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Commands tagged netcat nc

Commands tagged netcat nc from sorted by
Terminal - Commands tagged netcat nc - 2 results
seq 1 255 | parallel -j+0 'nc -w 1 -z -v 192.168.1.{} 80'
2011-06-11 14:40:51
User: devrick0
Functions: seq
Tags: seq parallel netcat nc
1
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port scan using parallel

It takes over 5 seconds to scan a single port on a single host using nmap

time (nmap -p 80 192.168.1.1 &> /dev/null)

real 0m5.109s

user 0m0.102s

sys 0m0.004s

It took netcat about 2.5 minutes to scan port 80 on the class C

time (for NUM in {1..255} ; do nc -w 1 -z -v 192.168.1.${NUM} 80 ; done &> /dev/null)

real 2m28.651s

user 0m0.136s

sys 0m0.341s

Using parallel, I am able to scan port 80 on the entire class C in under 2 seconds

time (seq 1 255 | parallel -j255 'nc -w 1 -z -v 192.168.1.{} 80' &> /dev/null)

real 0m1.957s

user 0m0.457s

sys 0m0.994s

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nc -zw2 www.example.com 80 || echo http service is down | mail -s 'http is down' admin@example.com
2010-09-08 13:18:16
User: putnamhill
Functions: echo mail
Tags: bash mail netcat nc
1
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Check a server is up. If it isn't mail me.

This version uses netcat to check a particular service.

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