System info status line for tmux

tmux-status.sh

#!/bin/bash
userhost="$(whoami)@$(hostname)"

# CPU per-core usage
cpu_usage() {
  awk '/^cpu[0-9]/ {
    cpu=$1; t=$2+$3+$4+$5+$6+$7+$8; i=$5;
    printf "%s,%d,%d\n", cpu, t, i
  }' /proc/stat > /tmp/cpu1
  sleep 0.5
  awk '/^cpu[0-9]/ {
    cpu=$1; t=$2+$3+$4+$5+$6+$7+$8; i=$5;
    cpu_t[cpu]=t; cpu_i[cpu]=i
  }
  END {
    while ((getline < "/tmp/cpu1") > 0) {
      split($0,a,",");
      cpu=a[1]; t1=a[2]; i1=a[3];
      t2=cpu_t[cpu]; i2=cpu_i[cpu];
      dt=t2 - t1; di=i2 - i1;
      if (dt > 0)
        printf " %d%%", (dt - di) * 100 / dt
    }
  }' /proc/stat
}

# Memory usage
mem_usage() {
  free -h | awk '/Mem:/ {print $3 "/" $2}'
}

# Disk usage of root filesystem
disk_usage() {
  df -h / | awk 'NR==2 {print $3 "/" $2}'
}

# Load average
load_avg() {
  uptime | awk -F'load average: ' '{print $2}' | tr -d ,
}

# Uptime in days
uptime_days() {
  awk '{print int($1/86400) "d"}' /proc/uptime
}

# Compose status line with tmux color formatting
echo "#[fg=red]${userhost}#[default] | #[fg=green]CPU:$(cpu_usage)#[default] | #[fg=cyan]MEM: $(mem_usage)#[default] | #[fg=yellow]DISK: $(disk_usage)#[default] | #[fg=magenta]LOAD: $(load_avg)#[default] | #[fg=blue]UPTIME: $(uptime_days)#[default]"