C语言实现ftp客户端

在VS2010新建win32控制台空项目，加入下面代码：

ftplib.h：

/***************************************************************************/
/*									   */
/* ftplib.h - header file for callable ftp access routines                 */
/* Copyright (C) 1996, 1997 Thomas Pfau, pfau@cnj.digex.net                */
/*	73 Catherine Street, South Bound Brook, NJ, 08880		   */
/*									   */
/* This library is free software; you can redistribute it and/or	   */
/* modify it under the terms of the GNU Library General Public		   */
/* License as published by the Free Software Foundation; either		   */
/* version 2 of the License, or (at your option) any later version.	   */
/* 									   */
/* This library is distributed in the hope that it will be useful,	   */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of	   */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU	   */
/* Library General Public License for more details.			   */
/* 									   */
/* You should have received a copy of the GNU Library General Public	   */
/* License along with this progam; if not, write to the			   */
/* Free Software Foundation, Inc., 59 Temple Place - Suite 330,		   */
/* Boston, MA 02111-1307, USA.						   */
/*									   */
/***************************************************************************/

#if !defined(__FTPLIB_H)
#define __FTPLIB_H

#if defined(__unix__) || defined(VMS)
#define GLOBALDEF
#define GLOBALREF extern
#elif defined(_WIN32)
#if defined BUILDING_LIBRARY
#define GLOBALDEF __declspec(dllexport)
#define GLOBALREF __declspec(dllexport)
#else
#define GLOBALREF __declspec(dllimport)
#endif
#endif

/* FtpAccess() type codes */
#define FTPLIB_DIR 1
#define FTPLIB_DIR_VERBOSE 2
#define FTPLIB_FILE_READ 3
#define FTPLIB_FILE_WRITE 4

/* FtpAccess() mode codes */
#define FTPLIB_ASCII 'A'
#define FTPLIB_IMAGE 'I'
#define FTPLIB_TEXT FTPLIB_ASCII
#define FTPLIB_BINARY FTPLIB_IMAGE

/* connection modes */
#define FTPLIB_PASSIVE 1
#define FTPLIB_PORT 2

/* connection option names */
#define FTPLIB_CONNMODE 1
#define FTPLIB_CALLBACK 2
#define FTPLIB_IDLETIME 3
#define FTPLIB_CALLBACKARG 4
#define FTPLIB_CALLBACKBYTES 5

#ifdef __cplusplus
extern "C" {
#endif

typedef struct NetBuf netbuf;
typedef int (*FtpCallback)(netbuf *nControl, int xfered, void *arg);

/* v1 compatibility stuff */
#if !defined(_FTPLIB_NO_COMPAT)
netbuf *DefaultNetbuf;

#define ftplib_lastresp FtpLastResponse(DefaultNetbuf)
#define ftpInit FtpInit
#define ftpOpen(x) FtpConnect(x, &DefaultNetbuf)
#define ftpLogin(x,y) FtpLogin(x, y, DefaultNetbuf)
#define ftpSite(x) FtpSite(x, DefaultNetbuf)
#define ftpMkdir(x) FtpMkdir(x, DefaultNetbuf)
#define ftpChdir(x) FtpChdir(x, DefaultNetbuf)
#define ftpRmdir(x) FtpRmdir(x, DefaultNetbuf)
#define ftpNlst(x, y) FtpNlst(x, y, DefaultNetbuf)
#define ftpDir(x, y) FtpDir(x, y, DefaultNetbuf)
#define ftpGet(x, y, z) FtpGet(x, y, z, DefaultNetbuf)
#define ftpPut(x, y, z) FtpPut(x, y, z, DefaultNetbuf)
#define ftpRename(x, y) FtpRename(x, y, DefaultNetbuf)
#define ftpDelete(x) FtpDelete(x, DefaultNetbuf)
#define ftpQuit() FtpQuit(DefaultNetbuf)
#endif /* (_FTPLIB_NO_COMPAT) */
/* end v1 compatibility stuff */

