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Re: Pattern extraction and Wildcard expansion
> I have the function:
>
> nl = {
> }
> fn s pat {
> lis = `{for (dir = $path) ls $dir}
> a = <={~~ $lis $pat}
> echo $a^$nl
> }
>
> and try to execute:
>
> ; s l*
>
> Mi intention is to get a list of commands that begin with "l", but
> there is no output.
>
> Where is my error?
Quoting. ~ and ~~ are special with regard to quoting. The pattern
argument to ~ and ~~, if it includes wildcards, must be an unquoted
literal. Eval might be helpful here, but introduces at least as many
problems as it solves.
I tend to do that sort of thing with ``here's the prefix I'm interested
in'' explicitly, though you can make eval work properly, with care.
There are a couple of other problems. The l* argument to s will be
expanded against the list of files in the current directory before s is
called, so you're matching againt the wrong thing; if l* doesn't match
anything in the current directory, you'll get the equivalent of 'l*'.
--p
Here's a crude toy, based on the thing you were writing:
fn commands-starting-with prefixes {
for (dir = $path) {
for (file = $dir/$prefixes^*) {
if { access -x $file } {
echo $file
}
}
}
}
; commands-starting-with ghost java
/home/jdk/bin/java
/home/jdk/bin/java-rmi.cgi
/home/jdk/bin/javac
/home/jdk/bin/javadoc
/home/jdk/bin/javah
/home/jdk/bin/javap
/usr/bin/ghostscript
/usr/bin/X11/ghostview
/usr/X11R6/bin/ghostview
;
I think it should be reasonable to do something like:
commands-matching '*view'
by using eval, but that's left as an exercise for the reader.
--p