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FromFPan2Fire 01-04-2007 03:05 AM

ls with recursive option and file name doesn't work
 
I am having a very basic problem with the ls command.

Version: Ubuntu; 6.06 LTS (Dapper D)

Entering ls command from a terminal window:

When I do "ls -R" I get what I expect, a recursive list of all files

When I do "ls a*" I also get what I expect - list of files starting with "a" in the current directory

But when I combine them: "ls -R a*" looking for a list of all files starting with a in the current directory and all subdirectories, it appears to ignore the "-R" option, only returning results from the current directory.

For another example, I know I have files in a subdirectory beginning with W; But when I do "ls -R W* " it says No Such File or Directory; If I do ls -R then I can see files starting with W.

What is it that I'm not getting? :scratch:

Thank You

timmeke 01-04-2007 04:06 AM

Quote:

Originally Posted by FromFPan2Fire
For another example, I know I have files in a subdirectory beginning with W; But when I do "ls -R W* " it says No Such File or Directory; If I do ls -R then I can see files starting with W.

Actually, it's the shell (ie Bash) that expands the "W*" to the names of all files/directories in the current
directory that start with "W", prior to passing the expansion result to "ls".

So, let's say I have, in my current directory:
W1.txt
W2.txt
W3 - a subdirectory
Than, "ls W*", will actually be performed as "ls W1.txt W2.txt W3" ("ls" gets 3 input parameters, not just the 'W*').

Following this idea, then you can't locate files with names starting with W in all subdirectories by
simply calling
Code:

ls -R W*
As this is performed as follows:
1. The shell expands "W*" to all names of files/directories IN THE CURRENT DIRECTORY that have names starting with "W". If there aren't any, you'll get "No such file or directory".
2. If the shell did find some files/directories with W, it'll pass them all to "ls" as input parameters.
3. "ls -R" is performed for each of the parameters "ls" gets from the shell (if there are any).

To find all files starting with W in a recursive way (ie in the current directory and all subdirectories), you
need to use "find", not "ls". Example:
Code:

find . -name 'W*'
You may add "-type f" option to find to restrict the output to regular files (ie no directories, symbolic links, fifo pipes, device files, etc).
"-maxdepth n" restricts the number of recursively searched levels to "n".

For more details on "find" and "ls", please read their respective man pages.

FromFPan2Fire 01-04-2007 05:05 AM

ls and find command clarified
 
Thank You
I appreciate your assistance.
That's what I was looking for.

timmeke 01-04-2007 06:07 AM

You're welcome.

scm2 08-15-2009 10:07 AM

thanks, that's just what I was trying to do as well!

But I also have another similar question as well...

How do I grep, but only in a certain file type?

For example, if I try this I get thousands of results (it's a small common word in a very big directory structure)

grep 'common word' * -R

so I want to be able to do something like this:

grep 'common word' *.csv -R

But this doesn't work, probably for the same reasons as above. So is there a way to do this?

salasi 08-16-2009 06:10 AM

OK, just this once....

You shouldn't do this
  • its probably 'necroposting'
  • the new question isn't sufficiently closely related to the original to be a minor clarification

so better to start a new thread.

But as you have dragged me into your necropost to even tell you this, I might as well give you my contribution.

timmeke's explanation and way of deasling with the original question was the more elegant, more classy, way of dealing with it, but a 'brute force and ignorance' person like myself could also consider:

ls -R | grep filename

(where filename is, well the filename, or file name fragment of interest, and if you want to ignore case, then that would be grep -i rather than grep (see 'man grep' ))

This then leads on to the possibility of using grep several times. I'll generalise the problem a little bit and asume that you are looking for all files that are variants of squid confinfiguartion files anywhere on your system (and that you have locate/slocate/... installed and that the database is updated...you can do this manually with updatedb but your distro probably schedules this while you are asleep)

locate squid | grep -i conf

will catch all files that contain the substrings 'squid' and 'conf' (or CONF or Conf or config...) and if you want to only see the ones that also contain .bak, or some variation thereof (replace .bak with .old or whatever you use, if you are adding extensions to old files manually)

locate squid | grep -i conf | grep -i .bak

or all files in the user1 tree with ~ in the title (which are almost certainly the automatic backup files made by a text editor when user1 edits files)

locate user1 | grep ~

HTH (and don't do it again, as I don't want the mods on my tail :redface: )

chrism01 08-16-2009 08:16 PM

Might as well continue by pointing out grep has many switches/options, inc -r (-R) = recursive
http://linux.die.net/man/1/grep
;)

roberthallphoto 01-05-2010 11:21 AM

Thank you all for your answers.


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