When working with the ps command in Linux, a common requirement is to filter the output while keeping the column headers intact. The default behavior shows headers only for the first line, which disappears when piping to grep:

ps aux | grep GMC

This loses valuable context about what each column represents.


Here are three effective methods to maintain headers while filtering:

Method 1: Using the --headers flag (ps v3.3.0+)
ps --headers aux | grep -E "PID|GMC"

Method 2: Using awk for precise control
ps aux | awk 'NR==1 || /GMC/'

Method 3: Creating a custom function
Add this to your ~/.bashrc:

psg() {
  ps aux | awk -v pattern="$1" 'NR==1 || $0 ~ pattern'
}

Then use: psg GMC


In the example output:
root 32017 1 83 May03 ? 6-22:01:17 /scripts/GMC/PNetT-5.1-SP1/PNetTNetServer.bin

The 6-22:01:17 does indeed indicate the process has been running for:

6 days
22 hours
1 minute
17 seconds



The second column (32017 in the example) is indeed the PID. To terminate:
kill 32017

For graceful termination:
kill -15 32017

For forced termination:
kill -9 32017


For more precise process management:

Find all processes older than 3 days:
ps -eo pid,etime,cmd | awk '{split($2,a,"-"); if(a[1]>=3) print}'

Get full process tree with headers:
ps -f --forest | awk 'NR==1 || /GMC/'

When monitoring processes on Linux systems, developers often need to combine ps with grep while keeping the column headers visible. This becomes particularly important when:

• Monitoring long-running processes
• Debugging service issues
• Managing process trees

# Method 1: Using header preservation
ps aux | head -n 1; ps aux | grep GMC

# Method 2: Using BSD-style output format
ps -eo pid,user,cmd | grep -E 'PID|GMC'

# Method 3: Using awk for better control
ps aux | awk 'NR==1 || /GMC/'

The format 6-22:01:17 in ps output indicates:

• 6- = 6 days
• 22: = 22 hours
• 01: = 1 minute
• 17 = 17 seconds

Key columns in ps output:

USER     PID  %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root   32017  83.0  2.1 1456788 173496 ?      Sl   May03  6-22:01:17 /scripts/GMC/PNetT-5.1-SP1/PNetTNetServer.bin

To terminate this process:

kill 32017  # Graceful termination
kill -9 32017  # Forceful termination (use as last resort)

For comprehensive process information:

# Show process tree
pstree -p 32017

# Show open files
lsof -p 32017

# Continuous monitoring
watch -n 1 'ps aux | head -n 1; ps aux | grep GMC'

Consider these modern alternatives:

• htop - Interactive process viewer
• pgrep - Process grep utility
• systemctl - For systemd-managed services