Martin Gregorie wrote:
> On Sat, 2011-08-27 at 14:32 -0500, jorl17 wrote:
>
> > locate is another utility similar to find but that uses indexing
> > (someone correct me if that's wrong) to make it work faster
> >
> >
> 'locate' is fast because it searches a database of all the filenames in
> the system. The database is rebuilt on a daily basis when the cron
> daemon runs 'updatedb' via the mlocate.cron script [1], so it can can be
> up to 24 hours out of date. The command 'locate text' will list all the
> files or directories that have 'text' anywhere in their absolute
> pathname, i.e. if you wanted to find a file called recipes_etc and
> entered the command 'locate etc', locate would list it if it existed
> when updatedb was last run but would also list the several hundred files
> in the /etc directory structure. 'locate' is very fast because all the
> text it searches is gathered into one place but you have to be aware
> that its never fully up to date, that it is matching on absolute path
> names and that it always looks at every filename anywhere in your
> system.
>
> 'find', on the other hand, is a lot slower because it has to read
> through all the directories its been asked to search but is always
> up-to-date because it is looking directly at the filing system. It has
> fewer gotchas because of this. It can also search just a selected part
> of the filing system. e.g. if you are on your $HOME directory, running
>
> find . -name '*etc*'
>
> will only search the current directory ('.') and all the directories
> within it. Specifying the search text as '*etc*' is necessary to find
> files containing 'etc'. If you just asked for 'find . -name etc' it
> would only find files and directories whose name is 'etc' and only
> 'etc'. If you put globs (* matches zero or more characters) or question
> marks (? matches a single character in that position) in the search
> pattern you should enclose them in single quotes to prevent the shell
> from expanding them.
>
> Find is extremely versatile: it understands and can use file creation
> time or last access time as search terms and can also run commands
> against matching files:
>
> find . -name '*.bak' -exec rm {} \;
>
> will delete all files with a .bak extension in the current directories
> and those inside it. {} is replaced with the matching file name when the
> command (rm) is run and ; ends the command to be run: it has to be
> escaped as shown so it will be included as the end of the -exec command
> rather that the shell taking it as the end of the 'find' command.
>
> [1] cron normally runs the jobs in /etc/cron.daily around 3AM but, if
> the computer isn't running then, it will remember that some jobs haven't
> been run when its next started and will run them some time on the next
> hour or two.
>
> Martin
Exactly, thanks. That's pretty much what I meant with "indexing", though it was not the right term at all.
The point is that OP has to understand how all these tools work and how his/her OS is built. These commands that we've all learned to use are pretty much gibberish talk to OP. Thanks Martin, that was a really good explanation for OP!
