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/*
* This file is in the public domain.
* Author: Ben Fuller
*
* Basic netcat-like utility to create a connection on the specified
* address and port, using stdin and stdout.
*
*/
#include <stdio.h>
#include <errno.h>
#include <poll.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>
#define BUF_LEN 1024
void usage(const char *);
int sock_write(int, char *, size_t);
int sock_read(int);
int main(int argc, char *argv[]) {
int s, sfd = -1;
struct addrinfo hints, *result, *rp;
if (argc < 3) {
usage(argv[0]);
}
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE;
hints.ai_protocol = 0;
s = getaddrinfo(argv[1], argv[2], &hints, &result);
if (s != 0) {
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(s));
return 1;
}
for (rp = result; rp != NULL; rp = rp->ai_next) {
sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
if (sfd == -1)
continue;
if (connect(sfd, rp->ai_addr, rp->ai_addrlen) == 0)
break;
if (close(sfd) == -1) {
perror("close");
return 1;
}
}
freeaddrinfo(result);
if (rp == NULL) {
fprintf(stderr, "connection refused\n");
return 1;
}
int pollret;
struct pollfd fds[2];
fds[0].fd = 0;
fds[0].events = POLLIN;
fds[1].fd = sfd;
fds[1].events = POLLIN | POLLWRBAND;
char *line = NULL;
size_t linelen = 0;
while (1) {
pollret = poll(fds, 2, -1);
if (pollret <= 0) {
if (errno == EAGAIN)
continue;
/*if (pollret == 0)
fprintf(stderr, "timed out\n");*/
perror("poll");
free(line);
return 1;
}
if (fds[0].revents & POLLIN) {
ssize_t n;
if ((n = getline(&line, &linelen, stdin)) == -1) {
break;
}
if (sock_write(sfd, line, (size_t)n) != 0) {
free(line);
return 1;
}
}
if (fds[1].revents & POLLIN) {
int rec = sock_read(sfd);
if (rec < 0) {
free(line);
return 1;
} else if (rec == 0) {
break;
}
}
fds[0].revents = 0;
fds[1].revents = 0;
}
free(line);
if (close(sfd) == -1) {
perror("close");
return 1;
}
return 0;
}
void usage(const char *argv0){
fprintf(stderr, "usage: %s host port\n", argv0);
exit(1);
}
int sock_write(int sfd, char *msg, size_t len){
ssize_t ret;
ret = send(sfd, msg, len, 0);
if (ret != (ssize_t) len) {
perror("sock_write");
return 1;
}
return 0;
}
int sock_read(int sfd){
char buff[BUF_LEN] = {'\0'};
ssize_t ret = recv(sfd, buff, BUF_LEN, 0);
if (ret < 0) {
perror("sock_read");
return -1;
}
if (ret == 0)
return 0;
write(1, buff, ret);
return 1;
}
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