problem with bash script for loop with rest api-CodePudding

I am trying to write a bash loop to retrieve a series of numbers using cURL, but I am having trouble understanding how to do it. The code below is an example of how I am trying to retrieve the first million digits of pi, where the API can only accept 1000 digits at a time.

for Numbers in {0..100000000000000..1000}
    do
    curl "https://api.pi.delivery/v1/pi?start=$Numbers&numberOfDigits=100&radix=10"
    echo $Numbers
    done

Additionally, I would like to write the returned values to a file called pi.txt instead of displaying them in the terminal. Should I use the >>pi.txt command in the terminal or within the script? Can someone help me correct this bash script?

and another problem i'm encountering is that when i go higher in range values for example first billion instead of million i get a 'invalid request: start' how can this be solved

the code above works with 1000000 but not when you increase the value

CodePudding user response：

If I use {0..100000000000000..1000}, I get:

bash: brace expansion: failed to allocate memory for 1215752193 elements

You can use

seq 0 1000 100000000000000 | while read Numbers
do
    …
done

instead, but you'll need a lot of patience.

CodePudding user response：

Give this a try:

#!/bin/bash

file_path="path/to/pi.txt"

for i in {0..1000000..1000}
do
    curl 'https://api.pi.delivery/v1/pi?start='"$i"'&numberOfDigits=1000'
    echo "$i"
done > "$file_path"

When you use single quotes around a string, it preserves its literal value, the difference from double quotes is the exception for the character $ amongst others.

This post describes this matter more deeply, referring to the Bash manual.