1. CIT 383: Administrative Scripting
Find
CIT 383: Administrative Scripting

2. CIT 383: Administrative Scripting
The find command
Searches for files in a directory tree
find path operators
Can search for files based on
-name
-perm
-size
-type
-user
-group
-atime, -mtime, -ctime
CIT 383: Administrative Scripting

3. CIT 383: Administrative Scripting
Find times
Numbers refer to 24-hour periods
Find files modified during the 24-hour period that ended exactly 3 days ago, i.e. the time between 72 and 96 hours ago.
find / -type f –mtime 3
- refers to times after the 24-hour period
Find all files modified between now and 3 days ago.
find / -type f –mtime -3
+ refers to times before the 24-hour period
Find all files not accessed in last 30 days
find / -type f –atime +30
CIT 383: Administrative Scripting

4. CIT 383: Administrative Scripting
Fast find commands
The locate command searches index for files
locate filename
Faster than find, but
Can only search based on name.
Will miss files not in index.
Must update index regularly with updatedb.
CIT 383: Administrative Scripting

5. Manipulating files with find
Find can exec a command on each file
find . –name “*.bak” –exec rm –f {} \;
find /var/logs –mtime +7 –exec rm –f {} \;
find / –user jsmith –exec chown root {} \;
To operate on all at once, pipe to xargs
find /var/logs –mtime +7 | xargs grep failure
find / -user jsmith | xargs file
CIT 383: Administrative Scripting

6. CIT 383: Administrative Scripting
Find.find
Execute block for all files under path
Find.find(topdir) do |path|
... process path ...
end
Use prune inside block to ignore directories.
CIT 383: Administrative Scripting

7. CIT 383: Administrative Scripting
Finding Files by Name
Match whole name
if path == “core”
Match using substrings.
if path[-4,4] == “.xls”
Match using regular expressions.
if path =~ /\.(xls|doc|ppt)$/
CIT 383: Administrative Scripting

8. Finding Files by Other Criteria
Obtain a File::Stat object
Find.find(topdir) do |path|
stat = File::Stat.new(path)
... process based on stat ...
end
Match by size
if stat.size > 1_000_000
Match by owner
if stat.uid == Process.uid
CIT 383: Administrative Scripting

9. Storing found filenames in an Array
matching_files = Array.new
Find.find(topdir) do |path|
if condition
matching_files << path
end
CIT 383: Administrative Scripting

10. Storing file metadata in a Hash
filedata = Hash.new
Find.find(topdir) do |path|
stat = File::Stat.new(path)
if condition
filedata[path] = stat.method
end
CIT 383: Administrative Scripting

11. Storing file data in a Hash
filedata = Hash.new
Find.find(topdir) do |path|
File.open(path) do |fh|
if condition
filedata[path] = fh.read
end
CIT 383: Administrative Scripting

12. CIT 383: Administrative Scripting
References
Michael Fitzgerald, Learning Ruby, O’Reilly, 2008.
David Flanagan and Yukihiro Matsumoto, The Ruby Programming Language, O’Reilly, 2008.
Hal Fulton, The Ruby Way, 2nd edition, Addison-Wesley, 2007.
Dave Thomas with Chad Fowler and Andy Hunt, Programming Ruby, 2nd edition, Pragmatic Programmers, 2005.
CIT 383: Administrative Scripting