[SOLVED] script to delete selected files

colucix · 08-06-2010, 04:53 PM

Quote:

Originally Posted by tkmsr

I am having certain directories also with the same name how do I put it here on command line.

Sorry but this is not clear. Please can you rephrase?

Quote:

Also I forgot to ask the meaning of {} at the end of the command.

As grail said, the find command substitutes the {} symbol with the names of the files or directories found, one at a time, then executes the specified command. Take in mind that the command is executed multiple times, one for each item and that the escaped semi-colon is necessary to make find recognize the end of the command itself.

On the other hand, if you want to execute the command only once - for all the items together (as if they were passed as multiple arguments on the command line) you have to put a + sign in place of the escaped semi-colon, e.g.

Code:

$ find / -wholename /home -prune -o -name lighttpd -exec echo rm {} +
rm /usr/local/sbin/lighttpd /usr/src/lighttpd-1.4.26/src/lighttpd /usr/src/lighttpd-1.4.x/src/lighttpd /var/run/lighttpd /var/cache/lighttpd /var/log/lighttpd /var/lighttpd /etc/cron.daily/lighttpd /etc/logrotate.d/lighttpd /etc/init.d/lighttpd /etc/lighttpd

tkmsr · 08-06-2010, 10:25 PM

Quote:

Originally Posted by colucix

Sorry but this is not clear. Please can you rephrase?

Actually there are some files with name lighttpd and some other are directories as lighttpd-1.4 so I am finding only lighttpd

Quote:

Originally Posted by colucix

As grail said, the find command substitutes the {} symbol with the names of the files or directories found, one at a time,

I want to read more about it can you give some link.
I have read shell scripting tutorials many times but never came across such a usage.

Quote:

Originally Posted by colucix

On the other hand, if you want to execute the command only once - for all the items together (as if they were passed as multiple arguments on the command line) you have to put a + sign in place of the escaped semi-colon, e.g.

Great tip.I never knew such a thing so it increases some value to my learning experience.Thanks.

grail · 08-07-2010, 12:21 AM

Quote:

Actually there are some files with name lighttpd and some other are directories as lighttpd-1.4 so I am finding only lighttpd

This would mean now you need to do some globbing, eg.

Code:

find / -name "lighttpd*'

Quote:

I want to read more about it can you give some link.

Have you checked out 'man find'?

tkmsr · 08-07-2010, 12:47 AM

Yes man find I did.I mean to ask I need a link for the {} thin not the find command.

grail · 08-07-2010, 01:07 AM

Quote:

Yes man find I did.I mean to ask I need a link for the {} thin not the find command.

I got that you needed information on {} symbols and hence the link was to look in the man page.

When I searched in 'man find' I found the following:

Code:

-exec command ;
              Execute command; true if 0 status is returned.  All following arguments to find are taken to be arguments to the command until an argument consisting  of
              `;'  is encountered.  The string `{}' is replaced by the current file name being processed everywhere it occurs in the arguments to the command, not just
              in arguments where it is alone, as in some versions of find.  Both of these constructions might need to be escaped (with a `\') or quoted to protect them
              from  expansion  by the shell.  See the EXAMPLES section for examples of the use of the -exec option.  The specified command is run once for each matched
              file.  The command is executed in the starting directory.   There are unavoidable security problems surrounding use of the -exec action; you  should  use
              the -execdir option instead.

tkmsr · 08-07-2010, 01:41 AM

Quote:

Originally Posted by grail

-exec command ;

Thanks for pointing this
when I did man find in the bottom left most corner as search string I had typed

Code:

/{

to which it gave a message as

Code:

Invalid pattern  (press RETURN)

It is in exec this was not known to me.
Thanks.

colucix · 08-07-2010, 02:43 AM

You may also check the online GNU findutils manual. The browser search function can be very useful if you read from the second link (HTML entirely on one web page).

colucix · 08-07-2010, 02:46 AM

Quote:

Originally Posted by tkmsr

Code:

/{

to which it gave a message as

Code:

Invalid pattern  (press RETURN)

When searching in man pages some characters need to be escaped:

Code:

/\{\}

grail · 08-07-2010, 03:01 AM

Quote:

It is in exec this was not known to me.

Sorry ... my bad ... made the assumption that you knew that went together

I had the same search issue, but I cheated a little and just searched for the closing brace, so /} works

tkmsr · 08-07-2010, 05:15 AM

Ha ha no problem.But I am really curious to know as coculix mentioned /\{
so which character in man page we need to precede with \

Those html links are interesting I never came across any such thing.

grail · 08-07-2010, 06:14 AM

\ is the universal escape character in many things *nixish. Therefore \\ is the escape for \ to be searched for

tkmsr · 08-07-2010, 07:06 AM

:) Well this I know.
Let me explain again
I searched in man page as

Code:

/{

and not

Code:

/\{

where as you searched

Code:

/}

and not

Code:

/\}

.
To get my result I need to type in

Code:

/\{

and where as you got it
only by

Code:

/}

.

So you should also have got result by search

Code:

/\}

and not

Code:

/}

.

grail · 08-07-2010, 08:56 AM

ahhh ... with you now. The opening curly brace has special significance and so needs to be escaped. However, The closing curly brace is only
important if the opening one has been used, so the following is how it works:

Code:

/\{ - - for only the opening brace

/{ - -for only the closing brace

/\{\} - - for both the opening and closing

Hope that helps

tkmsr · 08-07-2010, 09:11 AM

Yea that did help but why is the opening curly brace so important ?
This thing I am curious to know.

grail · 08-07-2010, 10:33 AM

Have a search on this page for the braces and see what they are intended for.