piping and redirecting weird result - shell

Considering 2 json files:
fileA.json:
{
"foo": "hey",
"bar": "ola"
}
fileB.json:
{
"foo": "hoy"
}
, executing:
% cat fileA.json fileB.json | json
returns
{
"foo": "hoy",
"bar": "ola"
}
Ok
--
Now why when redirecting stdout to fileB.json I get:
% cat fileA.json fileB.json | json > fileB.json
I get:
{
"foo": "hey",
"bar": "ola"
}
Ie: fileA.json ???
PS: json utility is here: http://trentm.com/json

The shell sets up output redirection, > fileB.json, so it opens and truncates fileB.json before cat has started reading from it. This causes cat to read an empty file. (It might even end up reading partially written output data.)
Never read from and write to the same file in a pipeline. Try something like > fileC.json instead.

Related

How to use sed command to replace value in json file

My json file looks like this:
"parameters": {
"$connections": {
"value": {
"azureblob": {
"connectionId": "/subscriptions/2b06d50xxxxxedd021/resourceGroups/Reource1005/providers/Microsoft.Web/connections/azureblob",
"connectionName": "azureblob",
"connectionProperties": {
"authentication": {
"type": "ManagedServiceIdentity"
}
},
"id": "/subscriptions/2b06d502-3axxxxxxedd021/providers/Microsoft.Web/locations/eastasia/managedApis/azureblob"
},
"office365": {
"connectionId": "/subscriptions/2b06d502xxxxxc8-5a8939edd021/resourceGroups/Reource1005/providers/Microsoft.Web/connections/office365",
"connectionName": "office365",
"id": "/subscriptions/2b06d50xxxxxx939edd021/providers/Microsoft.Web/locations/eastasia/managedApis/office365"
}
}
}
}
}
I want to use sed command to replace the string in connectionId, currently my script is as follows:
script: 'sed -e ''/connectionId/c\ \"connectionId\" : \"/subscriptions/2b06d50xxxxb-92c8-5a8939edd021/resourceGroups/Reourcetest/providers/Microsoft.Web/connections/azureblob\",'' "$(System.DefaultWorkingDirectory)/function-app-actions/templates/copycode.json"'
This script can replace the strings in both connectionIds in the json file with "Resourcetest", that's what I want to make the strings in the second connectionId replace with other values, how can I do that?
I'm new to sed commands, any insight is appreciated。
Edit:
I just want to replace "Resource1005" in both connectionId strings in the json file with "Resourcetest", but I need other content in the connectionIds string to keep the previous value
So my expected output should look like this:
"connectionId": "/subscriptions/2b06d502-3axxxx8939edd021/resourceGroups/Reourcetest/providers/Microsoft.Web/connections/azureblob"
"connectionId": "/subscriptions/2b06d502-3axxxx8939edd021/resourceGroups/Reourcetest/providers/Microsoft.Web/connections/office365"
If I use the script I mentioned above, it does replace the two Resource1005s, but the other values in the string are also replaced with the same (I just want to replace the Resource1005 value)
1st solution: With your shown samples and attempts, please try following GNU awk code. This will print only edited lines(as per shown samples) in output with substituting Resource1005 with Resourcetest in values.
awk -v RS='[[:space:]]+"connectionId": "[^"]*' '
RT{
sub(/\n+[[:space:]]+/,"",RT)
sub(/\/Resource1005\//,"/Resourcetest/",RT)
print RT
}
' Input_file
2nd solution: With sed you can try following sed code.
sed -nE 's/(^[[:space:]]+"connectionId": ".*)\/Resource1005\/(.*)/\1\/Resourcetest\/\2/p' Input_file
Common practice is to create template files and change them with sed or something else. Like this for example:
cat template.json
...
"office365": {
"connectionId": "__CONNECTIONID__",
"connectionName": "office365",
"id": "__ID__"
}
...
sed 's|__CONNECTIONID__|/some/path|; s|__ID__|/some/other/path|' template.json > new.json

Is there a way to instantiate key with JQ?

Is there a way for jq to instantiate a key to output?
Given:
{
"foo": "bizz",
"bar": "buzz",
"bat": [
"somestring"
]
}
I would like to do something like jq '. | {foobar.foo, foobar.bar}'
and have it output:
{
"foobar": {
"foo": "bizz",
"bar": "buzz"
}
}
without having to make the initial foobar dictionary.
Another possibility to consider:
{foobar: del(.bat)}
You don't have to "create a dictionary" first. Simply define your object's structure (.| is a redundant no-op, it can be left out):
jq '{ foobar: { foo, bar } }'

How to extract simple text and store into a file?

