using grep and sed - I'm sure there is an easier way to get to this result

breadbin · 08-15-2025, 04:41 AM

I have finally got the result I was looking for, it only took me about an hour to get here! I am using the sensors command to show the computers temperatures and on this new computer there is loads of information. It is actually 47 lines long and finding the CPU and GPU temperatures isn't as easy as it could be. So I decided to dive into grep and sed, I have never really used them before, but I wanted to try to use them to get the result I wanted. Which is

Code:

CPU: 25.0°C 
GPU: 25.0°C

or whatever they are. And after a long process I managed it but I think it is embarrassingly noob and wondering if there was anything else I could have done differently for the future. The command I finally came up with is

Code:

sensors | sed "s/Tctl:/CPU/" | sed "s/junction:/GPU\    /" | grep -e "CPU" -e "GPU" | sed "s/([^)]*)//g"

I had to use the sed commands first to change the names because it wouldn't work after the grep commands. But I never really used pipes either so it is good practice.

The hardest part for me was the sed part at the end and it works but I had a hard time understanding how until I went to the GNU regular expression page and it seems to make a bit more sense now. The "junction:/GPU\ /" bit is to format the output under each other because I presume the CPU had an extra tab inserted.

Not pretty but it works and I am hoping to somehow use the watch command to keep an eye on them and maybe in the future put the output in a widget or something. I'm sure there are already widgets that do this and do it better but it is about the learning for me.

viel · 08-15-2025, 04:44 AM

What is the full sort of sensors?

Code:

Adapter: ISA adapter
Package id 0:  +88.0°C  (high = +100.0°C, crit = +100.0°C)
Core 0:        +87.0°C  (high = +100.0°C, crit = +100.0°C)
Core 1:        +88.0°C  (high = +100.0°C, crit = +100.0°C)
Core 2:        +77.0°C  (high = +100.0°C, crit = +100.0°C)
Core 3:        +79.0°C  (high = +100.0°C, crit = +100.0°C)

iwlwifi_1-virtual-0
Adapter: Virtual device
temp1:            N/A

acpitz-acpi-0
Adapter: ACPI interface
temp1:        +85.0°C  (crit = +103.0°C)

nouveau-pci-0100
Adapter: PCI adapter
GPU core:         N/A  (min =  +0.60 V, max =  +1.20 V)
temp1:            N/A  (high = +95.0°C, hyst =  +3.0°C)
                       (crit = +105.0°C, hyst =  +5.0°C)
                       (emerg = +135.0°C, hyst =  +5.0°C)

asus-isa-0000
Adapter: ISA adapter
cpu_fan:     3200 RPM
temp1:        +85.0°C

pch_skylake-virtual-0
Adapter: Virtual device
temp1:        +57.5°C

BAT0-acpi-0
Adapter: ACPI interface
in0:          14.40 V

breadbin · 08-15-2025, 04:50 AM

spd5118-i2c-16-53
Adapter: SMBus PIIX4 adapter port 0 at 0b00
temp1: +32.8°C (low = +0.0°C, high = +55.0°C)
(crit low = +0.0°C, crit = +85.0°C)

k10temp-pci-00c3
Adapter: PCI adapter
Tctl: +43.5°C
Tccd1: +33.2°C

amdgpu-pci-0300
Adapter: PCI adapter
vddgfx: 91.00 mV
fan1: 0 RPM (min = 0 RPM, max = 6000 RPM)
edge: +31.0°C (crit = +100.0°C, hyst = -273.1°C)
(emerg = +105.0°C)
junction: +32.0°C (crit = +110.0°C, hyst = -273.1°C)
(emerg = +115.0°C)
mem: +30.0°C (crit = +105.0°C, hyst = -273.1°C)
(emerg = +110.0°C)
PPT: 4.00 W (cap = 170.00 W)

nvme-pci-0f00
Adapter: PCI adapter
Composite: +36.9°C (low = -273.1°C, high = +74.8°C)
(crit = +79.8°C)
Sensor 2: +51.9°C (low = -273.1°C, high = +65261.8°C)

iwlwifi_1-virtual-0
Adapter: Virtual device
temp1: +25.0°C

spd5118-i2c-16-51
Adapter: SMBus PIIX4 adapter port 0 at 0b00
temp1: +32.2°C (low = +0.0°C, high = +55.0°C)
(crit low = +0.0°C, crit = +85.0°C)

amdgpu-pci-1000
Adapter: PCI adapter
vddgfx: 1.19 V
vddnb: 1.01 V
edge: +40.0°C
PPT: 28.06 W

r8169_0_800:00-mdio-0
Adapter: MDIO adapter
temp1: +32.0°C (high = +120.0°C)

breadbin · 08-15-2025, 04:52 AM

I am guessing the k10temp is the cpu and the first amdgpu is the gpu. Not sure why there are 2 amdgpu sections but it is a lot to look at.

viel · 08-15-2025, 04:52 AM

Well you need to put it like code to see spaces ... to I can process it fine.

pan64 · 08-15-2025, 05:11 AM

https://zzzcode.ai/code-refactor?id=...d-c682eacf3347

syg00 · 08-15-2025, 06:07 AM

Field based processing is way better handled in something like awk - or perl.
If you don't know either, sed can handle all this in one invocation - there is never any need to pipe to grep, sed has the logic primitives to do it all. A little (lot) more arcane than awk, but if you don't want to learn yet another tool, sed will suffice. Concentrate on the data you want, not the other fluff. Something like this should work (untested).

Code:

sed -nE "/Tctl:/ {s/.+(\+.+C).*/CPU:\t\1/p} ; /junction:/ {s/.+(\+.+C).+/GPU:\t\1/p}"

boughtonp · 08-15-2025, 07:12 AM

What version of sensors? Does it have the new -J flag for useful JSON output (which can then be parsed with a single jq call?

breadbin · 08-15-2025, 09:48 AM

Quote:

Originally Posted by pan64

https://zzzcode.ai/code-refactor?id=...d-c682eacf3347

Thanks, I thought there might be something like this available. I'm sure there is an AI thing that can write the whole thing too from scratch.

Quote:

Originally Posted by syg00

Field based processing is way better handled in something like awk - or perl.
If you don't know either, sed can handle all this in one invocation - there is never any need to pipe to grep, sed has the logic primitives to do it all. A little (lot) more arcane than awk, but if you don't want to learn yet another tool, sed will suffice. Concentrate on the data you want, not the other fluff. Something like this should work (untested).
Code:
sed -nE "/Tctl:/ {s/.+(\+.+C).*/CPU:\t\1/p} ; /junction:/ {s/.+(\+.+C).+/GPU:\t\1/p}"

I don't have a problem using other tools, maybe I would if I knew more about any of them, I thought sed was probably best for it. It looks like the sort of job it was created for

Quote:

Originally Posted by boughtonp

What version of sensors? Does it have the new -J flag for useful JSON output (which can then be parsed with a single jq call?

It is version 3.6.0 so yes it does have the json output, would that be easier to work with?

MadeInGermany · 08-15-2025, 02:31 PM

As others said, awk is best here:

Code:

sensors | awk '$1=="Tctl:" {print "CPU:",$2} $1=="junction:" {print "GPU:",$2}'