How can I add the current date or time to end of each line in file?

Question

I have a file called data.txt.

I want to add the current date, or time, or both to the beginning or end of each line.

I have tried this:

awk -v v1=$var ' { printf("%s,%s\n", $0, v1) } ' data.txt > data.txt

I have tried this:

sed "s/$/,$var/" data.txt

Nothing works.

Can someone help me out here?

Solution 1

How about :

cat filename | sed "s/$/ `date`/"

Solution 2

The problem with this

awk -v v1=$var ' { printf("%s,%s\n", $0, v1) } ' data.txt > data.txt

is that the > redirection happens first, and the shell truncates the file. Only then does the shell exec awk, which then reads an empty file.

Choose one of these:

sed -i "s/\$/ $var/" data.txt

awk -v "date=$var" '{print $0, date}' data.txt > tmpfile && mv tmpfile data.txt

However, does your $var contain slashes (such as "10/04/2011 12:34") ? If yes, then choose a different delimiter for sed's s/// command: sed -i "s@\$@ $var@" data.txt

Comments

[fedorqui]

Good one, I guess you can even use awk -v date="$(date)" '$0=$0date' file.

[s3n0]

Or use cat filename | sed "s/^/`date` /" to add a timestamp to the beginning of each line.