httpfile.c

#include <assert.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <sys/stat.h>
#include <unistd.h>

#define STR "Hello tcp world\n"
#define pexit(x)                                \
        do {                                    \
                perror(x);                      \
                exit(EXIT_FAILURE);             \
        } while (0)

static struct sockaddr_in saddr;

int main(int argc, char **argv)
{
        int sock, clisock;

        if (argc < 2) {
                printf("Usage: %s FILE_TO_SERV [PORT]", argv[0]);
                exit(EXIT_FAILURE);
        }

        assert(argv[1]);

        sock = socket(AF_INET, SOCK_STREAM, 0);

        saddr.sin_family = AF_INET;
        saddr.sin_addr.s_addr = htonl(INADDR_ANY);
        if (argc == 3)
                saddr.sin_port = htons(atoi(argv[2]));
        else
                saddr.sin_port = htons(80);

        if (bind(sock, (struct sockaddr *)&saddr, sizeof(saddr)))
                pexit("bind");

        if (listen(sock, 10))
                pexit("listen");

        for (;;) {
                FILE *fp;
                struct stat s;
#define LBUFLEN 256
                char httpheader_buf[LBUFLEN];
                char linebuf[LBUFLEN];
                int filesiz;

                if ((clisock = accept(sock, NULL, NULL)) == -1) {
                        perror("accept");
                        continue;
                }
                puts("New connection");

                while (stat(argv[1], &s))
                        sleep(1);
                puts("Sending file contents");

                fp = fopen(argv[1], "r");
                if (!fp) {
                        perror("fopen");
                        continue;
                }

                fseek(fp, 0L, SEEK_END);
                filesiz = ftell(fp);
                fseek(fp, 0L, SEEK_SET);

                snprintf(httpheader_buf, LBUFLEN,
                        "HTTP/1.1 200 OK\r\n"
                        "Content-Type: text/html; charset=UTF-8\r\n"
                        "Content-Length: %d\r\n"
                        "Server: dummy\r\n"
                        "\r\n", filesiz);

                send(clisock, httpheader_buf, strlen(httpheader_buf), 0);

                do {
                        fgets(linebuf, LBUFLEN, fp);
                        send(clisock, linebuf, strlen(linebuf), 0);
                } while (!feof(fp));

                close(clisock);
                fclose(fp);
        }

        return 0;
}