GLOBALREF int ftplib_debug;
GLOBALREF void FtpInit(void);
GLOBALREF char *FtpLastResponse(netbuf *nControl);
GLOBALREF int FtpConnect(const char *host, netbuf **nControl);
GLOBALREF int FtpOptions(int opt, long val, netbuf *nControl);
GLOBALREF int FtpLogin(const char *user, const char *pass, netbuf *nControl);
GLOBALREF int FtpAccess(const char *path, int typ, int mode, netbuf *nControl, netbuf **nData);
GLOBALREF int FtpRead(void *buf, int max, netbuf *nData);
GLOBALREF int FtpWrite(void *buf, int len, netbuf *nData);
GLOBALREF int FtpClose(netbuf *nData);
GLOBALREF int FtpSite(const char *cmd, netbuf *nControl);
GLOBALREF int FtpSysType(char *buf, int max, netbuf *nControl);
GLOBALREF int FtpMkdir(const char *path, netbuf *nControl);
GLOBALREF int FtpChdir(const char *path, netbuf *nControl);
GLOBALREF int FtpCDUp(netbuf *nControl);
GLOBALREF int FtpRmdir(const char *path, netbuf *nControl);
GLOBALREF int FtpPwd(char *path, int max, netbuf *nControl);
GLOBALREF int FtpNlst(const char *output, const char *path, netbuf *nControl);
GLOBALREF int FtpDir(const char *output, const char *path, netbuf *nControl);
GLOBALREF int FtpSize(const char *path, int *size, char mode, netbuf *nControl);
GLOBALREF int FtpModDate(const char *path, char *dt, int max, netbuf *nControl);
GLOBALREF int FtpGet(const char *output, const char *path, char mode, netbuf *nControl);
GLOBALREF int FtpPut(const char *input, const char *path, char mode, netbuf *nControl);
GLOBALREF int FtpRename(const char *src, const char *dst, netbuf *nControl);
GLOBALREF int FtpDelete(const char *fnm, netbuf *nControl);
GLOBALREF void FtpQuit(netbuf *nControl);

#ifdef __cplusplus
};
#endif

#endif /* __FTPLIB_H */

ftplib.c：

/***************************************************************************/
/*									   */
/* ftplib.c - callable ftp access routines				   */
/* Copyright (C) 1996-2001 Thomas Pfau, pfau@eclipse.net		   */
/*	1407 Thomas Ave, North Brunswick, NJ, 08902			   */
/*									   */
/* This library is free software; you can redistribute it and/or	   */
/* modify it under the terms of the GNU Library General Public		   */
/* License as published by the Free Software Foundation; either		   */
/* version 2 of the License, or (at your option) any later version.	   */
/* 									   */
/* This library is distributed in the hope that it will be useful,	   */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of	   */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU	   */
/* Library General Public License for more details.			   */
/* 									   */
/* You should have received a copy of the GNU Library General Public	   */
/* License along with this progam; if not, write to the			   */
/* Free Software Foundation, Inc., 59 Temple Place - Suite 330,		   */
/* Boston, MA 02111-1307, USA.						   */
/* 									   */
/***************************************************************************/

#if defined(__unix__) || defined(__VMS)
#include <unistd.h>
#endif
#if defined(_WIN32)
#include <windows.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#if defined(__unix__)
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#elif defined(VMS)
#include <types.h>
#include <socket.h>
#include <in.h>
#include <netdb.h>
#include <inet.h>
#elif defined(_WIN32)
#include <winsock.h>
#pragma comment(lib, "ws2_32.lib")
#endif

#define BUILDING_LIBRARY
#include "ftplib.h"

#if defined(_WIN32)
#define SETSOCKOPT_OPTVAL_TYPE (const char *)
#else
#define SETSOCKOPT_OPTVAL_TYPE (void *)
#endif

