Help!! Shell script to get output of ls -l command into an array

kasthana · 05-28-2008, 04:08 PM

Hi

I have a requirement to get the output of ls-l command into an array.

Suppose there are three files in directory and the output is as :

-rw-r----- 1 kas kas 53 May 28 20:44 t1.dat
-rw-r----- 1 kas kas 53 May 28 20:44 t2.dat
-rw-r----- 1 kas kas 124 May 28 20:44 t3.dat

I want each line of output to be stored as seperate element of an array; as

arr[0] -rw-r----- 1 kas kas 53 May 28 20:44 t1.dat
arr[1] -rw-r----- 1 kas kas 53 May 28 20:44 t2.dat
arr[2] -rw-r----- 1 kas kas 124 May 28 20:44 t3.dat

Thanks

jim mcnamara · 05-28-2008, 04:27 PM

Code:

let cnt=0
ls -l | \
while read line
do
    echo $cnt
	arr[$cnt]="$line"
	cnt=$(( $cnt + 1 ))
done
echo "$cnt lines read"

kasthana · 05-28-2008, 05:02 PM

Thanks for response.
I tried to execute the following code and the output is as:
0
1
2
3
0 lines read

It seems array is not filled up and also cnt value becomes zero after done statement.

Could you please help me with the reason.

Thanks

chrism01 · 05-28-2008, 06:01 PM

The pipe opens a subprocess, so any info created there is not avail to the parent process
http://tldp.org/LDP/Bash-Beginners-G...tml/index.html
http://www.tldp.org/LDP/abs/html/

This wouldn't be homework/coursework by any chance?
http://catb.org/~esr/faqs/smart-questions.html

osor · 05-28-2008, 07:03 PM

Here is what I would do:

Code:

IFS='
' read -d '' -a arr < <(ls -l)

Since we are using bash after all, we can use the <() construct.

kasthana · 05-29-2008, 10:59 AM

Thx all, I am able to solve the problem

osor · 05-29-2008, 01:31 PM

Btw, if you want to use pipes, you can do so as well, as long as you use your array inside the subshell. For example,

Code:

ls -l | (

    IFS='
'   read -d '' -a arr

# Do all accessing and processing of arr here

) # arr goes out of scope here

osor · 06-01-2008, 10:21 PM

There was a much simpler way (and I have edited my post accordingly).

ghostdog74 · 06-01-2008, 11:37 PM

what do you actually need to do to those ls -l output lines?? why not do your line processing "on the spot"

Code:

ls -l | while read blah
do
 # process lines.
done