mjhjmtu

I have a file containing full path names of files an directories.

From this list I would like to filter out any pathnames that reference directories so that I am left with a list containing only file paths.

Can anybody think of an elegant solution?

while IFS= read -r file; do
 [ -d "$file" ] || printf '%sn' "$file"
done <input_file

Would print the files that are not determined to be of type directory (or symlink to directory). It would leave all other type of files (regular, symlink (except to directories), sockets, pipes...) and those for which the type cannot be determined (for instance because they don't exist or are in directories which you don't have search permission to).

Some variations depending on what you meant by file and directory (directory is one of many types of files on Unix):

• 
  

  the file exists (after symlink resolution) and is not of type directory:

  
  
  

  [ -e "$file" ] && [ ! -d "$file" ] && printf '%sn' "$file"
  

  
  


• 
  

  file exists and is a regular file (after symlink resolution):

  
  
  

  [ -f "$file" ] && printf '%sn' "$file"
  

  
  


• 
  

  file exists and is a regular file before symlink resolution (excludes symlinks):

  
  
  

  [ -f "$file" ] && [ ! -L "$file" ] && printf '%sn' "$file"
  

  
  



• etc.

Assuming the file contains one file path per line, with zsh:

printf '%sn' $(f)^"$(<file)"(N^/)

would print those that do exist (that we can tell exist) and are not determined to be of type directory (change / to -/ to also discard symlinks to directories).

Since you mention xargs, with the GNU implementation (for -d and -r), and assuming none of the file paths start with - or are find predicates (like !) you could do:

xargs -rd 'n' sh -xc 'exec find "$@" -prune ! -type d' sh < file

Replace -type with -xtype (assuming GNU find) to also exclude symlinks to directories.