#define FTPLIB_BUFSIZ 8192
#define ACCEPT_TIMEOUT 30

#define FTPLIB_CONTROL 0
#define FTPLIB_READ 1
#define FTPLIB_WRITE 2

#if !defined FTPLIB_DEFMODE
#define FTPLIB_DEFMODE FTPLIB_PASSIVE
#endif

struct NetBuf {
	char *cput, *cget;
	int handle;
	int cavail, cleft;
	char *buf;
	int dir;
	netbuf *ctrl;
	netbuf *data;
	int cmode;
	struct timeval idletime;
	FtpCallback idlecb;
	void *idlearg;
	int xfered;
	int cbbytes;
	int xfered1;
	char response[256];
};

static char *version = "ftplib Release 3.1-1 9/16/00, copyright 1996-2000 Thomas Pfau";

GLOBALDEF int ftplib_debug = 0;

#if defined(__unix__) || defined(VMS)
#define net_read read
#define net_write write
#define net_close close
#elif defined(_WIN32)
#define net_read(x,y,z) recv(x,y,z,0)
#define net_write(x,y,z) send(x,y,z,0)
#define net_close closesocket
#endif

#if defined(NEED_MEMCCPY)
/*
 * VAX C does not supply a memccpy routine so I provide my own
 */
void *memccpy(void *dest, const void *src, int c, size_t n)
{
	int i=0;
	const unsigned char *ip=src;
	unsigned char *op=dest;

	while (i < n)
	{
		if ((*op++ = *ip++) == c)
		break;
		i++;
	}
	if (i == n)
	return NULL;
	return op;
}
#endif
#if defined(NEED_STRDUP)
/*
 * strdup - return a malloc'ed copy of a string
 */
char *strdup(const char *src)
{
	int l = strlen(src) + 1;
	char *dst = malloc(l);
	if (dst)
	strcpy(dst,src);
	return dst;
}
#endif

/*
 * socket_wait - wait for socket to receive or flush data
 *
 * return 1 if no user callback, otherwise, return value returned by
 * user callback
 */
static int socket_wait(netbuf *ctl) {
	fd_set fd, *rfd = NULL, *wfd = NULL;
	struct timeval tv;
	int rv = 0;
	if ((ctl->dir == FTPLIB_CONTROL) || (ctl->idlecb == NULL))
		return 1;
	if (ctl->dir == FTPLIB_WRITE)
		wfd = &fd;
	else
		rfd = &fd;
	FD_ZERO(&fd);
	do {
		FD_SET(ctl->handle, &fd);
		tv = ctl->idletime;
		rv = select(ctl->handle + 1, rfd, wfd, NULL, &tv);
		if (rv == -1) {
			rv = 0;
			strncpy(ctl->ctrl->response, strerror(errno), sizeof(ctl->ctrl->response));
			break;
		} else if (rv > 0) {
			rv = 1;
			break;
		}
	} while ((rv = ctl->idlecb(ctl, ctl->xfered, ctl->idlearg)));
	return rv;
}

/*
 * read a line of text
 *
 * return -1 on error or bytecount
 */
static int readline(char *buf, int max, netbuf *ctl) {
	int x, retval = 0;
	char *end, *bp = buf;
	int eof = 0;

	if ((ctl->dir != FTPLIB_CONTROL) && (ctl->dir != FTPLIB_READ))
		return -1;
	if (max == 0)
		return 0;
	do {
		if (ctl->cavail > 0) {
			x = (max >= ctl->cavail) ? ctl->cavail : max - 1;
			end = memccpy(bp, ctl->cget, '\n', x);
			if (end != NULL)
				x = end - bp;
			retval += x;
			bp += x;
			*bp = '\0';
			max -= x;
			ctl->cget += x;
			ctl->cavail -= x;
			if (end != NULL) {
				bp -= 2;
				if (strcmp(bp, "\r\n") == 0) {
					*bp++ = '\n';
					*bp++ = '\0';
					--retval;
				}
				break;
			}
		}
		if (max == 1) {
			*buf = '\0';
			break;
		}
		if (ctl->cput == ctl->cget) {
			ctl->cput = ctl->cget = ctl->buf;
			ctl->cavail = 0;
			ctl->cleft = FTPLIB_BUFSIZ;
		}
		if (eof) {
			if (retval == 0)
				retval = -1;
			break;
		}
		if (!socket_wait(ctl))
			return retval;
		if ((x = net_read(ctl->handle,ctl->cput,ctl->cleft)) == -1) {
			perror("read");
			retval = -1;
			break;
		}
		if (x == 0)
			eof = 1;
		ctl->cleft -= x;
		ctl->cavail += x;
		ctl->cput += x;
	} while (1);
	return retval;
}

