- http://www.gnu.org/software/bash/manual/html_node/Filename-Expansion.html
- http://www.gnu.org/software/bash/manual/html_node/The-Shopt-Builtin.html
w/o this command line:
$ shopt -s nullglob
a glob pattern, that does not successfully evaluate to existing file names, gets literally resolved to a file name identical to the glob pattern.
With the above command line executed already, this command line will print file infos of /etc/passwd and ignore the unsuccessful other two glob patterns:
$ ll /etc/passwd /etc/passwd? /etc/passwd??
In interactive mode you may want to see the error messages, within a shell script supplying all three parameters to a “for f in …” loop, you will want the unresolving ones to get ignored.
$ for f in /etc/passwd /etc/passwd? /etc/passwd??; do echo $f; done
Well, at least in my script today I found this option rather useful.
I tried to find something comparable in the Korn Shell, but I wasn’t successful.
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