Visit Our UNIX and Linux User Community


Building JSON command with bash script


 
Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Building JSON command with bash script
# 36  
Old 09-26-2019
Quote:
Originally Posted by psysc0rpi0n
Ok, I'm going to try your examples. This is not trivial for a starter. I've just been reading but not practicing much, so this is not clear at first sight!

--- Post updated at 10:02 PM ---



I don't fully understand what you mean by:


and
.

I need to read about expansions!
Fortunately this stuff is pretty well documented. I'd start with Shell Expansions, it's probably best while reading this to have a shell handy and try out the different expansions/substitutions mentioned with something like the pparm script posted above. Ensure you understand why they shell works the way it does.

For example word splitting occurs before pathname expansion, so when a file containing white space is expanded it wont be split.
Parameter and variable expansion occurs before word splitting so variables with white spaces are split:

Code:
$ ls
 jason_expand   pparm  'test with space'
$ ./pparm test*
Param 1: test with space
$ VAR="test with space"
$ ./pparm $VAR
Param 1: test
Param 2: with
Param 3: space
$ VAR=test
$ ./pparm ${VAR}*
<work thru the manual and decide what will happen here before trying it>


Last edited by Chubler_XL; 09-26-2019 at 10:04 PM..
These 2 Users Gave Thanks to Chubler_XL For This Post:
# 37  
Old 09-28-2019
Hello peeps...

I've been changing my script in several ways until I'm good with it.

I'm now trying to run a command depending on the value of a variable but this is not working.
The code that is not working is:

Code:
[ "$used_net" == "testnet" ] && btc_dec=$(bitcoin-cli -testnet getbalance)\
                             || btc_dec=$(bitcoin-cli getbalance)

I want to run one of those 2 commands depending on $used_net variable value! The thing is that no matter the value of $used_net, the issued command is always the one after '||'. What am I doing wrong?

Thanks
Psy
# 38  
Old 09-29-2019
Your code is correct and works here as you described it should. So I assume the variable $used_net never is set to the correct "testnet" value.

Check the variable value directly before the shown command.

Another variant to run it:

Code:
[ "$used_net" == "testnet" ] && btcopt="-testnet" || btcopt=
btc_dec=$(bitcoin-cli $btcopt getbalance)


Last edited by stomp; 09-29-2019 at 07:17 AM..
# 39  
Old 09-30-2019
Quote:
Originally Posted by stomp
Your code is correct and works here as you described it should. So I assume the variable $used_net never is set to the correct "testnet" value.

Check the variable value directly before the shown command.

Another variant to run it:

Code:
[ "$used_net" == "testnet" ] && btcopt="-testnet" || btcopt=
btc_dec=$(bitcoin-cli $btcopt getbalance)

Ok, I'll try that later today.

You want to explain how bash processes 2 variable atributions within the same line of code? Probably following some rule like left to right or right to left. But what is the return value of a successeful variable attribution (which I think will be the value assigned to 'btc_opt') in case of 'test' go false?
# 40  
Old 09-30-2019
Quote:
You want to explain how bash processes 2 variable atributions within the same line of code?
It's nearly the same code as yours: If $used_net is "testnet" set btcopts to "-testnet" otherwise set to empty value. A shorthand if-construct.

The return value of a variable assignment is always 0 - unless the command produces a syntax error.
This User Gave Thanks to stomp For This Post:
# 41  
Old 09-30-2019
For readability and later extend-ability i'd advocate an if then else construct:

Code:
if [ "$used_net" == "testnet" ] 
then
    btc_dec=$(bitcoin-cli -testnet getbalance)
else
    btc_dec=$(bitcoin-cli getbalance)
fi

Or a case statement:
Code:
case "$used_net" in
     testnet) btc_dec=$(bitcoin-cli -testnet getbalance) ;;
           *) btc_dec=$(bitcoin-cli getbalance)
esac

# 42  
Old 10-01-2019
Hello.

Yesterday I couldn't test the code. I was too tired and didn't even came to my laptop.

Today I tested it and the variable "$used_net" is correctly set! I echo'ed it right before testing it with 'test' as I posted in my post #37.

But I might have seen the wrong problem. I mean, the problem is not that it's not issuing the correct command as I said. I'm sorry for messing this. The problem is rather that both commans are buing issued!

Example:
Code:
send_multiple_payment(){
   eval_send_amount
   mk_json_object_one_val "$btc_amount_dec" "${addr_arr[@]}"
   mk_json_lst_one_val "${addr_arr[@]}"
   echo "\$used_net is: $used_net"
   [ "$used_net" == "testnet" ] ||  echo "bitcoin-cli -testnet sendmany \"\" {$pairs} 6 Payments [$items] true 6 CONSERVATIVE"\
                                &&  echo "bitcoin-cli sendmany \"\" {$pairs} 6 Payments [$items] true 6 CONSERVATIVE"
   #echo "TxID: $1"
 }

This is the problematic function, which is being called like:

Code:
LC_NUMERIC=C
check_args_count "$@"
process_args "$@"
load_addr_data
send_multiple_payment

The result is:
Code:
$ ./auto_trbtc.sh -m -a addr_lst.dat
2 addresses sucessefuly loaded.

