Parse curl response with sed

bash sed regular-expression curl json

7,125

Solution 1

I would use command substitution instead of piping. On a Linux machine, I would use:

curl "http://my.api.com?query=$(curl https://api.ipify.org?format=json | grep -oP 'ip":"\K[0-9.]+')"

And on a machine that doesn't have GNU tools (e.g. macOS), one of:

curl "http://my.api.com?query=$(curl https://api.ipify.org?format=json | sed -E 's/.*ip":"([0-9.]+).*/\1/')"

Or even

curl "http://my.api.com?query=$(curl https://api.ipify.org?format=json 2>/dev/null | tr -d '"' | sed 's/.*ip:\([0-9.]*\).*/\1/')"

Solution 2

curl 'https://api.ipify.org?format=json' | jq -r '.ip'

This would use jq to extract the value associated with the top-level ip key in the JSON response from curl.

You could then use this to make your other curl call:

ipaddr=$( curl 'https://api.ipify.org?format=json' | jq -r '.ip' )
curl "http://my.api.com?query=$ipaddr"

Note also that URLs should always be quoted on the command line as they may contain ? and & and other characters that the shell would treat specially.

jq is available through Homebrew on macOS.

Or, you could, as pLumo suggests in comments, just don't request a JSON formatted response from api.ipfy.org:

ipaddr=( curl 'https://api.ipify.org' )
curl "http://my.api.com?query=$ipaddr"

7,125

Author by

Imnl

Updated on September 18, 2022

Comments

Imnl over 1 year
I'm trying to call a JSON API with the following curl command on macOS:
```
curl https://api.ipify.org?format=json
```
It returns something like this:
```
{"ip":"xxx.xxx.xxx.xxx"}
```
I would like to extract the IP address from this response and run another curl command with this.
```
curl https://api.ipify.org?format=json | curl http://my.api.com?query=<IP RESULT>
```
Some of my failed attempts involve piping the result through a sed command with a regular expression.
- terdon almost 4 years
  
  What operating system are you using? Do you have GNU tools?
- Imnl almost 4 years
  
  osx @terdon dont have preinstalled jq
- pLumo almost 4 years
  
  why don't you just use curl https://api.ipify.org which returns your IP directly... (just asking)
- Imnl almost 4 years
  
  @pLumo Agree 200%, im going still to leave the question because parsing a json response with unix default tools in an easy way stills has interest for me
- Kusalananda almost 4 years
  
  @Imnl Sorry, but what is "a bash tool"? If you mean you only want to use utilities built into bash, then you will find it extremely difficult to correctly parse JSON.
- Imnl almost 4 years
  
  @Kusalananda edited, i tried to say unix default tools.
- Kusalananda almost 4 years
  
  jq is the easiest, most robust, and stable way to parse JSON on macOS.