/*
 * write lines of text
 *
 * return -1 on error or bytecount
 */
static int writeline(char *buf, int len, netbuf *nData) {
	int x, nb = 0, w;
	char *ubp = buf, *nbp;
	char lc = 0;

	if (nData->dir != FTPLIB_WRITE)
		return -1;
	nbp = nData->buf;
	for (x = 0; x < len; x++) {
		if ((*ubp == '\n') && (lc != '\r')) {
			if (nb == FTPLIB_BUFSIZ) {
				if (!socket_wait(nData))
					return x;
				w = net_write(nData->handle, nbp, FTPLIB_BUFSIZ);
				if (w != FTPLIB_BUFSIZ) {
					printf("net_write(1) returned %d, errno = %d\n", w, errno);
					return (-1);
				}
				nb = 0;
			}
			nbp[nb++] = '\r';
		}
		if (nb == FTPLIB_BUFSIZ) {
			if (!socket_wait(nData))
				return x;
			w = net_write(nData->handle, nbp, FTPLIB_BUFSIZ);
			if (w != FTPLIB_BUFSIZ) {
				printf("net_write(2) returned %d, errno = %d\n", w, errno);
				return (-1);
			}
			nb = 0;
		}
		nbp[nb++] = lc = *ubp++;
	}
	if (nb) {
		if (!socket_wait(nData))
			return x;
		w = net_write(nData->handle, nbp, nb);
		if (w != nb) {
			printf("net_write(3) returned %d, errno = %d\n", w, errno);
			return (-1);
		}
	}
	return len;
}

/*
 * read a response from the server
 *
 * return 0 if first char doesn't match
 * return 1 if first char matches
 */
static int readresp(char c, netbuf *nControl) {
	char match[5];
	if (readline(nControl->response, 256, nControl) == -1) {
		perror("Control socket read failed");
		return 0;
	}
	if (ftplib_debug > 1)
		fprintf(stderr, "%s", nControl->response);
	if (nControl->response[3] == '-') {
		strncpy(match, nControl->response, 3);
		match[3] = ' ';
		match[4] = '\0';
		do {
			if (readline(nControl->response, 256, nControl) == -1) {
				perror("Control socket read failed");
				return 0;
			}
			if (ftplib_debug > 1)
				fprintf(stderr, "%s", nControl->response);
		} while (strncmp(nControl->response, match, 4));
	}
	if (nControl->response[0] == c)
		return 1;
	return 0;
}

/*
 * FtpInit for stupid operating systems that require it (Windows NT)
 */
GLOBALDEF void FtpInit(void) {
#if defined(_WIN32)
	WORD wVersionRequested;
	WSADATA wsadata;
	int err;
	wVersionRequested = MAKEWORD(1, 1);
	if ((err = WSAStartup(wVersionRequested, &wsadata)) != 0)
		fprintf(stderr, "Network failed to start: %d\n", err);
#endif
}

/*
 * FtpLastResponse - return a pointer to the last response received
 */
GLOBALDEF char *FtpLastResponse(netbuf *nControl) {
	if ((nControl) && (nControl->dir == FTPLIB_CONTROL))
		return nControl->response;
	return NULL;
}

