays
Hi,

I am quite scripting illiterate and have been trying to write a bash script to compare to two files which i have populated in two seperate arrays as below and confirmed that all the files are loaded into the array.

Code:
IFS=$'\n'
filea=($(find /var/tmp/dir1 -type f -follow -print))
fileb=($(find /var/tmp/dir2 -type f -follow -print))
unset IFS

both directories and files are the same, I want to run a loop over both arrays and then i then want to run the following command and put the output into a variable
Code:
diff -a --suppress-common-lines -y $filea $fileb

is this how i should be setting the variable or should i be doing something different?
Code:
diffout=($(diff -a --suppress-common-lines -y $filea $fileb))

i would then run an IF statement to check if the variable is empty
Code:
if [-n "$diffout" ];then
yes | cp -f $filea /var/tmp/dir3

my overall script so far

Code:
IFS=$'\n'		
			filea=($(find /var/tmp/dir1 -type f -follow -print))
			fileb=($(find /var/tmp/dir2 -type f -follow -print))
		unset IFS
		
		for afile in "{$filea[@]}"
		do
		for bfile in "{$fileb[@]}"
		do
		diffout=($(diff -a --suppress-common-lines -y $filea $fileb))
				
		done
		
		if [-n "$diffout" ];then
			yes | cp -f $filea /var/tmp/destination	
		
		done

# 2  
Old 02-08-2016
There are a few errors, some syntax:
  • $filea instead of correct "$afile" (the name is wrong, but also the quoting is essential)
  • {$ instead of ${
  • if, but no closing then
  • [-n instead of [ -n (the sspppace must be there
  • diffout=(... creates and array, yet you test for "$diffout" a plain variable..
  • What is with the yes piping in to cp -f (which is force mode in itself)
# 3  
Old 02-08-2016
am i any closer?

apologies i am really still learning how to do scripting in general

Code:
        IFS=$'\n'        
            filea=($(find /var/tmp/dir1 -type f -follow -print))
            fileb=($(find /var/tmp/dir2 -type f -follow -print))
        unset IFS
        
        for afile in "${filea[@]}"

        do

        for bfile in "${fileb[@]}"

        do
            diffout=($(diff -a --suppress-common-lines -y "$afile" "$bfile"))
                
        
        if [ ${#diffout[@]} -eq 0 ]; then

        fi
        
        else
            cp -f $afile /var/tmp/destination
        fi
        
        done

# 4  
Old 02-08-2016
Still some syntax:
- two fis for one ifonly
- one done only for two dos

Some semantics:
- no statements in the then branch

Some logics:
- the entire script fails if there's a single file disturbing the sequence of files in either directory
- Unless needed elsewhere, the diffout array doesn't make sense. Try if diff ...
# 5  
Old 02-08-2016
Code:
        IFS=$'\n'        
            filea=($(find /var/tmp/dir1 -type f -follow -print))
            fileb=($(find /var/tmp/dir2 -type f -follow -print))
        unset IFS
        
        for afile in "${filea[@]}"

        do

        for bfile in "${fileb[@]}"

        do
            diffout=($(diff -a --suppress-common-lines -y "$afile" "$bfile"))
                
        
        if [ ${#diffout[@]} -eq 0 ]; then

        echo "No Difference in Configuration Detected"

        fi
        
        else
            cp -f $afile /var/tmp/destination
        
        done
        done

Basically what im looking for differences in configuration files and this would just be text, i was hoping with the
Code:
diffout

to check if it was empty or not, if empty then goto the next file otherwise copy
Code:
$filea

to the specified directory, once copied goto the next file.

apologies if i am just not getting it but like i said i know just the basics of scripting and still yet to learn proper logic etc
# 6  
Old 02-08-2016
Not sure what you want to test - files to be empty or the difference between two of them to disappear?

The residual fi needs to include the else (come after it).
# 7  
Old 02-08-2016
Some plain demo syntax:
Code:
num=2
val=1
another_value=3

# Since we KNOW for 100% its all numbers, no quotes are required around those variables
# If there is the SLIGHTEST chance (parsing an unkown file for example) ALL the variables containing content of those unkown file/lines should be quoted!

if [ $num -eq $val ]
then
	echo "I'm a 'If condition'"
elif [ $num -eq $another_value ]
then
	echo "I'm in 'elif condition'"
else
	echo "I'm in 'else statement'"
fi

for ITEM in *;do
	echo "Found $ITEM in $PWD"
done

Example output from within my tempdir:
Code:
0 ~/tmp/build $ bash ../jlykke

I'm in 'else statement'
Found "kernel" in /home/sea/tmp/build

Hope this helps
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