As a cloud engineer, mastering advanced Linux commands is crucial for efficient cloud management. Here’s a list of the top 10 commands you should know:
1. jq (JSON Processor)
Extract a specific field from a JSON file
jq '.name' data.jsonFilter JSON data based on a condition
jq '.age > 25' data.jsonConvert JSON to YAML
jq -r tostring data.json | yq -2. grep (Global Regular Expression Print)
Search for a string in a file
grep "error" log.txtCount the occurrences of a pattern
grep -c "warning" log.txtExclude lines that match a pattern
grep -v "info" log.txt3. sed (Stream Editor)
Replace a string with another
sed 's/old/new/g' file.txtDelete a specific line
sed '10d' file.txtInsert a line before a specific pattern
sed '/pattern/i\new line' file.txt4. awk (Pattern Scanning and Processing Language)
Print specific fields from a CSV file
awk -F, '{print $1, $3}' data.csvCalculate the sum of a column
awk -F, '{sum+=$2} END {print sum}' data.csvCreate a histogram of values
awk '{print $1, $2 | "sort -nk2"}' data.csv5. curl (Client for URLs)
Send an HTTP GET request
curl https://example.comPost data to an API
curl -X POST -d '{"name": "John"}' https://example.com/apiDownload a file
curl -O https://example.com/file.zip6. dig (Domain Information Groper)
Lookup DNS records for a domain
dig example.comCheck the MX records for a domain
dig MX example.comTrace the route to a server
dig +trace example.com7. netstat (Network Statistics)
List all active network connections
netstat -anShow the listening ports
netstat -lMonitor network traffic in real-time
netstat -c8. tcpdump (Network Traffic Capture)
Capture network traffic on a specific interface
tcpdump -i eth0Filter traffic based on a protocol
tcpdump -i eth0 'tcp port 80'Save captured traffic to a file
tcpdump -i eth0 -w traffic.pcap9. lsof (List Open Files)
List all open files by a specific process
lsof -p 1234Find out which process is using a specific file
lsof /path/to/fileClose a file descriptor
lsof -i :1234 -c kill10. ps (Process Status)
List all running processes
ps -efShow detailed information about a specific process
ps -aux | grep 1234Kill a process
ps -ef | grep 1234 | awk '{print $2}' | xargs kill