[plug] Simple bash scripting problem (again)

[Richard Meyer]

On Mon, 2005-10-10 at 20:56 +0800, Craig Ringer wrote:
> Richard Meyer wrote:
> 
> >On Mon, 2005-10-10 at 19:28 +0800, Timothy White wrote:
> >
> >I've found out that the following find command does it
> >
> >richard1 at Selous:~/project> cat test.sh
> >#!/bin/bash
> >        find . -name "$@" -print
> >  
> >
> That'll work, but probably not how you expect. Consider:
> 
> $ ./test.sh "a b c"
> 
> That'll find a file named "a b c" in any subdirectory, and print the 
> path to it. 

True - I think -depth will be our friend here ... ;-)  - good spot,
there

> However, you'll get a pretty odd result if you call it as:
> 
> $ ./test.sh "a b c" d
> 
> ... since your `find' command expands to:
> 
> find . -name "a b c" d -print
> 
> If you want the effect of:
> 
> find . -name "a b c" -print -o -name d -print
> 
> then you need to go about it another way. The script you posted makes no 
> sense with more than one argument unless you want to do something awful 
> like call it as:
> 
> $ ./test.sh "a b c" -print -o -name
> 
> so it should only accept one argument, eg:
> 
> if (( $# != 1 )); then
>    echo "Usage: `basename $0` nametofind"
>    exit 1
> fi
> find . -name "$1" -print

Yes, I was assuming that it took only one parameter, and I really wasn't
there to write the whole script ... I had to leave something for the
student to do (ie all the dull stuff)   ;-)
> 
> or it should properly handle multiple names.
> 
> >If I may make a suggestion, try reading find with the "-exec" option and
> >see whether you can get it to do what you want
> >  
> >
> For efficiency it can often be better to use:
> 
> find .... -print0 | xargs -0 command
> 
> where `command' takes a list of one or more files to operate on, as 
> generally output by find. The -print0 and -0 use NULLs to separate the 
> filenames instead of newlines, which helps if you have some very strange 
> filenames to deal with.
> 
> In this case, though, a shell script looks like the ideal way to tackle 
> what he seems to be doing - it's just a matter of navigating a few 
> pitfalls first.
> 
Agreed, and I was trying to solve the problem he stated up front - 

I think we're more in agreement than otherwise ... thanks for the crit -
some good points.
> --
> Craig Ringer
> _______________________________________________
> PLUG discussion list: plug at plug.org.au
> http://www.plug.org.au/mailman/listinfo/plug
> Committee e-mail: committee at plug.linux.org.au
-- 
Richard Meyer <meyerri at westnet.com.au>
Cutting the space budget really restores my faith in humanity.  It
eliminates dreams, goals, and ideals and lets us get straight to the
business of hate, debauchery, and self-annihilation.
                -- Johnny Hart

Linux Counter user #306629