How to list one filename per output line in Linux?

There are several Linux commands available to list files and directories. By default, the ls command displays output in multiple columns across the terminal width. However, there are various methods to format the output so that each filename appears on a separate line, which is useful for scripting and better readability.

Default ls Command Behavior

The standard ls command displays files and directories in a multi-column format:

ls

api      cluster   docs LICENSE Makefile.generated_files pkg
staging  vendor
build    cmd       go.mod LICENSES _output plugin

This default behavior can make it difficult to process filenames individually, especially in scripts or when you need to count files.

Methods to List One Filename Per Line

Using the -1 Flag

The most straightforward method is using the -1 (dash one) flag with the ls command:

ls -1

api
build
CHANGELOG
CHANGELOG.md
cluster
cmd
code-of-conduct.md
CONTRIBUTING.md
docs
go.mod
go.sum
hack
LICENSE
LICENSES

This flag forces ls to display one entry per line, regardless of terminal width.

Using tr Command for Character Translation

You can pipe the output of ls to the tr command to replace spaces with newlines:

ls | tr " " "<br>"

api
build
CHANGELOG
CHANGELOG.md
cluster
cmd
code-of-conduct.md
CONTRIBUTING.md
docs
go.mod
go.sum
hack
LICENSE
LICENSES

The tr command translates or deletes characters. Here, it replaces each space character with a newline character.

Combining ls with cat

Another approach involves using cat with the -a flag:

ls -a | cat

.
..
api
build
CHANGELOG
CHANGELOG.md
cluster
cmd
code-of-conduct.md
CONTRIBUTING.md
docs
go.mod

Note: The -a flag includes hidden files (those starting with a dot), including the current directory (.) and parent directory (..).

Comparison of Methods

Additional Useful Variations

You can combine flags for more specific output:

ls -1a    # One per line including hidden files
ls -1l    # One per line with detailed information
ls -1t    # One per line sorted by modification time

Conclusion

The ls -1 command is the most efficient way to list one filename per line in Linux. While alternative methods using tr or cat achieve similar results, the -1 flag is specifically designed for this purpose and provides the cleanest solution for scripts and manual file management.