Commands tagged sysfs (5)

  • Needs to be run in a battery sysfs dir, eg. /sys/class/power_supply/BAT0 on my system. Displays the battery's current charge and the rate per-second at which energy is {dis,}charging. All values are displayed as percentages of "full" charge. The first column is the current charge. The second is the rate of change averaged over the entire lifetime of the command (or since the AC cable was {un,}plugged), and the third column is the rate of change averaged over the last minute (controlled by the C=60 variable passed to awk). The sample output captures a scenario where I ran 'yes' in another terminal to max out a CPU. My battery was at 76% charge and you can see the energy drain starts to rise above 0.01% per-second as the cpu starts working and the fan kicks in etc. While idle it was more like 0.005% per-second. I tried to use this to estimate the remaining battery life/time until fully charged, but found it to be pretty useless... As my battery gets more charged it starts to charge slower, which meant the estimate was always wrong. Not sure if that's common for batteries or not. Show Sample Output


    -1
    while cat energy_now; do sleep 1; done |awk -v F=$(cat energy_full) -v C=60 'NR==1{P=B=$1;p=100/F} {d=$1-P; if(d!=0&&d*D<=0){D=d;n=1;A[0]=B=P}; if(n>0){r=g=($1-B)/n;if(n>C){r=($1-A[n%C])/C}}; A[n++%C]=P=$1; printf "%3d %+09.5f %+09.5f\n", p*$1, p*g, p*r}'
    sqweek · 2015-09-19 15:45:40 0
  • Shows all block devices in a tree with descruptions of what they are.


    3
    lsblk -o NAME,TYPE,FSTYPE,LABEL,SIZE,MODEL,MOUNTPOINT
    BasketCase · 2012-09-12 15:30:25 0
  • Use `scsi_id` to positively identify which LUNs are which (i.e. compare with the list of LUNs you created on your disk array) (shown: RHEL5 usage) Debian usage: # for i in /dev/sd* ; do wwn=`/lib/udev/scsi_id -g --device $i` ; [ "$wwn" != "" ] && echo -e ${i##*/}'\t'$wwn ;done Show Sample Output


    1
    for i in /sys/block/sd* ; do wwn=`/lib/udev/scsi_id -g -s /block/${i##*/}` ; [ "$wwn" != "" ] && echo -e ${i##*/}'\t'$wwn ;done
    mhs · 2012-09-12 14:14:53 0
  • `blkid` is an interface to libuuid - it can read Device Mapper, EVMS, LVM, MD, and regular block devices. -c /dev/null - Do not use cached output from /etc/blkid.tab or /etc/blkid/blkid.tab (RHEL) -i - Display I/O Limits (aka I/O topology) information (not available in RHEL) -p - Low-level superblock probing mode (not available in RHEL) Show Sample Output


    2
    blkid -c /dev/null
    mhs · 2012-09-12 13:34:41 2
  • Requires sysfs mounted on /sys - may only be useful for Linux systems. Could also use "printf '%-8s %s\n' $(basename $f) $(cat $f/address)" instead of echo. Show Sample Output


    4
    for f in /sys/class/net/*; do echo -e "$(basename $f)\t$(cat $f/address)"; done
    Mozai · 2011-05-19 22:38:46 0

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