/*
 * FtpConnect - connect to remote server
 *
 * return 1 if connected, 0 if not
 */
GLOBALDEF int FtpConnect(const char *host, netbuf **nControl) {
	int sControl;
	struct sockaddr_in sin;
	struct hostent *phe;
	struct servent *pse;
	int on = 1;
	netbuf *ctrl;
	char *lhost;
	char *pnum;

	memset(&sin, 0, sizeof(sin));
	sin.sin_family = AF_INET;
	lhost = strdup(host);
	pnum = strchr(lhost, ':');
	if (pnum == NULL) {
#if defined(VMS)
		sin.sin_port = htons(21);
#else
		if ((pse = getservbyname("ftp", "tcp")) == NULL) {
			perror("getservbyname");
			return 0;
		}
		sin.sin_port = pse->s_port;
#endif
	} else {
		*pnum++ = '\0';
		if (isdigit(*pnum))
			sin.sin_port = htons((short) atoi(pnum));
		else {
			pse = getservbyname(pnum, "tcp");
			sin.sin_port = pse->s_port;
		}
	}
	if ((sin.sin_addr.s_addr = inet_addr(lhost)) == -1) {
		if ((phe = gethostbyname(lhost)) == NULL) {
			perror("gethostbyname");
			return 0;
		}
		memcpy((char *) &sin.sin_addr, phe->h_addr, phe->h_length);
	}
	free(lhost);
	sControl = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (sControl == -1) {
		perror("socket");
		return 0;
	}
	if (setsockopt(sControl, SOL_SOCKET, SO_REUSEADDR,
	SETSOCKOPT_OPTVAL_TYPE &on, sizeof(on)) == -1) {
		perror("setsockopt");
		net_close(sControl);
		return 0;
	}
	if (connect(sControl, (struct sockaddr *) &sin, sizeof(sin)) == -1) {
		perror("connect");
		net_close(sControl);
		return 0;
	}
	ctrl = (netbuf *)calloc(1, sizeof(netbuf));
	if (ctrl == NULL) {
		perror("calloc");
		net_close(sControl);
		return 0;
	}
	ctrl->buf = (char *)malloc(FTPLIB_BUFSIZ);
	if (ctrl->buf == NULL) {
		perror("calloc");
		net_close(sControl);
		free(ctrl);
		return 0;
	}
	ctrl->handle = sControl;
	ctrl->dir = FTPLIB_CONTROL;
	ctrl->ctrl = NULL;
	ctrl->cmode = FTPLIB_DEFMODE;
	ctrl->idlecb = NULL;
	ctrl->idletime.tv_sec = ctrl->idletime.tv_usec = 0;
	ctrl->idlearg = NULL;
	ctrl->xfered = 0;
	ctrl->xfered1 = 0;
	ctrl->cbbytes = 0;
	if (readresp('2', ctrl) == 0) {
		net_close(sControl);
		free(ctrl->buf);
		free(ctrl);
		return 0;
	}
	*nControl = ctrl;
	return 1;
}

/*
 * FtpOptions - change connection options
 *
 * returns 1 if successful, 0 on error
 */
GLOBALDEF int FtpOptions(int opt, long val, netbuf *nControl) {
	int v, rv = 0;
	switch (opt) {
	case FTPLIB_CONNMODE:
		v = (int) val;
		if ((v == FTPLIB_PASSIVE) || (v == FTPLIB_PORT)) {
			nControl->cmode = v;
			rv = 1;
		}
		break;
	case FTPLIB_CALLBACK:
		nControl->idlecb = (FtpCallback) val;
		rv = 1;
		break;
	case FTPLIB_IDLETIME:
		v = (int) val;
		rv = 1;
		nControl->idletime.tv_sec = v / 1000;
		nControl->idletime.tv_usec = (v % 1000) * 1000;
		break;
	case FTPLIB_CALLBACKARG:
		rv = 1;
		nControl->idlearg = (void *) val;
		break;
	case FTPLIB_CALLBACKBYTES:
		rv = 1;
		nControl->cbbytes = (int) val;
		break;
	}
	return rv;
}

/*
 * FtpSendCmd - send a command and wait for expected response
 *
 * return 1 if proper response received, 0 otherwise
 */
static int FtpSendCmd(const char *cmd, char expresp, netbuf *nControl) {
	char buf[256];
	if (nControl->dir != FTPLIB_CONTROL)
		return 0;
	if (ftplib_debug > 2)
		fprintf(stderr, "%s\n", cmd);
	if ((strlen(cmd) + 3) > sizeof(buf))
		return 0;
	sprintf(buf, "%s\r\n", cmd);
	if (net_write(nControl->handle,buf,strlen(buf)) <= 0) {
		perror("write");
		return 0;
	}
	return readresp(expresp, nControl);
}

