What is the Command to Merge Two Lines into One on Linux

If you want to be merge two line set to one, SED and AWK command can use for this.

For example create a file linuxfaq.txt and add below lines,

# vim linuxfaq.txt



First line

Second line

Third line

Fourth line

Now the output should look like,

# awk 'NR%2{printf $0" ";next;}1' sample.txt



First line Second line

Third line Fourth line

# sed 'N;s/\n/ /' sample.txt



First line Second line

Third line Fourth line

# paste -d " " - - < sample.txt

Multiple lines merge into one,

# cat sample.txt | xargs