How to split path by last slash?

Question

I have a file (say called list.txt) that contains relative paths to files, one path per line, i.e. something like this:

foo/bar/file1 foo/bar/baz/file2 goo/file3 

I need to write a bash script that processes one path at a time, splits it at the last slash and then launches another process feeding it the two pieces of the path as arguments. So far I have only the looping part:

for p in `cat list.txt` do    # split $p like "foo/bar/file1" into "foo/bar/" as part1 and "file1" as part2    inner_process.sh $part1 $part2 done 

How do I split? Will this work in the degenerate case where the path has no slashes?

Answer 1

Use basename and dirname, that's all you need.

part1=$(dirname "$p") part2=$(basename "$p") 

Answer 2

A proper 100% bash way and which is safe regarding filenames that have spaces or funny symbols (provided inner_process.sh handles them correctly, but that's another story):

while read -r p; do     [[ "$p" == */* ]] || p="./$p"     inner_process.sh "${p%/*}" "${p##*/}" done < list.txt 

and it doesn't fork dirname and basename (in subshells) for each file.

The line [[ "$p" == */* ]] || p="./$p" is here just in case $p doesn't contain any slash, then it prepends ./ to it.

See the Shell Parameter Expansion section in the Bash Reference Manual for more info on the % and ## symbols.