/*
 * FtpLogin - log in to remote server
 *
 * return 1 if logged in, 0 otherwise
 */
GLOBALDEF int FtpLogin(const char *user, const char *pass, netbuf *nControl) {
	char tempbuf[64];

	if (((strlen(user) + 7) > sizeof(tempbuf)) || ((strlen(pass) + 7) > sizeof(tempbuf)))
		return 0;
	sprintf(tempbuf, "USER %s", user);
	if (!FtpSendCmd(tempbuf, '3', nControl)) {
		if (nControl->response[0] == '2')
			return 1;
		return 0;
	}
	sprintf(tempbuf, "PASS %s", pass);
	return FtpSendCmd(tempbuf, '2', nControl);
}

/*
 * FtpOpenPort - set up data connection
 *
 * return 1 if successful, 0 otherwise
 */
static int FtpOpenPort(netbuf *nControl, netbuf **nData, int mode, int dir) {
	int sData;
	union {
		struct sockaddr sa;
		struct sockaddr_in in;
	} sin;
	struct linger lng = { 0, 0 };
	unsigned int l;
	int on = 1;
	netbuf *ctrl;
	char *cp;
	unsigned int v[6];
	char buf[256];

	if (nControl->dir != FTPLIB_CONTROL)
		return -1;
	if ((dir != FTPLIB_READ) && (dir != FTPLIB_WRITE)) {
		sprintf(nControl->response, "Invalid direction %d\n", dir);
		return -1;
	}
	if ((mode != FTPLIB_ASCII) && (mode != FTPLIB_IMAGE)) {
		sprintf(nControl->response, "Invalid mode %c\n", mode);
		return -1;
	}
	l = sizeof(sin);
	if (nControl->cmode == FTPLIB_PASSIVE) {
		memset(&sin, 0, l);
		sin.in.sin_family = AF_INET;
		if (!FtpSendCmd("PASV", '2', nControl))
			return -1;
		cp = strchr(nControl->response, '(');
		if (cp == NULL)
			return -1;
		cp++;
		sscanf(cp, "%u,%u,%u,%u,%u,%u", &v[2], &v[3], &v[4], &v[5], &v[0], &v[1]);
		sin.sa.sa_data[2] = v[2];
		sin.sa.sa_data[3] = v[3];
		sin.sa.sa_data[4] = v[4];
		sin.sa.sa_data[5] = v[5];
		sin.sa.sa_data[0] = v[0];
		sin.sa.sa_data[1] = v[1];
	} else {
		if (getsockname(nControl->handle, &sin.sa, &l) < 0) {
			perror("getsockname");
			return 0;
		}
	}
	sData = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (sData == -1) {
		perror("socket");
		return -1;
	}
	if (setsockopt(sData, SOL_SOCKET, SO_REUSEADDR,
	SETSOCKOPT_OPTVAL_TYPE &on, sizeof(on)) == -1) {
		perror("setsockopt");
		net_close(sData);
		return -1;
	}
	if (setsockopt(sData, SOL_SOCKET, SO_LINGER,
	SETSOCKOPT_OPTVAL_TYPE &lng, sizeof(lng)) == -1) {
		perror("setsockopt");
		net_close(sData);
		return -1;
	}
	if (nControl->cmode == FTPLIB_PASSIVE) {
		if (connect(sData, &sin.sa, sizeof(sin.sa)) == -1) {
			perror("connect");
			net_close(sData);
			return -1;
		}
	} else {
		sin.in.sin_port = 0;
		if (bind(sData, &sin.sa, sizeof(sin)) == -1) {
			perror("bind");
			net_close(sData);
			return 0;
		}
		if (listen(sData, 1) < 0) {
			perror("listen");
			net_close(sData);
			return 0;
		}
		if (getsockname(sData, &sin.sa, &l) < 0)
			return 0;
		sprintf(buf, "PORT %d,%d,%d,%d,%d,%d", (unsigned char) sin.sa.sa_data[2], (unsigned char) sin.sa.sa_data[3], (unsigned char) sin.sa.sa_data[4], (unsigned char) sin.sa.sa_data[5], (unsigned char) sin.sa.sa_data[0], (unsigned char) sin.sa.sa_data[1]);
		if (!FtpSendCmd(buf, '2', nControl)) {
			net_close(sData);
			return 0;
		}
	}
	ctrl = (netbuf *)calloc(1, sizeof(netbuf));
	if (ctrl == NULL) {
		perror("calloc");
		net_close(sData);
		return -1;
	}
	if ((mode == 'A') && ((ctrl->buf = malloc(FTPLIB_BUFSIZ)) == NULL)) {
		perror("calloc");
		net_close(sData);
		free(ctrl);
		return -1;
	}
	ctrl->handle = sData;
	ctrl->dir = dir;
	ctrl->idletime = nControl->idletime;
	ctrl->idlearg = nControl->idlearg;
	ctrl->xfered = 0;
	ctrl->xfered1 = 0;
	ctrl->cbbytes = nControl->cbbytes;
	if (ctrl->idletime.tv_sec || ctrl->idletime.tv_usec || ctrl->cbbytes)
		ctrl->idlecb = nControl->idlecb;
	else
		ctrl->idlecb = NULL;
	*nData = ctrl;
	return 1;
}

