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Re: Question about wildcards in Unix

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In article <1lfruh8.1ni6lfs1qgbzg2N%dempson@actrix.gen.nz>, David
Empson <dempson@actrix.gen.nz> wrote:

> JF Mezei <jfmezei.spamnot@vaxination.ca> wrote:
> 
> > On 14-01-19 17:46, Joanna Shuttleworth wrote:
> > >
> > >> ls -R *.c only lists .c files in the current directory
> > >> ls -R */*.c will list .c files in any subdirectory
> > 
> > > no, but the first command would recursively list the entire contents
> > > of any directory with a name ending in '.c'.
> > 
> > That is the problem. It doesn't do that. It only lists .c files present
> > in the current directory and does not go into subdirectories to look for
> > other .c files.
> 
> Read what nospam said again.

it wasn't me. i haven't been a part of this thread (until now).

> If the current directory contains a subdirectory which has a name ending
> in ".c", then "ls -R *.c" will recursiely list the entire contents of
> that subdirectory (and any other similarly named subdirectories in the
> current directory).
> 
> It will also list any files in the current directory which have names
> ending in .c.
> 
> This is because the "*.c" wildcard in "ls -R *.c" is expanded by the
> shell, replacing it with the name of all files and subdirectories in the
> current directory, before the whole command is passed to ls.
> 
> For example, if the current directory contained files a.c and b.c, and a
> subdirectory called more.c, then "ls -R *.c" would be expanded by the
> shell to "ls -R a.c b.c more.c". The ls command would list the files a.c
> and b.c, then the entire contents (recursively) of the more.c
> subdirectory (all files in that subdirectory would be listed, not just
> filenames ending in ".c").
> 
> As Siri Cruz said, the "find" tool is a better way to do what you want:
> 
> find . -name '*.c' -print
> 
> This will list all files in the current directory and recursively in all
> subdirectories which have a name matching the pattern '*.c'.
> 
> In this case, the '*.c' is not expanded by the shell because of the
> single quotes. It gets passed to the find command, which uses it as a
> pattern to match.
> 
> 
> The second command you used (ls -R */*.c) is also not doing quite what
> you think it is doing.
> 
> In this case, the shell will expand */*.c to all files with names ending
> in ".c" which are in all first level subdirectories of the current
> directory, then pass them to ls, which will list them. It won't list any
> ".c" files in the current directory, nor in any second level (or deeper)
> subdirectories.
> 
> The -R option only comes into play if any of the files in the first
> level subdirectories happen to be a subdirectory with a name ending in
> ".c", in which case ls will also list the entire content of that
> subdirectory recursively.

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Thread

Question about wildcards in Unix JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-19 17:19 -0500
  Re: Question about wildcards in Unix Siri Cruz <chine.bleu@yahoo.com> - 2014-01-19 14:42 -0800
  Re: Question about wildcards in Unix Joanna Shuttleworth <js@example.com> - 2014-01-19 22:46 +0000
    Re: Question about wildcards in Unix JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-19 18:16 -0500
      Re: Question about wildcards in Unix dempson@actrix.gen.nz (David Empson) - 2014-01-20 12:43 +1300
        Re: Question about wildcards in Unix nospam <nospam@nospam.invalid> - 2014-01-19 19:02 -0500
          Re: Question about wildcards in Unix dempson@actrix.gen.nz (David Empson) - 2014-01-20 17:41 +1300
        Re: Question about wildcards in Unix JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-19 19:55 -0500
          Re: Question about wildcards in Unix Jolly Roger <jollyroger@pobox.com> - 2014-01-20 03:00 +0000
          Re: Question about wildcards in Unix mcarels@xs4all.nl (Maarten Carels) - 2014-01-20 10:05 +0100
            Re: Question about wildcards in Unix Tim Streater <timstreater@greenbee.net> - 2014-01-20 09:49 +0000
              Re: Question about wildcards in Unix Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-20 12:57 -0800
                Re: Question about wildcards in Unix JF Mezei <jfmezei.spamnot@vaxination.ca> - 2014-01-20 16:15 -0500
                Re: Question about wildcards in Unix Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-20 14:10 -0800
                Re: Question about wildcards in Unix Tim Streater <timstreater@greenbee.net> - 2014-01-20 23:06 +0000
                Re: Question about wildcards in Unix Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-20 16:39 -0800
                Re: Question about wildcards in Unix nospam <nospam@nospam.invalid> - 2014-01-20 18:44 -0500
                Re: Question about wildcards in Unix Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-20 16:42 -0800
                Re: Question about wildcards in Unix Tim Streater <timstreater@greenbee.net> - 2014-01-21 10:23 +0000
            Re: Question about wildcards in Unix Jolly Roger <jollyroger@pobox.com> - 2014-01-20 18:43 +0000
      Re: Question about wildcards in Unix Doug Anderson <ethelthelogremovethis@gmail.com> - 2014-01-20 12:55 -0800

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