Shell Programming and Scripting

Hello, I am very new to shell scripting. This problem seems quite easy so it should be quite easy (I hope ^^)
I want to get a random file from a directory. this file will be in one subdirectory, and it will contain spaces.

code I have got so far:

N=find ./*/*.jpg | wc -l
((N=RANDOM%N))

That gives me a number. Now I want to select the Nth file in this file list generated by find ./*/*.jpg

I wanted to use echo ./*/*.jpg except that gave me spaces as a delimiter, which is kind of stupid ^^, since file names contain spaces

***code removed***

Please see the rules, no classroom/homework posts allowed.

I have reopend this thread becasue the member gave a satisfactory justification for the thread by PM.

Sorry David, seems I was a bit hasty. For future reference if you explain what you are trying to achieve it might avoid this, in particular since you are posting from an educational domain.

ksh code:

Code:

set +A files ./*/*.jpg    # create an array of the files.
N=${#files[@]}           # Number of members in the array
((N=RANDOM%N))
randomfile=${files[$N]}

bash:

Code:

files=(./*/*.jpg)        # create an array of the files.
N=${#files[@]}          # Number of members in the array
((N=RANDOM%N))
randomfile=${files[$N]}

ksh arrays are small. Only 1024 is guaranteed. bash does not seem to have an arbritrary limit.

My version of ksh (1993-12-28 q) doesn't seem to have a limit either. I did a test to assign values to a array in a loop. I gave up at 700,000 elements.

ksh seems to be twice as fast than bash to assign array values. So, I pushed my little benchmark a little bit further and I assigned 10,000 values to an array and randomly accessed that array 1000 times.

Code:

bash
  real    0m0.623s
  user    0m0.500s
  sys     0m0.020s

ksh
  real    0m0.157s
  user    0m0.160s
  sys     0m0.000s

Happy new year to all.

I looked it up in Korn's book: "The subscript for an indexed array can be any arithmetic expression that evaluates between 0 and some implementation-defined value that is at least 4095.

And the O'reilly bash book says: "up to 599147937791" (Of course, you will probably run out of virtual memory before that.)

Also ksh is faster than bash for anything that loops because ksh compiles the loop. bash re-interprets the loop each iteration.

THanks guys! I hope my wallpaper will now change every 1 hour ^_^