How to Show Per‑Process Memory Usage in MB/GB Using awk and ps

Method 1: Simple MB conversion

ps -eo pid,rss,cmd --sort=-rss | awk 'NR>1 {printf "%-10s %-10s %-50s
", $1, $2/1024 "MB", $3}'

Explanation: -e: show all processes. -o pid,rss,cmd: output PID, RSS (in KB), and command name. --sort=-rss: sort by RSS descending. NR>1: skip the header line. %-10s: left‑align a string in a 10‑character field. $2/1024 "MB": convert RSS from KB to MB and append the unit. $3: the command name.

To display values in gigabytes, divide by 1024 twice:

ps -eo pid,rss,cmd --sort=-rss | awk 'NR>1 {printf "%-10s %-10s %-50s
", $1, $2/1024/1024 "GB", $3}'

Method 2: Table with KB header

ps -eo pid,rss,cmd --sort=-rss | awk '
BEGIN { printf "%-10s %-10s %-50s
", "PID", "RSS(KB)", "CMD" }
NR>1 { printf "%-10s %-10dKB %-50s
", $1, $2, $3 }'

Key points: BEGIN { … } runs before any input is processed, printing the table header. printf formats each line; %-10dKB prints the RSS as an integer followed by the literal "KB". NR is awk's built‑in line counter; the condition NR>1 skips the header generated by ps. $1, $2, $3 correspond to PID, RSS, and command name respectively.

Method 3: Automatic unit conversion (KB/MB/GB/B)

ps aux | awk '
BEGIN {
    KB = 1024;
    MB = KB * 1024;
    GB = MB * 1024;
}
NR > 1 {
    mem = $6; # RSS column in KB
    if (mem > GB) {
        printf "%s (%s) - %.2f GB
", $11, $2, mem/GB;
    } else if (mem > MB) {
        printf "%s (%s) - %.2f MB
", $11, $2, mem/MB;
    } else if (mem > KB) {
        printf "%s (%s) - %.2f KB
", $11, $2, mem/KB;
    } else {
        printf "%s (%s) - %d B
", $11, $2, mem;
    }
}'

This script defines conversion constants, extracts the RSS field ($6), and prints the memory usage using the most appropriate unit, showing the command name ($11) and the owning user ($2).