Grep for regex in basename but return wholename

Question

So say I have a list of files in a text file:

...
/foo/barfoo
/bar/foo/foobar
/foobar/bar/foo
...

I have a script that will search through this text file and, much like the locate command, I want to be able to search for the basename of the file. Thus far I've used this grep command grep -E */.*${1}[^/]*$ which works fine UNLESS I want to grep for a regex. So, in the above example if I wanted to find files starting with "foo", I'd execute myscript --basename ^foo however this fails because the whole regex becomes grep -E */.*^foo[^/]*$ which would, obviously, fail. I thought about using xargs to plug each entry into basename but I need the script to put out the whole file path at the end.

Any ideas? I'd prefer POSIX compliance but GNUisms are fine too

Answer 1

If foo must match at the start of the basename:

< inputfile grep '/foo[^/]*$'

• /foo[^/]*$: matches a /foo string followed by any number of any character not / at the end of the string

if foo can match anywhere in the basename:

< inputfile grep 'foo[^/]*$'

• foo[^/]*$: matches a foo string followed by any number of any character not / at the end of the string

Answer 2

If your grep supports PCRE (Perl-compatible regular expressions) :

$ grep -Po '.*/\Kfoo[^/]*$' file.txt 
foobar
foo

• .*/ will match upto the last / and \K will discard the match

• foo[^/]*$ will find the filenames starting with foo