Socket programing Permission denied
c, sockets
Solution
Ports below 1024 are considered "privileged" and can only be bound to with an equally privileged user (read: root).
Anything above and including 1024 is "free to use" by anyone.
OT: you may know this already, but the port in your example is that for HTTP web servers. Anything listening to this port should speak HTTP, too. A simple "hello world" does not suffice. ;-)
Problem
Following code is TCP server program just send back “HELLO!!” to client. When I run server with port 80, bind() is returned `Permission denied`. Port 12345 is OK. How can I use port 80 for this server program? ``` #include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> int main(){ int sock0; struct sockaddr_in addr; struct sockaddr_in client; int len; int sock; char *message; message = "HELLO !!"; sock0 = socket(AF_INET,SOCK_STREAM,0); addr.sin_family = AF_INET; addr.sin_port = htons(80); inet_pton(AF_INET,"127.0.0.1",&addr,sizeof(addr)); bind(sock0,(struct sockaddr *)&addr,sizeof(addr)); perror("bind"); len = sizeof(client); sock = accept(sock0,(struct sockaddr *)&client,&len); perror("accept"); write(sock,message,sizeof(message)); perror("write"); close(sock); return 0; } ```