diff options
Diffstat (limited to 'client.c')
-rw-r--r-- | client.c | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/client.c b/client.c new file mode 100644 index 0000000..591d030 --- /dev/null +++ b/client.c @@ -0,0 +1,100 @@ +/* +** client.c -- a stream socket client demo +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include <netdb.h> +#include <sys/types.h> +#include <netinet/in.h> +#include <sys/socket.h> + +#include <arpa/inet.h> + +#define PORT "3490" // the port client will be connecting to + +#define MAXDATASIZE 100 // max number of bytes we can get at once + +// get sockaddr, IPv4 or IPv6: +void *get_in_addr(struct sockaddr *sa) +{ + if (sa->sa_family == AF_INET) { + return &(((struct sockaddr_in*)sa)->sin_addr); + } + + return &(((struct sockaddr_in6*)sa)->sin6_addr); +} + +int main(int argc, char *argv[]) +{ + int sockfd, numbytesrecv, numbytessent; + char buf[MAXDATASIZE]; + struct addrinfo hints, *servinfo, *p; + int rv; + char s[INET6_ADDRSTRLEN]; + + if (argc != 3) { + fprintf(stderr,"usage: client hostname\n"); + exit(1); + } + + memset(&hints, 0, sizeof hints); + hints.ai_family = AF_INET; // only IPv4 + hints.ai_socktype = SOCK_STREAM; + + if ((rv = getaddrinfo(argv[2], PORT, &hints, &servinfo)) != 0) { + fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv)); + return 1; + } + + // loop through all the results and connect to the first we can + for(p = servinfo; p != NULL; p = p->ai_next) { + if ((sockfd = socket(p->ai_family, p->ai_socktype, + p->ai_protocol)) == -1) { + perror("client: socket"); + continue; + } + + if (connect(sockfd, p->ai_addr, p->ai_addrlen) == -1) { + close(sockfd); + perror("client: connect"); + continue; + } + + break; + } + + if (p == NULL) { + fprintf(stderr, "client: failed to connect\n"); + return 2; + } + + inet_ntop(p->ai_family, get_in_addr((struct sockaddr *)p->ai_addr), + s, sizeof s); + printf("client: connecting to %s\n", s); + + freeaddrinfo(servinfo); // all done with this structure + + if ((numbytesrecv = recv(sockfd, buf, MAXDATASIZE-1, 0)) == -1) { + perror("recv"); + exit(1); + } + + buf[numbytesrecv] = '\0'; + + printf("client: received '%s'\n",buf); + + if ((numbytessent = send(sockfd, "Welcome", 7, 0)) == -1) { + perror("send"); + exit(1); + } + + buf[numbytessent] = '\0'; + + close(sockfd); + + return 0; +}
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