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sftp_write_sliding.c
/*
 * Sample showing how to do SFTP non-blocking write transfers.
 *
 * The sample code has default values for host name, user name, password
 * and path to copy, but you can specify them on the command line like:
 *
 * "sftp 192.168.0.1 user password sftp_write_nonblock.c /tmp/sftp_write_nonblock.c"
 */ 
 
#include "libssh2_config.h"
#include <libssh2.h>
#include <libssh2_sftp.h>
 
#ifdef HAVE_WINSOCK2_H
#include <winsock2.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
 
#include <sys/types.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>
#include <time.h>
 
static int waitsocket(int socket_fd, LIBSSH2_SESSION *session)
{
    struct timeval timeout;
    int rc;
    fd_set fd;
    fd_set *writefd = NULL;
    fd_set *readfd = NULL;
    int dir;
 
    timeout.tv_sec = 10;
    timeout.tv_usec = 0;
 
    FD_ZERO(&fd);
 
    FD_SET(socket_fd, &fd);
 
    /* now make sure we wait in the correct direction */ 
    dir = libssh2_session_block_directions(session);

 
    if(dir & LIBSSH2_SESSION_BLOCK_INBOUND)
        readfd = &fd;
 
    if(dir & LIBSSH2_SESSION_BLOCK_OUTBOUND)
        writefd = &fd;
 
    rc = select(socket_fd + 1, readfd, writefd, NULL, &timeout);
 
    return rc;
}
 
int main(int argc, char *argv[])
{
    unsigned long hostaddr;
    int sock, i, auth_pw = 1;
    struct sockaddr_in sin;
    const char *fingerprint;
    LIBSSH2_SESSION *session;
    const char *username="username";
    const char *password="password";
    const char *loclfile="sftp_write_nonblock.c";
    const char *sftppath="/tmp/sftp_write_nonblock.c";
    int rc;
    FILE *local;
    LIBSSH2_SFTP *sftp_session;
    LIBSSH2_SFTP_HANDLE *sftp_handle;
    char mem[1024 * 1000];
    size_t nread;
    size_t memuse;
    time_t start;
    long total = 0;
    int duration;
 
#ifdef WIN32
    WSADATA wsadata;
    int err;
 
    err = WSAStartup(MAKEWORD(2,0), &wsadata);
    if (err != 0) {
        fprintf(stderr, "WSAStartup failed with error: %d\n", err);
        return 1;
    }
#endif
 
    if (argc > 1) {
        hostaddr = inet_addr(argv[1]);
    } else {
        hostaddr = htonl(0x7F000001);
    }
 
    if (argc > 2) {
        username = argv[2];
    }
    if (argc > 3) {
        password = argv[3];
    }
    if (argc > 4) {
        loclfile = argv[4];
    }
    if (argc > 5) {
        sftppath = argv[5];
    }
 
    rc = libssh2_init (0);

    if (rc != 0) {
        fprintf (stderr, "libssh2 initialization failed (%d)\n", rc);
        return 1;
    }
 
    local = fopen(loclfile, "rb");
    if (!local) {
        fprintf(stderr, "Can't open local file %s\n", loclfile);
        return -1;
    }
 
    /*
     * The application code is responsible for creating the socket
     * and establishing the connection
     */ 
    sock = socket(AF_INET, SOCK_STREAM, 0);
 
    sin.sin_family = AF_INET;
    sin.sin_port = htons(22);
    sin.sin_addr.s_addr = hostaddr;
    if (connect(sock, (struct sockaddr*)(&sin),
                sizeof(struct sockaddr_in)) != 0) {
        fprintf(stderr, "failed to connect!\n");
        return -1;
    }
 
    /* Create a session instance
        */ 
    session = libssh2_session_init();

    if (!session)
        return -1;
 
    /* Since we have set non-blocking, tell libssh2 we are non-blocking */ 
    libssh2_session_set_blocking(session, 0);

 
    /* ... start it up. This will trade welcome banners, exchange keys,
        * and setup crypto, compression, and MAC layers
        */ 
    while ((rc = libssh2_session_handshake(session, sock))

           == LIBSSH2_ERROR_EAGAIN);
    if (rc) {
        fprintf(stderr, "Failure establishing SSH session: %d\n", rc);
        return -1;
    }
 
