Created
          August 6, 2020 07:55 
        
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    AWK to get details from /proc/net/tcp and /proc/net/udp when netstat and lsof are not available 
  
        
  
    
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  | # Based on gist https://gist.github.com/staaldraad/4c4c80800ce15b6bef1c1186eaa8da9f | |
| # - added TCP states | |
| awk 'BEGIN{states["01"]="TCP_ESTABLISHED" | |
| states["02"]="TCP_SYN_SENT" | |
| states["03"]="TCP_SYN_RECV" | |
| states["04"]="TCP_FIN_WAIT1" | |
| states["05"]="TCP_FIN_WAIT2" | |
| states["06"]="TCP_TIME_WAIT" | |
| states["07"]="TCP_CLOSE" | |
| states["08"]="TCP_CLOSE_WAIT" | |
| states["09"]="TCP_LAST_ACK" | |
| states["0A"]="TCP_LISTEN" | |
| states["0B"]="TCP_CLOSING" | |
| states["0C"]="TCP_NEW_SYN_RECV" | |
| } | |
| function hextodec(str,ret,n,i,k,c){ | |
| ret = 0 | |
| n = length(str) | |
| for (i = 1; i <= n; i++) { | |
| c = tolower(substr(str, i, 1)) | |
| k = index("123456789abcdef", c) | |
| ret = ret * 16 + k | |
| } | |
| return ret | |
| } | |
| function getIP(str,ret){ | |
| ret=hextodec(substr(str,index(str,":")-2,2)); | |
| for (i=5; i>0; i-=2) { | |
| ret = ret"."hextodec(substr(str,i,2)) | |
| } | |
| ret = ret":"hextodec(substr(str,index(str,":")+1,4)) | |
| return ret | |
| } | |
| NR > 1 {{if(NR==2)print "Local - Remote";local=getIP($2);remote=getIP($3)}{print local" - "remote" "states[$4]}}' /proc/net/tcp | 
  
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Thank you for this.
I updated it a bit to make it quickly reusable
https://gist.github.com/petermueller/1b837eddc443857b2051f739818cfad7