How to concatenate multiple lines of output into one line?

Question

If I run the command cat file | grep pattern cat file | grep pattern , I get a lot of lines of output. How do you combine all the lines into one line, effectively replacing each "\n" with "\" " (ending with " followed by a space)?

cat file | grep pattern | xargs sed s/\n/ /g cat file | grep pattern | xargs sed s/\n/ /g does not work for me.

Answer 1

Use tr '\n' ' ' to translate all newlines to spaces:

 $ grep pattern file | tr '\n' ' ' 

Note: grep reads files, cat merges files. Not cat file | grep cat file | grep !

Edit:

tr can only handle single character translations. You can use awk to change the output record separator, for example:

 $ grep pattern file | awk '{print}' ORS='" ' 

This will change:

 one two three 

at

 one" two" three" 

Answer 2

The pipeline output on xargs combines each line of output into one line with spaces:

 grep pattern file | xargs 

Or any command, for example. ls | xargs ls | xargs . The default limit for xargs output is ~ 4096 characters, but can be increased, for example. xargs -s 8192 .

grep xargs

Answer 3

In bash echo without quotes, remove quotes, tabs and a few spaces

 echo $(cat file) 

Answer 4

It may be what you want

 cat file | grep pattern | paste -sd' ' 

As for your editing, I'm not sure what that means, maybe it?

 cat file | grep pattern | paste -sd'~' | sed -e 's/~/" "/g' 

(this assumes ~ not found in file )

Answer 5

Here is a method using the ex editor:

• J for all lines and p rint for standard output:

   $ ex +%j +%p -scq! file 

• J in all lines in place (in a file):

   $ ex +%j -scwq file 

  ^{Note. This will concatenate all the lines inside the it-self file!}