Sujet : JSON And The Command Line
De : ldo (at) *nospam* nz.invalid (Lawrence D'Oliveiro)
Groupes : comp.unix.shellDate : 11. Aug 2024, 05:50:44
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <v99fv3$33qsp$1@dont-email.me>
User-Agent : Pan/0.159 (Vovchansk; )
Quite a few Linux utilities have the option to format their output as
JSON, for easy subsequent processing with commands like jq
<
https://manpages.debian.org/1/jq.1.en.html>.
For example, here’s what part of the output from “lscpu -J” looks like
on one of my machines:
{
"lscpu": [
{
"field": "Architecture:",
"data": "x86_64"
},{
"field": "CPU op-mode(s):",
"data": "32-bit, 64-bit"
},{
"field": "Address sizes:",
"data": "36 bits physical, 48 bits virtual"
},{
"field": "Byte Order:",
"data": "Little Endian"
},{
"field": "CPU(s):",
"data": "8"
},{
...
}
That’s a bit verbose, isn’t it? jq can still select information from
here, but wouldn’t it look a bit neater if instead of
{
"field": «key»,
"data": «value»
}
you had the more concise
{«key»: «value»}
?
Actually it’s quite easy to do this transformation. jq has built-in
functions “to_entries” and “from_entries” which can convert between
the verbose and concise layouts, but it only recognizes names like
“key” and “value”, not “field” and “data”.
Never mind: it’s easy enough to remap the names. Putting it all
together, including pulling out the lone “lscpu” field from the
original struct, here is the JSON processing pipeline:
lscpu -J | jq '.lscpu | map({"key" : .field, "value" : .data}) | from_entries'
And the initial part of the corresponding output:
{
"Architecture:": "x86_64",
"CPU op-mode(s):": "32-bit, 64-bit",
"Address sizes:": "36 bits physical, 48 bits virtual",
"Byte Order:": "Little Endian",
"CPU(s):": "8",
...
}