45 Must‑Know Linux Command Combos for Everyday Ops – Boost Efficiency

This article summarizes 45 frequently used and highly efficient Linux commands, covering file operations, search and cleanup, system monitoring, log analysis, text processing, network capture, and disk cleanup, which together address about 99% of daily operations needs.

1. Batch File Operations

Batch creation: touch haodao{1..100}.py Generate large file quickly: dd if=/dev/zero of=test.txt bs=1M count=1024 Five ways to empty a file: > file, truncate -s 0 file, cat /dev/null > file, etc.

2. Advanced find Search & Cleanup

Search by name, type, permission, size, or time.

Examples:

By suffix: find . -name "*.py" By permission: find . -type f -perm 777 By size range: find . -size +100M -size -1G By time + name for cleanup:

find . -mtime +7 -name "*.py" | xargs rm -rf

3. System Resource Monitoring

View CPU model and core count: cat /proc/cpuinfo | grep name | uniq -c Top 20 memory/CPU consuming processes:

Memory: ps aux | sort -rnk 4 | head -20 CPU: ps aux | sort -rnk 3 | head -20 Run command in background:

nohup cmd > /dev/null 2>&1 &

4. Log and Access Analysis

Tomcat log analysis examples:

Count IPs in a time window: awk '{print $4,$1}' access.log | grep "11/Dec/2022:09" Top 20 IPs by request frequency:

awk '{print $1}' access.log | sort | uniq -c | sort -nr | head -20

Pages visited by a specific IP:

grep ^IP access.log | awk '{print $7}'

5. Text Processing with sed

Replace strings: sed -i 's/haodao/HAODAO/g' file.py Replace paths: sed -i 's:/etc/dhcp:/home:g' file.py Other tricks: add/remove content at line start/end, delete comments, insert before/after specific lines, etc.

6. Network Capture and Port Analysis

Precise packet capture with tcpdump:

Specific port: tcpdump -i ens33 port 8080 -n IP range: tcpdump portrange 80-443 -i ens33 -n ICMP from source IP: tcpdump icmp and src 192.168.20.231 -i ens33 -n Top IPs connecting to a port:

netstat -anlp | grep 80 | awk '{print $5}' | awk -F: '{print $1}' | sort | uniq -c | sort -nr | head -15

7. Disk and Directory Cleanup

Identify large files in /var: du -xBM --max-depth=2 /var | sort -rn | head -20 Top 10 large files in current directory: du -s * | sort -n | tail One‑sentence summary: 45 command combos form a full‑stack ops toolbox covering file handling, system monitoring, log analysis, network troubleshooting, text processing, and disk cleanup, solving almost all daily Linux administration scenarios.