How can I duplicate a line on a file?

IRJ

I am running a command to generate a random password to a file. It creates a one line file, but I need the file to be two lines and have the same password on both lines (obviously)

tr -cd '[:alnum:]' < /dev/urandom | fold -w30 | head -n1 > /tmp/tmp1.txt

Essentially file looks like this:

cat /tmp/tmp1.txt 
zPZ0ud81Q0gSjXKTDSLuP2Wz8PQIds

I need it to look like this:

cat /tmp/tmp1.txt 
zPZ0ud81Q0gSjXKTDSLuP2Wz8PQIds
zPZ0ud81Q0gSjXKTDSLuP2Wz8PQIds

DustinB3403

Sed should be able to do this.

From here

sed -n $a,$b'p' infile

IRJ

@DustinB3403 said in How can I duplicate a line on a file?:

Sed should be able to do this.

From here

sed -n $a,$b'p' infile

How does a = 2 and b =4 ? I am not understanding that part.

DustinB3403

@IRJ In that example a is line 2 and b is line 4.

IRJ

Here is a much simplier way to do this.

head -1 /tmp/tmp1.txt >> /tmp/tmp1.txt