[SOLVED] UNIX FOR loop to read a variable with multiple values

Shell Programming and Scripting
1

Hi,

I have a variable which stores file names as a result of find command. I need to delete all these files one by one, i.e. by a loop. Can anyone tell me how can it be done?
The variable

f2d

has the file names like these

 
abc.txt
bcd.txt
fff.txt
gef.txt

Now I have used a loop as below;

 
for i in $f2d
do
   rm $i
done

But this is not giving me the desired output. It is taking all the files at a time and not interating through the loop. Please advise.

I am using

# ! /bin/sh
2

It is working as you expected..

just check..

$ echo $f2d
abc.txt bcd.txt fff.txt gef.txt

$ echo "$f2d"
abc.txt
bcd.txt
fff.txt
gef.txt

$ for i in $f2d
do
echo $i
echo "dd"
done

abc.txt
dd
bcd.txt
dd
fff.txt
dd
gef.txt
dd

$ for i in "$f2d"
do
echo $i
echo "dd"
done

abc.txt bcd.txt fff.txt gef.txt
dd
3

Its still not working for me.

 
for i in $f2d
do 
   echo " Arg is = $i "
done

The output is

 
Arg is = abc.txt
bcd.txt
fff.txt
gef.txt

The

Arg is =

should appear each time a file name is written. Please suggest what went wrong.

5

And it does:

ran:/home/vbe $ echo $0
sh
ran:/home/vbe $ echo "$f2d"
abc.txt
bcd.txt
fff.txt
gef.txt
ran:/home/vbe $ for i in $f2d^Jdo ^J   echo " Arg is = $i "^Jdone
 Arg is = abc.txt 
 Arg is = bcd.txt 
 Arg is = fff.txt 
 Arg is = gef.txt 
ran:/home/vbe $

As pamu already shown previously...
So if it does not work, then you havent given us the exact value in the variable I suspect a line feed or newline with end of line... OR:
Look again carefully at pamu's post... specially the second part... doesnt that remind you of something?

ran:/home/vbe $ for i in "$f2d"^Jdo ^J   echo " Arg is = $i "^Jdone
 Arg is = abc.txt
bcd.txt
fff.txt
gef.txt
6

My variable looks like this

 
f2d=$(find ./ -type d ! -name . -prune -o -mtime +$NUM_DAYS -name '*.dat' )
 
echo "Files to delete =$f2d"

Output is

 
Files to delete =./fgh.dat
./ggg.dat
./sss.dat
./test_2

And the FOR loop is still not working. Please advise.

7

And what does just

echo $f2d

outputs?

8

The output for

echo $f2d

is

 
./fgh.dat
./ggg.dat
./sss.dat
./test_2
9

You must have altered IFS somewhere, since that string isn't even splitting while unquoted.

10

Yes, I am using IFS at an earlier place and it is very much required there. The below piece of code shows that.

 
IFS=' '
while read -r dir; do
(
        cd $dir
        files2del=$(find ./ -type d ! -name . -prune -o -mtime +$NUM_DAYS -name '*.dat' )
        echo "$files2del"
for i in $files2del
                do
                        echo "Arg is ="
                done
)
done < dirlist_1.txt

Could you please advise how do I get the for loop correct.

11

You can just specify IFS for the read instead of changing it for the entire program:

while IFS=" " read -r dir; do
(
        cd $dir
        files2del=$(find ./ -type d ! -name . -prune -o -mtime +$NUM_DAYS -name '*.dat' )
        echo "$files2del"
for i in $files2del
                do
                        echo "Arg is ="
                done
)
done < dirlist_1.txt

This should let $files2del split on any whitespace.

12

But really, you shouldn't be putting an open-ended list like that into a variable. I don't think you need to cd either.

while IFS=" " read -r dir
do
        find "$dir" -type d ! -name . -prune -o -mtime +$NUM_DAYS -name '*.dat' | while read i
        do
                echo "got file $i"
        done
done < dirlist_1.txt
13

Or even just:

while IFS=" " read -r dir
do
        find "$dir" -type d ! -name . -prune -o -mtime +$NUM_DAYS -name '*.dat' -exec command_to_run_for_each_file '+'
done < dirlist_1.txt
1 Like
14

Its working perfectly now. Thanks to all !!!