87 lines
1.6 KiB
C
87 lines
1.6 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <strings.h>
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#include <sys/socket.h>
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#include <unistd.h>
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#include <netdb.h>
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#include <netinet/in.h>
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#define PORT 79
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void
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die(char *msg)
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{
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fprintf(stderr, "%s\n", msg);
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exit(1);
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}
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void
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read_server_response(int sockfd)
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{
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char c;
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while (read(sockfd, &c, 1)) {
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putchar(c);
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}
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}
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void
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finger_serverinfo(int sockfd)
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{
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write(sockfd, "\r\n", 2);
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read_server_response(sockfd);
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}
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void
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finger_user(int sockfd, char *username)
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{
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write(sockfd, username, strlen(username));
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write(sockfd, "\r\n", 2);
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read_server_response(sockfd);
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}
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int
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main(int argc, char *argv[])
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{
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/* argument handling */
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if (argc < 2 || argc > 3)
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die("usage: finger [user] server");
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char *servername, *user = NULL;
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if (argc == 2) {
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servername = argv[1];
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}
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else {
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servername = argv[2];
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user = argv[1];
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}
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/* setting up sockets and stuff */
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struct sockaddr_in servaddr;
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int sockfd = socket(AF_INET, SOCK_STREAM, 0);
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if (sockfd == -1)
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die("Couldn't create socket.");
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struct hostent *he = gethostbyname(servername);
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if (he == NULL)
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die("Couldn't get host.");
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bzero(&servaddr, sizeof(servaddr));
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servaddr.sin_family = AF_INET;
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servaddr.sin_addr = *((struct in_addr *) he->h_addr_list[0]);
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servaddr.sin_port = htons(PORT);
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if (connect(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr)) != 0)
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die("Couldn't connect to server.");
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if (user)
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finger_user(sockfd, user);
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else
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finger_serverinfo(sockfd);
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close(sockfd);
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}
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