Or use python:
#!/usr/bin/env python
with open('text.txt', 'r+') as f:
f.write(''.join([line*3 for line in f])+str(f.seek(0,0)).strip('None'))
Note: The above code is insanely hack-ish because I wanted it to be 2 lines.

The more readable version:
with open('text.txt', 'r+') as f:
lines = ''.join([line*3 for line in f])
f.seek(0, 0)
f.write(lines)
With command line args:
#!/usr/bin/env python
import sys
if __name__ == '__main__':
if len(sys.argv) < 3:
print 'Usage: ' + sys.argv[0] + ' <filename> <multiplier number>'
sys.exit(0)
filename = str(sys.argv[1])
multiplier = int(sys.argv[2])
with open(filename, 'r+') as f:
lines = ''.join([line*multiplier for line in f])
f.seek(0, 0)
f.write(lines)
sys.exit(0)
Usage example:
I like offending people. People who get offended should be offended. --
Linus Torvalds
