Text Processing – Collapsing Multiple Lines into One

newlinestext processing

I have a file containing a a large number of lines, each of which contains a bunch of numbers which are separated by spaces. I process this data in a pipe in some way, and then I want to collapse the multiple lines into a single line of all the numbers separated by spaces.

Is there a standard command-line utility I can use to do this? It seems like most line-by-line utilities won't mess with the newlines…

Best Answer

That's why you don't use line-by-line utilities for this.

$ tr '\n' ' ' < input.txt > output.txt

Related Solutions

Grep exact number of digits and some other characters

grep -vxE '([0-9]{5}[,-])*[0-9]{5}'

Would report the incorrect lines.

Or if you also want to forbid 12345-12345-12345:

num='[0-9]{5}'
num_or_range="$num(-$num)?"
grep -vxE "($num_or_range,)*$num_or_range"

How to both extract a specific line in a text file as well as multiple lines containing a specific string

Just change the grep output to append,

grep "string" source.txt >> destination.txt

Best Answer

Related Solutions

Grep exact number of digits and some other characters

How to both extract a specific line in a text file as well as multiple lines containing a specific string

Related Question