    /* At this point we havn't yet authenticated.  The first thing to do is
     * check the hostkey's fingerprint against our known hosts Your app may
     * have it hard coded, may go to a file, may present it to the user,
     * that's your call
     */ 
    fingerprint = libssh2_hostkey_hash(session, LIBSSH2_HOSTKEY_HASH_SHA1);

    fprintf(stderr, "Fingerprint: ");
    for(i = 0; i < 20; i++) {
        fprintf(stderr, "%02X ", (unsigned char)fingerprint[i]);
    }
    fprintf(stderr, "\n");
 
    if (auth_pw) {
        /* We could authenticate via password */ 
        while ((rc = libssh2_userauth_password(session, username, password)) ==

               LIBSSH2_ERROR_EAGAIN);
        if (rc) {
            fprintf(stderr, "Authentication by password failed.\n");
            goto shutdown;
        }
    } else {
        /* Or by public key */ 
        while ((rc = libssh2_userauth_publickey_fromfile(session, username,

                                                         "/home/username/.ssh/id_rsa.pub",
                                                         "/home/username/.ssh/id_rsa",
                                                         password)) ==
               LIBSSH2_ERROR_EAGAIN);
    if (rc) {
            fprintf(stderr, "\tAuthentication by public key failed\n");
            goto shutdown;
        }
    }
 
    fprintf(stderr, "libssh2_sftp_init()!\n");

    do {
        sftp_session = libssh2_sftp_init(session);

 
        if (!sftp_session &&
            (libssh2_session_last_errno(session) != LIBSSH2_ERROR_EAGAIN)) {

            fprintf(stderr, "Unable to init SFTP session\n");
            goto shutdown;
        }
    } while (!sftp_session);
 
    fprintf(stderr, "libssh2_sftp_open()!\n");

    /* Request a file via SFTP */ 
    do {
        sftp_handle =
        libssh2_sftp_open(sftp_session, sftppath,

                          LIBSSH2_FXF_WRITE|LIBSSH2_FXF_CREAT|LIBSSH2_FXF_TRUNC,
                          LIBSSH2_SFTP_S_IRUSR|LIBSSH2_SFTP_S_IWUSR|
                          LIBSSH2_SFTP_S_IRGRP|LIBSSH2_SFTP_S_IROTH);
 
        if (!sftp_handle &&
            (libssh2_session_last_errno(session) != LIBSSH2_ERROR_EAGAIN)) {

            fprintf(stderr, "Unable to open file with SFTP\n");
            goto shutdown;
        }
    } while (!sftp_handle);
 
    fprintf(stderr, "libssh2_sftp_open() is done, now send data!\n");

 
    start = time(NULL);
 
    memuse = 0; /* it starts blank */ 
    do {
        nread = fread(&mem[memuse], 1, sizeof(mem)-memuse, local);
        if (nread <= 0) {
            /* end of file */ 
            if (memuse > 0)
                /* the previous sending is not finished */ 
                nread = 0;
            else
                break;
        }
        memuse += nread;
        total += nread;
 
        /* write data in a loop until we block */ 
        while ((rc = libssh2_sftp_write(sftp_handle, mem, memuse)) ==

               LIBSSH2_ERROR_EAGAIN) {
            waitsocket(sock, session);
        }
        if(rc < 0)
            break;
 
        if(memuse - rc) {
            /* make room for more data at the end of the buffer */ 
            memmove(&mem[0], &mem[rc], memuse - rc);
            memuse -= rc;
        }
        else
            /* 'mem' was consumed fully */ 
            memuse = 0;
 
    } while (rc > 0);
 
    duration = (int)(time(NULL)-start);
 
    fprintf(stderr, "%ld bytes in %d seconds makes %.1f bytes/sec\n",
           total, duration, total/(double)duration);
 
 
    fclose(local);
    libssh2_sftp_close(sftp_handle);

    libssh2_sftp_shutdown(sftp_session);

 
shutdown:
 
    while (libssh2_session_disconnect(session, "Normal Shutdown, Thank you for playing")

           == LIBSSH2_ERROR_EAGAIN);
    libssh2_session_free(session);

 
#ifdef WIN32
    closesocket(sock);
#else
    close(sock);
#endif
    fprintf(stderr, "all done\n");
 
    libssh2_exit();

 
    return 0;
}
All Examples
direct_tcpip.c
scp.c
scp_nonblock.c
scp_write.c
scp_write_nonblock.c
sftp.c
sftp_RW_nonblock.c
sftp_append.c
sftp_mkdir.c
sftp_mkdir_nonblock.c
sftp_nonblock.c
sftp_write.c
sftp_write_nonblock.c
sftp_write_sliding.c
sftpdir.c
sftpdir_nonblock.c
ssh2.c
ssh2_agent.c
ssh2_echo.c
ssh2_exec.c
subsystem_netconf.c
tcpip-forward.c
x11.c

You'll also find all examples in the distribution archive, in the examples/simple directory.