Child Process aborted when parent is killed with SIGABRT linux C++ - c++

Question

I have a scenario where a spawned child process is killed when the parent is killed with SIGABRT. In my understanding, the child should continue to run. To mimic the actual code, I created two files presenting child and parent. The parent writes to a pipe and child reads from the read end (STDIN_FILENO).
parent code -> parent.cpp
#include <iostream>
#include <stdlib.h>
#include <string>
#include <unistd.h>
int main() {
int pipefd[2];
std::string message = "test\n";
if (pipe(pipefd) == -1) {
perror("pipe");
exit(EXIT_FAILURE);
}
int pid = fork();
if (0 == pid) {
std::cout << "Inside child process\n";
close(pipefd[1]);
char *args[] = {"./CHILD", NULL};
char *envp[] = {NULL};
if (dup2(pipefd[0], STDIN_FILENO) == -1) {
std::cout << "dup2 failed\n";
}
close(pipefd[0]);
close(pipefd[1]);
execve(args[0], args, envp);
} else {
close(pipefd[0]);
while (1) {
sleep(1);
std::cout << "parent writing -> " << message;
write(pipefd[1], message.c_str(), message.length());
}
}
return 0;
}
child code -> child.cpp
#include <iostream>
#include <string>
#include <unistd.h>
int main() {
std::string str;
char buf;
std::cout << "[child] started\n";
while (read(STDIN_FILENO, &buf, sizeof(buf)) > 0) {
if (buf != '\n')
str += buf;
else {
write(STDOUT_FILENO, str.c_str(), str.length());
str.clear();
write(STDOUT_FILENO, "\n", 1);
}
}
std::cout << "[child] Exiting the application\n";
return 0;
}
if the parent is killed with SIGABRT, the child also receives the same. When the pipe code is removed, the signal is not propagated.
Can you please provide some insight into it?