ref: 36b668246b2bc393d589b63b7c4f84cbe1185d45
dir: /rc/bin/uptime/
#!/bin/awk -f BEGIN{ getline sysname < "/dev/sysname"; getline < "/dev/time"; sec = sprintf("%d", $3/$4); ct = sprintf("%02d:%02d:%02d", sec%86400/3600, sec%86400%3600/60, sec%60); printf("%s up %d days, %s\n", sysname, sec/86400, ct); exit }