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# 1  
Old 09-21-2005
Finding last row
Using Linux and Bash, I have a script that outputs filenames with complete path, like this:
Quote:
/foo/bar/filename.pdf
/foo/bar/filename with space.pdf
/foo/filename.txt
I would like the following output:
Quote:
filename.pdf
filename with space.pdf
filename.txt
And I would like to get the filenames only. Tricky part is that I cannot predict how many levels deep the filename is located, so I cannot use standard Bash-kungfu to solve this...
Last edited by indo1144; 09-21-2005 at 10:20 AM..
# 2  
Old 09-21-2005
Add this line to the script

Code:
FILENAME=${file##*/}

where file would hold contain the values

Code:
/foo/bar/filename.pdf
/foo/bar/filename with space.pdf
/foo/filename.txt

one at a time.

And FILENAME would hold filename.pdf filename with space.. et al.

vino
# 3  
Old 09-21-2005
Quote:
Originally Posted by vino
Code:
FILENAME=${file##*/}

Now that worked perfectly!

I have no idea what this means, though. You set a new variable FILENAME that is $file with some magic applied. I do not understand the syntax and I am eager to learn more about this, since I find this very useful. Would you care to explain?
# 4  
Old 09-21-2005
Dare to start out with the man pages ? Smilie

Check out the section Parameter Expansion under man sh
and the section Parameters under man ksh

-vino
# 5  
Old 09-21-2005
Quote:
Originally Posted by vino
Dare to start out with the man pages ? Smilie

Check out the section Parameter Expansion under man sh
and the section Parameters under man ksh

-vino
Found it! I wanted to read more about this, but did not realize this was a shell built-in option, so did not think of man bash (in my case)...

Appreciate the help!
# 6  
Old 09-21-2005
Quote:
Originally Posted by indo1144
Found it! I wanted to read more about this, but did not realize this was a shell built-in option, so did not think of man bash (in my case)...
I believe I understand what happened...
Quote:
${parameter##word}
The word is expanded to produce a pattern just as in pathname expansion. If the pattern matches the
beginning of the value of parameter, then the result of the expansion is the expanded value of parameter
with the shortest matching pattern (the ``#'' case) or the longest matching pattern (the ``##'' case)
deleted. If parameter is @ or *, the pattern removal operation is applied to each positional parameter
in turn, and the expansion is the resultant list. If parameter is an array variable subscripted with @
or *, the pattern removal operation is applied to each member of the array in turn, and the expansion is
the resultant list.
So the ##-case expands to the longest matching pattern deletion. Since the parameter is *, it removes all matching patterns in the array, until it has no matches left. You read in the entire pathname as an array which has a delimiter "/" and the final result is the filename only.

Am I right?

This would mean that /foo/bar/filename.pdf would result in filename.pdf, but if the input would have a trailing slash like so: /foo/bar/files/ it would return... nothing!
# 7  
Old 09-21-2005
True.

At times {file##*/} can be use as an shell-builtin alternative for the command basename. But as you see, this scenario shows the difference between basename and {file##*/}

vino
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