Score:1

Ubuntu

bash: How to create a key,value pairs from .txt file in linux

hariraj

2/28/23, 8:45 AM

w | awk 'NR==1 {print $1}' >file.txt
cat file
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
lava1    pts/0    157.48.149.102   05:03   31.00s  0.31s  0.31s -bash
azureuse pts/1    157.48.149.102   07:26    0.00s  0.07s  0.05s w

From the above text file I want to create key,value pairs like json format as below is the expected output:

{
 "USER" : "lava1",
 "TTY" : "pts/1",
 "FROM" : "157.47.49.254",
 "LOGIN" : "12:32",
 "IDLE" : "5.00s"
}

318

0 + 0

bash

text-processing

Rinzwind

2/28/23, 8:56 AM

In bash? see https://stackoverflow.com/questions/48470049/build-a-json-string-with-bash-variables

Andrej Podzimek

2/28/23, 6:21 PM

The `awk` command in your question makes no sense. First, it writes into a different file, not into the one you `cat` below. Second, `file.txt` will contain the current time (from `w` output), not the lines that `file` contains.

Andrej Podzimek

2/28/23, 6:32 PM

`PROCPS_USERLEN=32 PROCPS_FROMLEN=32 w | tail -n+2 | while read -r user tty from login idle discard; do echo -e '{\n "USER" : "'"$user"'",\n "TTY" : "'"$tty"'",\n "FROM" : "'"$from"'",\n "LOGIN" : "'"$login"'",\n "IDLE" : "'"$idle"'"\n}'; done` Anyway, the two environment variables show why parsing the output from `w` is simply a bad idea. Not to mention that you may need to also export (e.g.) `LC_ALL=en_US.UTF-8` to get consistent output. Otherwise the login date will be spelled out in the current locale etc.

Score:2

Ubuntu

steeldriver

2/28/23, 11:55 AM

I'd suggest Miller for something like this - specifically, convert from "pretty print" to JSON:

$ mlr --ipprint --ojson cat file
{ "USER": "lava1", "TTY": "pts/0", "FROM": "157.48.149.102", "LOGIN@": "05:03", "IDLE": "31.00s", "JCPU": "0.31s", "PCPU": "0.31s", "WHAT": "-bash" }
{ "USER": "azureuse", "TTY": "pts/1", "FROM": "157.48.149.102", "LOGIN@": "07:26", "IDLE": "0.00s", "JCPU": "0.07s", "PCPU": "0.05s", "WHAT": "w" }

Selecting specific fields with cut and renaming the LOGIN@ field:

$ mlr --ipprint --ojson cut -f USER,TTY,FROM,LOGIN@,IDLE then rename LOGIN@,LOGIN file
{ "USER": "lava1", "TTY": "pts/0", "FROM": "157.48.149.102", "LOGIN": "05:03", "IDLE": "31.00s" }
{ "USER": "azureuse", "TTY": "pts/1", "FROM": "157.48.149.102", "LOGIN": "07:26", "IDLE": "0.00s" }

0 + 0

Score:0

Ubuntu

Christian Bongiorno

3/25/24, 6:42 PM

I saw this issue and tried to figure it out. I got close, then hit a couple of walls. Ultimately though, your answer is here:

All I ask for is some credit for taking up the charge on this one. Upvotes!

+ 0

Score:0

Ubuntu

glenn jackman

2/28/23, 8:30 PM

Since you want to produce JSON, let's use jq

w \
| tail -n +3 \
| jq -R '. | split("\\s+"; "g") | {USER:.[0], TTY:.[1], FROM:.[2], LOGIN:.[3], IDLE:.[4]}'

I'm using tail to skip the first 2 lines of w output.

0 + 0

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: bash: How to create a key,value pairs from .txt file in linux

TH: bash: วิธีสร้างคู่คีย์, ค่าจากไฟล์ .txt ใน linux

RO: bash: Cum se creează o pereche cheie, valoare din fișierul .txt în Linux

RU: bash: как создать пары ключ-значение из файла .txt в Linux

VI: bash: Cách tạo cặp khóa, giá trị từ tệp .txt trong linux

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