Extract ID from React Request

Task

Implement the function get_id.

• Write a function that extracts the ID from a react request path
• The path format is /react?user=<username>&message=<reaction>&id=<id>
• Return an interior pointer to the ID string within the original string
• You should modify the string by replacing any character after the ID (space, &, etc.) with \0
• If there is no id= parameter, return NULL

Function Signature

// Given a react request path, return a pointer to the ID string (or NULL if not found)
char* get_id(char* react_request);

Notes

• Find id= in the string
• The ID starts immediately after id=
• The ID ends at a space, &, or end of string
• Replace the terminating character with \0 (if it’s not already end of string)
• Return a pointer to the start of the ID (an interior pointer into the original string)
• If there is no id= in the path, return NULL
• The ID is returned as a string (you don’t need to convert to integer)
• strstr may be a helpful function to find substrings

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Example

Input	Output
/react?user=aaron&message=👍&id=5	5
/react?user=joe&message=cool&id=123	123
/react?user=alice&id=7&message=nice	7
/react?user=bob&message=wow&id=42 HTTP/1.1	42
/post?user=joe&message=hi	NULL

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Code

#include <stddef.h>
#include <stdio.h>
#include <string.h>
 
char* get_id(char* react_request)
{
    char* id = strstr(react_request, "id=");
    if(id == NULL){return NULL;}
    char* end = strstr(id + 3, " ");
    if (end == NULL){
        end = strstr(id + 3, "&");
    }
    if (end != NULL){
        *end = 0;
    }
    return id + 3;
}