How to join multiple lines of file names into one

Question

I would like to join the result of ls -1 into one line and delimit it with whatever i want.

Are there any standard Linux commands I can use to achieve this?

Answer 1

sed -e :a -e '/$/N; s/\n/\\n/; ta' [filename]

Explanation:

-e - denotes a command to be executed
:a - is a label
/$/N - defines the scope of the match for the current and the (N)ext line
s/\n/\\n/; - replaces all EOL with \n
ta; - goto label a if the match is successful

Taken from my blog.

Answer 2

It looks like the answers already exist.

If you want a, b, c format, use ls -m ( Tulains Córdova’s answer)

Or if you want a b c format, use ls | xargs (simpified version of Chris J’s answer)

Or if you want any other delimiter like |, use ls | paste -sd'|' (application of Artem’s answer)

Answer 3

just bash

mystring=$(printf "%s|" *)
echo ${mystring%|}

Answer 4

Similar to the very first option but omits the trailing delimiter

ls -1 | paste -sd "," -

Answer 5

The sed way,

sed -e ':a; N; $!ba; s/\n/,/g'
  # :a         # label called 'a'
  # N          # append next line into Pattern Space (see info sed)
  # $!ba       # if it's the last line ($) do not (!) jump to (b) label :a (a) - break loop
  # s/\n/,/g   # any substitution you want

Note:

This is linear in complexity, substituting only once after all lines are appended into sed's Pattern Space.

@AnandRajaseka's answer, and some other similar answers, such as here, are O(n²), because sed has to do substitute every time a new line is appended into the Pattern Space.

To compare,

seq 1 100000 | sed ':a; N; $!ba; s/\n/,/g' | head -c 80
  # linear, in less than 0.1s
seq 1 100000 | sed ':a; /$/N; s/\n/,/; ta' | head -c 80
  # quadratic, hung

Answer 6

ls has the option -m to delimit the output with ", " a comma and a space.

ls -m | tr -d ' ' | tr ',' ';'

piping this result to tr to remove either the space or the comma will allow you to pipe the result again to tr to replace the delimiter.

in my example i replace the delimiter , with the delimiter ;

replace ; with whatever one character delimiter you prefer since tr only accounts for the first character in the strings you pass in as arguments.