linking standard output to standard input using json file

[lusty mural]

Hello everyone !!

I have a json file and I want to use linux to search a particular filename and pipe it's output its key value into another touch command. How can I do this ?

basically, which commands use standard input and standard output ?

[vast kiln]

could you give a small snippet from the json file and the expected output?

[torpid dew]

you need to grep for the specific filename then likely use awk in some way to strip out the commas and braces then pipe that into touch

in all honesty if you know python itd probably be easier to just use it

[vast kiln]

jq is a decent tool for this, but Anmac hasn't yet told us the final goal, only a mid-step goal

which is kinda like the xy problem
https://xyproblem.info/

[torpid dew]

assuming jq searches for a key and spits out a value in a json file just jq <key> | strip out bad characters | touch

if jq just outputs whats within the quotes then just jq <key> | touch

touch accepts standard input, but does not output anything (unless there's an option to make it do that)

[vast kiln]

touch is a command meant for updating timestamps on files. Although you can use it to create files, that is not what it is meant for and probably should not be used for that purpose, but that is a whole debate.

[sage hornet]

specific file name?

testIfThere=$(ls /home/Idk/some/file)
if [ -z $testIfThere ]; then
false
else
what do you want to do?
fi

[vast kiln]

"what do you want to do?"
exactly, problem is unclear.

[sage hornet]

do you mean read from the file?

[lusty mural]

touch -m -d -@"1" '/mnt/u/filename.ext'
jq -r .files[0].DateModified,.files[0].FileName '/mnt/c/Users/username/Downloads/PHOTO_INFO.json'
output:
1598544616000
IMG-20200827-WA0011.jpeg

so basically, take the lines from 2) and substitute it into 1)
touch -m -d -@"1598544616" '/mnt/u/IMG-20200827-WA0011.jpeg'

minus 3 0's from this time 1598544616000 > 1598544616 (10 digit number only)

Actually better yet, how can I search for a filename or path and then have it automatically get the date modified from the json ?

this is a more updated question

instead of searching by index in [#] number, it would be easier if I search by name and it gives the datemodified field

look for files matching this path

[sage hornet]

oof that sounds way more challenging to get a human readable date modified

wait

does the JSON match ls -lt

ls can list by date modified - does the JSON match ls -lt?

problem: if you update name, then the file might update date modified

unless you mount your root file system as noatime or whatever before modifying name, or using a tool that doesn't update date modified

or is just searching with ls -lt enough?

this is what the output of ls -lt may look like

[lusty mural]

is this used with wsl2 on windows ?

[sage hornet]

I've hardly ever used Windows so you'll have to find that out

[lusty mural]

there's 586 files to change the dates

[lusty mural]

Im using windows subsystem for linux so it seems like it can do much of what linux can on windows

[sage hornet]

disgusting limitation

unless that wasn't a typo

[sage hornet]

why do you want to change the dates?

also how would you force it not to update to today's date?

[lusty mural]

samsung smart switch backup on PC doesn't retain the android phone's original date modified, it makes all the files the date of backup on PC. The original date modified as in android was recorded in the PHOTO_INFO.json file hence why I want to revert it back to original

[sage hornet]

oh

[lusty mural]

by using touch command to change only the date modified

[lusty mural]

unless I can test something where, if I restore part of the backup -- whatsapp images back into another android phone and then backup that specific part of the phone with linux will it retain the original timestamp ?

[sage hornet]

probably won't get the OG time stamp unless it were maybe copied directly from the older Android phone

[sage hornet]

sounds tough

I'd probably have to have that JSON myself and try to script something up

[lusty mural]

the problem is that the whatsapp files don't exist on the phone anymore, it was backed up to PC with it's json file and then the pictures were deleted in 2021, so the pictures are not on the phone with the original dates.

[lusty mural]

i can send it to

[sage hornet]

oh boy, single line

that'd sure take some processing to put the awk command to work

maybe awk gsub of , as field separator

sorry, maybe I'll try once I get my clipboard history program all integrated like an app

[lusty mural]

okay

I'm going to try to restore backup to this s21 for a small sample of files and see what changes

There has to be a faster way to get those timestamps and filenames

as u can see everything above the blue box, is what i changed manually from the json file and wsl2, and all the highlighted files are all backed up from samsung smart switch back in 2021

all having the same dates

[lusty mural]

u can download the .json file

[sage hornet]

after I tackle a bunch of my own things, sure

[lusty mural]

okay. FYi, I can import the .json file into exel. Can I do something with excel ?

[lusty mural]

okay weird, samsung smart switch said that there are no files in the backup. It didn't recognize the backup (even though its from my brother's PC). Maybe he didn't back it up properly

[lusty mural]

solved it using excel lol

using this kind of syntax:

="touch -m -d -@"&CHAR(34)&LEFT([@[Column1.DateModified]],LEN([@[Column1.DateModified]])-3)&CHAR(34)&" "&CHAR(34)&[@[Column1.FileName]]&CHAR(34)

imported the PHOTO_INFO.json file into power data query and then formatted it as a table, then under Column1.FilePath, I filtered to /mnt/sdcard/WhatsApp/Media/WhatsApp Images to show only whatsapp files, then i made a new column with the above syntax and just copy and paste all the rows into wsl2 linux and then it updated all the date modified of all the files

Although I'm not really sure why there are duplicate entries for each touch command

Here is what the excel table looks like:

[sage hornet]

so you figured it out?