Bash – ls command: how to ignore case without globbing

bashlswildcards

I use the shopt -s nocaseglob command to ignore case, but it seems like it doesn't work if I use a string without glob.

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Just a question out of curiosity, is it possible to ignore case without globbing?
i.e. ls a would output both a and A

Best Answer

Not with ls no. You could, however, use something like these:

$ ls [Aa]
$ find . -iname a
$ echo [aA]

The reason behind this is that the shopt command only affects how globs are expanded by the shell. So, when you run ls *a after running the shopt command, that gets expanded by your shell to

ls a A

So, as @Kevin said, the glob is expanded before being passed to ls, therefore the nocaseglob will have no effect when you give a simple string and not a glob.

Related Solutions

Shell – shopt -s nocaseglob is not working on Ubuntu

Are you really doing globbing, i.e. wildcard expansion? For example, suppose that you have a directory called Foobar. Then

cd foobar

doesn't do globbing, because there is no wildcard character. When you specify a file name exactly, it's up to the application to decide what to do with it, and since unix file names are case sensitive, the application will not open a file called Foobar if you tell it to open a file called foobar.

On the other hand,

cd foo*

will change to the Foobar directory (assuming there is no other match), if you've set the nocaseglob option.

You can make completion case-insensitive too. Put set completion-ignore-case on in ~/.inputrc, or

bind 'set completion-ignore-case on'

in ~/.bashrc. Then after entering cd foo and pressing Tab, the shell will complete Foobar.

Bash globbing of multi-part argument

The -false idea is the key, IMHO. I'm just adding to it:

find . -false $(echo "-o -name *."{sh,pl,sql})

You just quote everything to make bash repeat the whole pattern, including -o -name, and then "break" the grouping made by the quoting by returning it from a subshell. The problem with this approach is that quotes in the pattern won't work.

EDIT: See Michał Šrajer's comment for another pitfall of this solution. Note that you can't just put a backslash before the star: the command substitution returns either a *, which will get expanded, or a \*, which will get passed as-is to find (!). At least, that's how my local bash works.

This is the best I can do:

 (GLOBIGNORE='*:.*'; find . \( -false $(echo "-o -name *."{sh,pl,sql,xml}) \) -print)

Good luck :)

Btw, if you are not going to add more parameters to find, of course just use xargs; in that case it works perfectly, with quotes and everything:

echo "-o -name *."{sh,pl,sql} | xargs find . -false

Best Answer

Related Solutions

Shell – shopt -s nocaseglob is not working on Ubuntu

Bash globbing of multi-part argument

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