# \[Ruby Newbie\] Reading in a file generated by df **URL:** \ **Category:** Ruby\ **Created:** [November 9, 2006, 11:02pm UTC](https://www.ruby-forum.com/t/ruby-newbie-reading-in-a-file-generated-by-df/75442 "2006-11-09T23:02:03Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![lmcilwain](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ac91a4/32.png) [@lmcilwain](https://www.ruby-forum.com/u/lmcilwain)\ **Post date:** [November 9, 2006, 11:02pm UTC](https://www.ruby-forum.com/t/ruby-newbie-reading-in-a-file-generated-by-df/75442/1 "2006-11-09T23:02:03Z")
Hello all, (yes its me again 🙂 ) I’m here at work and was hit with a very interesting problem. My boss would like for me to build a script that monitors disk usage on our database systems (OS X). I figured what better way to learn ruby then go right into a live situation. Granted, I’m not sure I’m ready for it but hell I will give it a shot anyway. So I don’t have a specific way to implement this so I figure I try something that I believe to be basic. 1. Generate a file (df -k \> filename.txt) 2. Read the file using Ruby code A. compare bites or percentage size (which ever is easier) with a set size that I determine. If the size read in exceeds the size that I have determined then it shoots a warning to me via e mail letting me know I need to deal with it. So, now that I have my idea out of my head an on paper, I started writing my code. require ‘yaml’ # Just in case I need it doc\_array = [] # Array to have each line read from the file put into a list file = File.new(‘diskcheck.txt’,‘r’) # Read the file while(line = file.gets) # Condition to put the files into the array doc\_array[doc\_array.length] = line end puts doc\_array # Test to see if file was read into array correctly So on to my problem (thanks for reading this far), When I try to get an ouput of the array that is supposed to have the several lines of the file read, it actually doesn’t come up with anything. I run my program and it just exits without any errors but there is also no output that comes to the screen… Do I need to convert this file or find a better way to read in this file? When I read in this file, It doesn’t spit out anything ---
**Author:** ![lmcilwain](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ac91a4/32.png) [@lmcilwain](https://www.ruby-forum.com/u/lmcilwain)\ **Post date:** [November 9, 2006, 11:46pm UTC](https://www.ruby-forum.com/t/ruby-newbie-reading-in-a-file-generated-by-df/75442/2 "2006-11-09T23:46:23Z")
I’d say your code is correct. I tried it myself, and it works. I use linux, though, but I don’t think this makes a difference. The only reason I can think of for what happens to you is that the file you’re trying to read is empty, but you’ll have already checked that. At any rate, there’s a far simpler way to read the contents of the file: doc\_array=File.readlines(‘diskcheck.txt’) I hope this can help ---
**Author:** ![lmcilwain](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ac91a4/32.png) [@lmcilwain](https://www.ruby-forum.com/u/lmcilwain)\ **Post date:** [November 10, 2006, 6:51am UTC](https://www.ruby-forum.com/t/ruby-newbie-reading-in-a-file-generated-by-df/75442/3 "2006-11-10T06:51:22Z")
> 1. Generate a file (df -k \> filename.txt) Your logic is correct, but if a human being is monitoring that disk space, it would be better to use df -kh so you get ``easily interpretable" values, the `h’ for human readable form. This is a well know fact, but i just thought i’d mention it anyway. 🙂 Regards, - vihan ---
**Author:** ![lmcilwain](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/ac91a4/32.png) [@lmcilwain](https://www.ruby-forum.com/u/lmcilwain)\ **Post date:** [November 10, 2006, 8:37am UTC](https://www.ruby-forum.com/t/ruby-newbie-reading-in-a-file-generated-by-df/75442/4 "2006-11-10T08:37:29Z")
Why create the file at all? disk\_check = `df -k` # shell out for the info directly disk\_check\_lines = disk\_check.split("/\n") # break it up disk\_check\_lines.each { test } #do your real test William