0.00256372
$used_net is: mainnet
bitcoin-cli -testnet sendmany "" {"n1yswZYByRv3okGDHs1oDaevq8gsDaYZzC":"0.00256372","2NFafKRugHFdYEib7xVfkT6bvtkUKK8oShZ":"0.00256372"} 6 Payments ["n1yswZYByRv3okGDHs1oDaevq8gsDaYZzC","2NFafKRugHFdYEib7xVfkT6bvtkUKK8oShZ"] true 6 CONSERVATIVE
bitcoin-cli sendmany "" {"n1yswZYByRv3okGDHs1oDaevq8gsDaYZzC":"0.00256372","2NFafKRugHFdYEib7xVfkT6bvtkUKK8oShZ":"0.00256372"} 6 Payments ["n1yswZYByRv3okGDHs1oDaevq8gsDaYZzC","2NFafKRugHFdYEib7xVfkT6bvtkUKK8oShZ"] true 6 CONSERVATIVE

When the expected is only:
Quote:
bitcoin-cli sendmany "" {"n1yswZYByRv3okGDHs1oDaevq8gsDaYZzC":"0.00256372","2NFafKRugHFdYEib7xVfkT6bvtkUKK8oShZ":"0.00256372 "} 6 Payments ["n1yswZYByRv3okGDHs1oDaevq8gsDaYZzC","2NFafKRugHFdYEib7xVfkT6bvtkUKK8oShZ"] true 6 CONSERVATIVE

edited;
One extra question:
The 'test' program uses && for true and || for false, right? Does it matters the order we place the code to be executed after the && or the || ? I mean, Does 'test' knows that && is always for true and || is always for false no matter which comes first?

edited 2;
In the meantime I did my test and answered myself:

Code:
#!/bin/bash

 test_str="trrue"

 [ "$test_str" == "trrue" ] && echo "true1" || echo "false2"
 [ "$test_str" == "trrue" ] || echo "true1" && echo "false2"

Code:
true1
false2


Last edited by psysc0rpi0n; 10-01-2019 at 07:21 PM..

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

How to convert any shell command output to JSON format?

Hi All, I am new to shell scripting, Need your help in creating a shell script which converts any unix command output to JSON format output. example: sample df -h command ouput : Filesystem size used avail capacity Mounted /dev/dsk/c1t0d0s0 8.1G 4.0G 4.0G 50% /... (13 Replies)
Discussion started by: balu1234
13 Replies

2. Shell Programming and Scripting

Fun with terminal plotting JSON data at the command line

One of the great thing about unix is the ability to pipe multiple programs together to manipulate data. Plain, unstructured text is the most common type of data that is passed between programs, but these days JSON is becoming more popular. I thought it would be fun to pipe together some command... (1 Reply)
Discussion started by: kbrazil
1 Replies

3. Shell Programming and Scripting

JSON structure to table form in awk, bash

Hello guys, I want to parse a JSON file in order to get the data in a table form. My JSON file is like this: { "document":{ "page": }, { "column": } ] }, { ... (6 Replies)
Discussion started by: Gescad
6 Replies

4. UNIX for Beginners Questions & Answers

Json field grap via shell script/awk

i have a json data that looks like this: { "ip": "16.66.35.10", "hostname": "No Hostname", "city": "Stepney", "region": "England", "country": "GB", "loc": "51.57,-0.0333", "org": "AS6871 British Telecommunications PLC", "postal": "E1" } im looking for a way to assign... (9 Replies)
Discussion started by: SkySmart
9 Replies

5. Shell Programming and Scripting

Parsing and Editing a json file with bash script

I am trying to automate editing of a json file using bash script. The file I initially receive is { "appMap": { "URL1": { "name": "a" }, "URL2": { "name": "b" }, "URL3": { "name": "c" }, } WHat I would like to do is replace... (5 Replies)
Discussion started by: Junaid Subhani
5 Replies

6. Shell Programming and Scripting

UNIX or Perl script to convert JSON to CSV

Is there a Unix or Perl script that converts JSON files to CSV or tab delimited format? We are running AIX 6.1. Thanks in advance! (1 Reply)
Discussion started by: warpmail
1 Replies

7. Shell Programming and Scripting

Bash script - cygwin (powershell?) pull from GitHub API Parse JSON

All, Have a weird issue where i need to generate a report from GitHub monthly detailing user accounts and the last time they logged in. I'm using a windows box to do this (work issued) and would like to know if anyone has any experience scripting for GitAPI using windows / cygwin / powershell?... (9 Replies)
Discussion started by: ChocoTaco
9 Replies

8. Shell Programming and Scripting

How to define a variable in a BASH script by using a JSON file online?

Hello, I would like to modify an existing script of mine that uses a manually defined "MCVERSION" variable and make it define that variable instead based on this JSON file stored online: https://s3.amazonaws.com/Minecraft.Download/versions/versions.json Within that JSON, I 'm looking for... (4 Replies)
Discussion started by: nbsparks
4 Replies

9. Shell Programming and Scripting

BASH SCRIPT of LS command

I need help in writing a BASH SCRIPT of ls command. for example: $ ./do_ls.sh files f1.txt f2.jpeg f3.doc $ ./do_ls.sh dirs folder1 folder2 folder3 My attempt: #!/bin/bash # if test $# -d file then echo $dirs else (3 Replies)
Discussion started by: above8k
3 Replies

10. Shell Programming and Scripting

Building command line parameters of arbitrary length

I couldn't find an existing thread that addressed this question, so hopefully this isn't redundant with anything previously posted. Here goes: I am writing a C-Shell script that runs a program that takes an arbitrary number of parameters: myprog -a file1 \ -b file2 \ -c file3 ... \ -n... (2 Replies)
Discussion started by: cmcnorgan
2 Replies

Featured Tech Videos