linux cmd backup

[etaf]

To see etaf belongs to which group:

groups etaf 

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Change etaf's default group to new_group:

usermod -g new_group etaf

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find all the core file and remove them

find ~ -regex ".*core\.[0-9]*" | xargs rm

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redirect stderr to file

cmd 2> stderr.txt

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redirect stdout and stderr to file

cmd >file 2>&1
##first redirect stderr to stdout , then redirect stdout to file 
``

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vim replace

:%s/origin_pattern/new_string/cig

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kill multi process with one line

kill $(ps aux | grep '[p]ython csp_build.py' | awk '{print $2}')
Details on its workings are as follows:

first try kill -15 $(....)
if not help try kill -9

• The ps gives you the list of all the processes.
• The grep filters that based on your search string, [p] is a trick to stop you picking up the actual grep process itself.
• The awk just gives you the second field of each line, which is the PID.
• The $(x) construct means to execute x then take its output and put it on the command line. The output of that ps pipeline inside that construct above is the list of process IDs so you end up with a command like kill 1234 1122 7654.

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run command without shell

nohup command &

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format code

indent -linux x.cpp
or:
clang-format -i -style=xxx *.cpp

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arp scan

sudo arp-scan -I eth0 -l

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find excutabe file

find -type f -perm /u=x -exec ls -l {} \;

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find ip of a ASUS server which has open port 80;

sudo arp-scan -l | grep ASUS | awk '{print $1}' | xargs nmap -p 80 | grep -A 1 -B 3 "open"