ls only files starting with upper case character

sancho1980 · 05-14-2006, 10:50 AM

does anyone know how to use ls so that it only returns those files which start w/ an uppercase character?
thanx,
martin

haertig · 05-14-2006, 11:11 AM

Code:

ls | grep "^[A-Z]"

Disillusionist · 05-14-2006, 11:22 AM

To display only files and directories that begin with an uppercase character:

Code:

ls |grep '^[ABCDEFGHIJKLMNOPQRSTUVWXYZ]

Disillusionist · 05-14-2006, 11:24 AM

Sorry, forgot to close the quote.

ioerror · 05-14-2006, 11:34 AM

There's no need to use grep, the shell can handle this simple pattern matching:

Code:

ls [A-Z]*

That will dispaly only uppercase ASCII characters of course.

Code:

ls [[:upper:]]*

With this, what qualifies as an "uppercase" character will be locale dependent .

However, if you have a _lot_ of files, this could result in a 'command line too long' error, in which case you can use the grep suggestion above (or find, etc).

Also note that you'll get an error if there are no matching files, unless you set the nullglob shell option.

sancho1980 · 05-14-2006, 01:13 PM

thanx for all ur replies

sancho1980 · 05-14-2006, 05:02 PM

[:upper:]

By the way, what is upper? Is that a system variable? And why the two colons?

ioerror · 05-14-2006, 06:06 PM

It is a regular expression pattern called a "character class", and has the form '[:class:]'. It is always specified inside the character matching metacharacters [].

There are a number of "classes", alpha (any alphabetic character in the current locale), upper, lower, digit and so on. You can find the full list of classes in the bash man page (searching for 'alnum' will take you straight there) or any text on regular expressions (the grep man page has a short introduction to regex).

sancho1980 · 05-14-2006, 06:32 PM

ah, thanx
i was playing around a little with the bash pipe functionality and now i'm starting to wonder:

if

ls | grep ^[[:upper:]]

gives me all files starting with an uppercase character then why does the following NOT work:

ls | grep ^[[:upper:]] | cp /directory

..meaning to copy all these files into /directory

martin

cs-cam · 05-14-2006, 07:52 PM

You could use find to do the whole thing:

Code:

find . -maxdepth 1 -type f -name '[[:upper:]]*' -exec cp {} /directory \;

ioerror · 05-15-2006, 04:23 AM

It doesn't work because cp doesn't read from stdin by default, so there a special option to indicate that it should do so, namely --target-directory=...

Agrouf · 05-15-2006, 06:26 AM

command1 | command 2 uses standard output of command1 as standard input for command2. Arguments are different from standard input. grep parses the standard input and put the result in the standard output. cp doesn't read standard input by default, but uses arguments instead.
Anway, the simplest way is :

cp [[:upper:]]* /directory

or, if the argument list is too long,

for filelist in $(ls | grep ^[[:upper:]])
do
cp $filelist /directory
done

haertig · 05-15-2006, 10:30 AM

Quote:

Originally Posted by ioerror

Code:

ls [A-Z]*

One would think this would work, but it doesn't. At least not on Debian Sarge and Sid. I would call this a bug myself. Funny thing, it doesn't work, but it doesn't work in a different manner than I can explain (see it filter aa below, but not bb or cc!!!)

Code:

$ mkdir tmp
$ cd tmp
$ >aa
$ >Aa
$ >bb
$ >Bb
$ >cc
$ >Cc
$ ls [A-Z]*
Aa  bb  Bb  cc  Cc
$ ls
aa  Aa  bb  Bb  cc  Cc
$

Perplexed, I tried this same test on Debian Sid. Same results. Next test, ... on to Solaris.

Solaris got it right:

Code:

$ mkdir tmp
$ cd tmp
$ >aa
$ >Aa
$ >bb
$ >Bb
$ >cc
$ >Cc
$ ls [A-Z]*
Aa  Bb  Cc
$ ls
Aa  Bb  Cc  aa  bb  cc
$

Agrouf · 05-15-2006, 11:04 AM

Quote:

Originally Posted by haertig

One would think this would work, but it doesn't. At least not on Debian Sarge and Sid. I would call this a bug myself. Funny thing, it doesn't work, but it doesn't work in a different manner than I can explain (see it filter aa below, but not bb or cc!!!)

Code:

$ mkdir tmp
$ cd tmp
$ >aa
$ >Aa
$ >bb
$ >Bb
$ >cc
$ >Cc
$ ls [A-Z]*
Aa  bb  Bb  cc  Cc
$ ls
aa  Aa  bb  Bb  cc  Cc
$

Perplexed, I tried this same test on Debian Sid. Same results. Next test, ... on to Solaris.

Solaris got it right:

Code:

$ mkdir tmp
$ cd tmp
$ >aa
$ >Aa
$ >bb
$ >Bb
$ >cc
$ >Cc
$ ls [A-Z]*
Aa  Bb  Cc
$ ls
Aa  Bb  Cc  aa  bb  cc
$

Are you sure you don't have an ls alias messing that up?

haertig · 05-15-2006, 11:15 AM

Quote:

Originally Posted by Agrouf

Are you sure you don't have an ls alias messing that up?

I don't believe so. I am old school and don't like the fancy colors ls can do, so I had commented out all aliases in .bashrc (originally it had alias ls='ls --color=auto', but I wiped that out long ago). Calling /bin/ls directly does same thing:

Code:

$ /bin/ls [A-Z]*
Aa  bb  Bb  cc  Cc
$

Good thought though. After you said this, I went and verified that I didn't have any aliases getting in the way. Just to be sure.