This article summarizes frequently used Unix-like system commands for daily development, troubleshooting, and system monitoring. Each command includes practical usage examples and brief explanations to help you quickly find and understand essential tools.
Commands
tcpdump
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sudo tcpdump -i any src port 13400 or dst port 13400
mount
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mount -o remount,rw <path>
ps (process status)
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ps aux | grep <-i> <xxx>
# check related precess information and reserver first line.ps -eo pid,ppid,user,cmd | awk 'NR==1 || /<key_word>/'| less -S
# sz: viture memory usage, unit: page/4k, ps -eo pid,ppid,user,cmd,pcpu,sz,rss | awk 'NR==1 || /<key_word>/'| less -S
vmstat
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2
#check virtual memory usagevmstat -Sm 1
top
Type Shift + P: Sort by CPU load in descending order
Type Shift + M: Sort by memory usage in descending order
Type c: Show complete command.
Type E: Switching unit.
Network
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lsof -i :<port> # check port's process# -t: TCP, -u: UDP, -l: only listening, -n: don't parse servername, # -p: show port process informationss -tulnp | grep <"process name">
ss -tulnp | grep <":port">
# show first line titless -an | awk 'NR==1 || /:13400/'
