tcpdump to list HTTP requests source: http://stackoverflow.com/a/16610385

gistfile1.txt

man tcpdump | less -Ip examples

# tcpdump filter for HTTP GET 
sudo tcpdump -s 0 -A 'tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x47455420'

# tcpdump filter for HTTP POST 
sudo tcpdump -s 0 -A 'tcp dst port 80 and (tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x504f5354)'

# monitor HTTP traffic including request and response headers and message body
# cf. https://sites.google.com/site/jimmyxu101/testing/use-tcpdump-to-monitor-http-traffic
tcpdump -A -s 0 'tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)'
tcpdump -X -s 0 'tcp port 80 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)'