I'm writing a bash script for hetzner's cloud API, and I need to store the server's ID to a text file. After the command using it will output the below,
{
"server": {
"id": 12345678,
"name": "servertest-101",
"status": "initializing",
"created": "2020-09-18T09:22:21+00:00",
This is just a snippet, but that's from the first line of the response.
How can I extract and store that value?
The api returns in json format: You've not given much information but use jq to parse it:
$ cat myinput.json
{
"server": {
"id": 12345678,
"name": "servertest-101",
"status": "initializing",
"created": "2020-09-18T09:22:21+00:00"
}
}
$ jq -r .server.id myinput.json
12345678
redirect to a file:
$ jq -r .server.id myinput.json > myoutputfile
$ cat myoutputfile
12345678
You can pipe output of your command to process it further as this:
cat yourjson.json | grep -m 1 -E -o '\"id\": [0-9]+' | cut -d" " -f 2 > yourtextfile.txt
First, get your json content, then send it through the grep command that extracts only part "id": 1234567 using regular expression. Then pipe this result to cut command that splits it by a space and selects the second part, which is your value. Lastly, you redirect result of the job to the desired text file.
If you are sure that your value is going to always be the first number in the input, you can just simply select it by grep:
cat yourjson.json | grep -m 1 -E -o '[0-9]+' > output.txt

cannot call bash environment variable inside jq

In the below script, I am not able to successfully call the "repovar" variable in the jq command.
cat quayrepo.txt | while read line
do
export repovar="$line"
jq -r --arg repovar "$repovar" '.data.Layer| .Features[] | "\(.Name), \(.Version), $repovar"' severity.json > volume.csv
done
The script uses a text file to loop through the repo names
quayrepo.txt---> file has the list of names in this case the file has a value of "Reponame1"
sample input severity.json file:
{
"status": "scanned",
"data": {
"Layer": {
"IndexedByVersion": 3,
"Features": [
{
"Name": "elfutils",
"Version": "0.168-1",
"Vulnerabilities": [
{
"NamespaceName": "debian:9",
"Severity": "Medium",
"Name": "CVE-2016-2779"
}
]
}
]
}
}
}
desired output:
elfutils, 0.168-1, Medium, Reponame1
Required output: I need to retrieve the value of my environment variable as the last column in my output csv file
You need to surround $repovar with parenthesis, as the other values
repovar='qweqe'; jq -r --arg repovar "$repovar" '.data.Layer| .Features[] | "\(.Name), \(.Version), \($repovar)"' tmp.json
Result:
elfutils, 0.168-1, qweqe
There's no need for the export.
#!/usr/bin/env bash
while read line
do
jq -r --arg repovar "$line" '.data.Layer.Features[] | .Name + ", " + .Version + ", " + $repovar' severity.json
done < quayrepo.txt > volume.csv
with quayrepo.txt as
Reponame1
and severity.json as
{
"status": "scanned",
"data": {
"Layer": {
"IndexedByVersion": 3,
"Features": [
{
"Name": "elfutils",
"Version": "0.168-1",
"Vulnerabilities": [
{
"NamespaceName": "debian:9",
"Severity": "Medium",
"Name": "CVE-2016-2779"
}
]
}
]
}
}
}
produces volume.csv containing
elfutils, 0.168-1, Reponame1
To #peak's point, changing > to >> in ...severity.json >> volume.csv will create a multi-line csv instead of just overwriting until the last line
You don't need a while read loop in bash at all; jq itself can loop over your input lines, even when they aren't JSON, letting you run jq only once, not once per line in quayrepo.txt.
jq -rR --slurpfile inJson severity.json <quayrepo.txt >volume.csv '
($inJson[0].data.Layer | .Features[]) as $features |
[$features.Name, $features.Version, .] |
#csv
'
jq -R specifies raw input, letting jq directly read lines from quayrepo.txt into .
jq --slurpfile varname filename.json reads filename.json into an array of JSON objects parsed from that file. If the file contains only one object, one needs to refer to $varname[0] to refer to it.
#csv converts an array to a CSV output line, correctly handling data with embedded quotes or other oddities that require special processing.

