这段代码去掉libssh2_channel_request_pty
代码不加libssh2_channel_read ，libssh2_channel_read 当无数据读时，正常返回0.
代码加上libssh2_channel_request_pty 时，libssh2_channel_read 当无数据读时永久阻塞中，不返回0.一直返回 LIBSSH2_ERROR_EAGAIN
#include <iostream>
#include "CSecureX2.h"
#include "Ctstring.h"
#include "Properties.h"
#include "XFile.h"
#include <winsock2.h>
#include "CLog.h"
#ifdef _DEBUG
#pragma comment( lib, "libssh2d.lib")
#pragma comment( lib, "libcommd.lib")
#else
#pragma comment( lib, "libssh2.lib")
#pragma comment( lib, "libcomm.lib")
#endif
#pragma comment( lib, "ssleay32.lib")
#pragma comment( lib, "Shlwapi.lib")
#pragma comment(lib,"Ws2_32.lib ")
#pragma comment( lib, "libeay32.lib")
#pragma comment( lib, "ssleay32.lib")
#pragma comment( lib, "Crypt32.lib")
/*
* Sample showing how to use libssh2 to execute a command remotely.
*
* The sample code has fixed values for host name, user name, password
* and command to run.
*
* Run it like this:
*
* $ ./ssh2_exec 127.0.0.1 user password "uptime"
*
*/
#include <libssh2.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
#include <sys/types.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>
#pragma warning(disable:4996)
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[])
{
const char *hostname = "192.168.2.121";
const char *commandline = "uptime\n";
const char *username = "test";
const char *password = "test";
unsigned long hostaddr;
int sock;
struct sockaddr_in sin;
const char *fingerprint;
LIBSSH2_SESSION *session;
LIBSSH2_CHANNEL *channel;
int rc;
int exitcode;
char *exitsignal = (char *)"none";
int bytecount = 0;
size_t len;
LIBSSH2_KNOWNHOSTS *nh;
int type;
#ifdef WIN32
WSADATA wsadata;
WSAStartup(MAKEWORD(2, 0), &wsadata);
#endif
if (argc > 1)
/* must be ip address only */
hostname = argv[1];
if (argc > 2) {
username = argv[2];
}
if (argc > 3) {
password = argv[3];
}
if (argc > 4) {
commandline = argv[4];
}
rc = libssh2_init(0);
if (rc != 0) {
fprintf(stderr, "libssh2 initialization failed (%d)\n", rc);
return 1;
}
hostaddr = inet_addr(hostname);
/* Ultra basic "connect to port 22 on localhost"
* Your code is responsible for creating the socket 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;
/* tell libssh2 we want it all done 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;
}
while ((rc = libssh2_userauth_password(session, username, password)) ==
LIBSSH2_ERROR_EAGAIN);
if (rc) {
fprintf(stderr, "Authentication by password failed.\n");
goto shutdown;
}
/* Exec non-blocking on the remove host */
while ((channel = libssh2_channel_open_session(session)) == NULL &&
libssh2_session_last_error(session, NULL, NULL, 0) ==
LIBSSH2_ERROR_EAGAIN)
{
waitsocket(sock, session);
}
if (channel == NULL)
{
fprintf(stderr, "Error\n");
exit(1);
}
rc = 0;
while (rc = libssh2_channel_request_pty(channel, "ansi"))
{
waitsocket(sock, session);
}
if (rc != 0)
{
fprintf(stderr, "Error\n");
exit(1);
}
while ((rc = libssh2_channel_shell(channel))
== LIBSSH2_ERROR_EAGAIN)
{
waitsocket(sock, session);
}
if (rc != 0)
{
fprintf(stderr, "Error\n");
exit(1);
}
while ((rc = libssh2_channel_write(channel, commandline, strlen(commandline))) ==LIBSSH2_ERROR_EAGAIN)
{
waitsocket(sock, session);
}
if (rc < 0)
{
fprintf(stderr, "Error\n");
exit(1);
}
while ((rc = libssh2_channel_send_eof(channel)) == LIBSSH2_ERROR_EAGAIN)
{
waitsocket(sock, session);
}
if (rc < 0)
{
fprintf(stderr, "Error\n");
exit(1);
}
for (;; )
{
/* loop until we block */
int rc;
do
{
char buffer[0x4000];
rc = libssh2_channel_read(channel, buffer, sizeof(buffer));
if (rc > 0)
{
int i;
bytecount += rc;
fprintf(stderr, "We read:\n");
for (i = 0; i < rc; ++i)
fputc(buffer[i], stderr);
fprintf(stderr, "\n");
}
else {
if (rc != LIBSSH2_ERROR_EAGAIN)
/* no need to output this for the EAGAIN case */
fprintf(stderr, "libssh2_channel_read returned %d\n", rc);
}
} while (rc > 0);
/* this is due to blocking that would occur otherwise so we loop on
this condition */
if (rc == LIBSSH2_ERROR_EAGAIN)
{
waitsocket(sock, session);
}
else
break;
}
exitcode = 127;
while ((rc = libssh2_channel_close(channel)) == LIBSSH2_ERROR_EAGAIN)
waitsocket(sock, session);
if (rc == 0)
{
exitcode = libssh2_channel_get_exit_status(channel);
libssh2_channel_get_exit_signal(channel, &exitsignal,
NULL, NULL, NULL, NULL, NULL);
}
if (exitsignal)
fprintf(stderr, "\nGot signal: %s\n", exitsignal);
else
fprintf(stderr, "\nEXIT: %d bytecount: %d\n", exitcode, bytecount);
libssh2_channel_free(channel);
channel = NULL;
shutdown:
libssh2_session_disconnect(session,
"Normal Shutdown, Thank you for playing");
libssh2_session_free(session);
#ifdef WIN32
closesocket(sock);
#else
close(sock);
#endif
fprintf(stderr, "all done\n");
libssh2_exit();
return 0;
}
