List only regular files (but not directories) in current directory

ls -p | grep -v / 

This command lists all non-hidden files that aren't directories (regular files, links, device files, etc.). To also include hidden files, add the -A option to ls

It assumes none of the files have newline characters in their name. Adding a -q option to ls would transform all non-printable characters including newline to ?, guaranteeing they're on one line and so suitable for feeding to a line-based utility like grep and for printing on a terminal.

With zsh and Glob Qualifiers you can easily express it directly, e.g:

echo *(.)

will either only return the list of regular files or an error depending on your configuration.

For the non-directories:

echo *(^/)

(will include symlinks (including to directories), named pipes, devices, sockets, doors...)

echo *(-.)

for regular files and symlinks to regular files.

echo *(-^/)

for non-directories and no symlinks to directories either.

Also, see the D globbing qualifier if you want to include Dot files (hidden files), like *(D-.).

To list regular files only:

ls -al | grep '^-'

With symbolic links (to any type of file) included:

ls -al | grep '^[-l]'

Where the first character of the list describes the type of file, so - means that it's a regular file, for symbolic link is l.

Debian/Ubuntu

Print the names of the all matching files (including links):

run-parts --list --regex . .

With absolute paths:

run-parts --list --regex . "$PWD"

Print the names of all files in /etc that start with p and end with d:

run-parts --list --regex '^p.*d$' /etc