Generate json file with formatting

I have a curl command which generates json output. I want to add a few characters in generated file to be able to process it further.
Command:
curl -sN --negotiate -u foo:bar "http://hostname/db/tbl_name/" >> db.json
This runs under a for loop which runs it for a db and tbl_name combination. Hence it ends up generating a number of json outputs(one for each table) concatenated together without any delimiter.
Output looks like :
{"columns":[{"name":"tbl_id","type":"varchar(50)"},{"name":"cret_timestmp","type":"timestamp"},{"name":"updt_timestmp","type":"timestamp"},{"name":"frst_nm","type":"varchar(50)"},{"name":"last_nm","type":"varchar(50)"},{"name":"acct_num","type":"varchar(15)"},{"name":"r_num","type":"varchar(15)"},{"name":"pid","type":"decimal(15,0)"},{"name":"ami_id","type":"varchar(30)"},{"name":"ssn","type":"varchar(9)"},{"name":"client_id","type":"varchar(30)"},{"name":"client_nm","type":"varchar(100)"},{"name":"info","type":"timestamp"},{"name":"rmx","type":"varchar(10)"},{"name":"id","type":"decimal(12,0)"},{"name":"ingest_timestamp","type":"string"},{"name":"incr_ingest_timestamp","type":"string"}],"database":"db_i","table":"db_tbl"}{"columns":[{"name":"key","type":"varchar(15)"},{"name":"foo_cd","type":"varchar(10)"},{"name":"foo_nm","type":"varchar(56)"},{"name":"tmc_regn_cd","type":"varchar(10)"},{"name":"tmc_mrkt_cd","type":"varchar(20)"},{"name":"mrkt_grp","type":"varchar(30)"},{"name":"ingest_timestamp","type":"string"},{"name":"incr_ingest_timestamp","type":"string"}],"database":"db_i","table":"ss_mv"}{"columns":[{"name":"bar_src_name","type":"string"},{"name":"bar_ent_name","type":"string"},{"name":"from_src","type":"string"},{"name":"reload","type":"string"},{"name":"column_mismatch","type":"string"},{"name":"xx_src_name","type":"string"},{"name":"xx_ent_name","type":"string"}],"database":"db_i","table":"test_table"}
Desired output is to start and end the output with []. Also I want to include "," between the end and beginning where column list starts.
So for ex: if the curl command runs against 3 tables as shown above, then the three generated jsons should be created like :
[{json1},{json2},{json3}]
Number 1,2,3 ...etc corresponds to different tables in curl command running in for loop against a particular db whose json should be created in one file but with desired format.
instead of what I'm currently getting :
{json1}{json2}{json3}
In the output pasted above, JSON 1 is :
{"columns":[{"name":"tbl_id","type":"varchar(50)"},{"name":"cret_timestmp","type":"timestamp"},{"name":"updt_timestmp","type":"timestamp"},{"name":"frst_nm","type":"varchar(50)"},{"name":"last_nm","type":"varchar(50)"},{"name":"acct_num","type":"varchar(15)"},{"name":"r_num","type":"varchar(15)"},{"name":"pid","type":"decimal(15,0)"},{"name":"ami_id","type":"varchar(30)"},{"name":"ssn","type":"varchar(9)"},{"name":"client_id","type":"varchar(30)"},{"name":"client_nm","type":"varchar(100)"},{"name":"info","type":"timestamp"},{"name":"rmx","type":"varchar(10)"},{"name":"id","type":"decimal(12,0)"},{"name":"ingest_timestamp","type":"string"},
{"name":"incr_ingest_timestamp","type":"string"}],"database":"db_i","table":"db_tbl"}
JSON 2 is :
{"columns":[{"name":"key","type":"varchar(15)"},{"name":"foo_cd","type":"varchar(10)"},{"name":"foo_nm","type":"varchar(56)"},{"name":"tmc_regn_cd","type":"varchar(10)"},{"name":"tmc_mrkt_cd","type":"varchar(20)"},{"name":"mrkt_grp","type":"varchar(30)"},{"name":"ingest_timestamp","type":"string"},{"name":"incr_ingest_timestamp","type":"string"}],"database":"db_i","table":"ss_mv"}
JSON 3 is :
{"columns":[{"name":"bar_src_name","type":"string"},{"name":"bar_ent_name","type":"string"},{"name":"from_src","type":"string"},{"name":"reload","type":"string"},{"name":"column_mismatch","type":"string"},{"name":"xx_src_name","type":"string"},{"name":"xx_ent_name","type":"string"}],"database":"db_i","table":"test_table"}
I hope the requirement is clear, thanks in advance, looking to achieve this via bash.
Use jq -s.
--slurp/-s: Instead of running the filter for each JSON object in the input, read the entire input stream into a large array
and run the filter just once.
Here's an example:
$ cat file.json
{ "key": "value1" }
{ "key": "value2" }
{ "key":
"value3"}{"key": "value4"}
$ jq -s < file.json
[
{
"key": "value1"
},
{
"key": "value2"
},
{
"key": "value3"
},
{
"key": "value4"
}
]
I'm not sure if I got it correctly, but I think you are looking for something like
echo "[$(cat *.json | paste -sd ',')]" > result.json
This works by creating a string that starts with [ and ends with ], and in the middle, there are the contents of the json files concatenated (cat) and separated by commas (with the help of paste). That string is echoed and written to a new file.
Presuming input in valid JSONL format (one JSON document per line of input), you can embed a Python script inside your bash script:
slurpjson_py='
import json, sys
json.dump([json.loads(line.strip()) for line in sys.stdin], sys.stdout, indent=4)
sys.stdout.write("\n")
'
slurpjson() { python -c "$slurpjson_py" "$#"; }
If called as:
slurpjson <<EOF
{ "first": "document", "starting": "here" }
{ "second": "document", "ending": "here" }
EOF
...output is correctly:
[
{
"starting": "here",
"first": "document"
},
{
"second": "document",
"ending": "here"
}
]
I managed to achieve this by running curl command and adding a "," with every line break using
sed 's/$/,/'
And then remove the last "," and added first and end [] using :
for i in *; do cat $i | sed '$ s/.$//' | awk '{print "["$0"]"}' > $json_dir/$i; done

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