Tuesday, November 5, 2013

the bash's "nullglob" is rather nice to use


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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