/*
 * FtpAcceptConnection - accept connection from server
 *
 * return 1 if successful, 0 otherwise
 */
static int FtpAcceptConnection(netbuf *nData, netbuf *nControl) {
	int sData;
	struct sockaddr addr;
	unsigned int l;
	int i;
	struct timeval tv;
	fd_set mask;
	int rv;

	FD_ZERO(&mask);
	FD_SET(nControl->handle, &mask);
	FD_SET(nData->handle, &mask);
	tv.tv_usec = 0;
	tv.tv_sec = ACCEPT_TIMEOUT;
	i = nControl->handle;
	if (i < nData->handle)
		i = nData->handle;
	i = select(i + 1, &mask, NULL, NULL, &tv);
	if (i == -1) {
		strncpy(nControl->response, strerror(errno), sizeof(nControl->response));
		net_close(nData->handle);
		nData->handle = 0;
		rv = 0;
	} else if (i == 0) {
		strcpy(nControl->response, "timed out waiting for connection");
		net_close(nData->handle);
		nData->handle = 0;
		rv = 0;
	} else {
		if (FD_ISSET(nData->handle, &mask)) {
			l = sizeof(addr);
			sData = accept(nData->handle, &addr, &l);
			i = errno;
			net_close(nData->handle);
			if (sData > 0) {
				rv = 1;
				nData->handle = sData;
			} else {
				strncpy(nControl->response, strerror(i), sizeof(nControl->response));
				nData->handle = 0;
				rv = 0;
			}
		} else if (FD_ISSET(nControl->handle, &mask)) {
			net_close(nData->handle);
			nData->handle = 0;
			readresp('2', nControl);
			rv = 0;
		}
	}
	return rv;
}

/*
 * FtpAccess - return a handle for a data stream
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpAccess(const char *path, int typ, int mode, netbuf *nControl, netbuf **nData) {
	char buf[256];
	int dir;
	if ((path == NULL) && ((typ == FTPLIB_FILE_WRITE) || (typ == FTPLIB_FILE_READ))) {
		sprintf(nControl->response, "Missing path argument for file transfer\n");
		return 0;
	}
	sprintf(buf, "TYPE %c", mode);
	if (!FtpSendCmd(buf, '2', nControl))
		return 0;
	switch (typ) {
	case FTPLIB_DIR:
		strcpy(buf, "NLST");
		dir = FTPLIB_READ;
		break;
	case FTPLIB_DIR_VERBOSE:
		strcpy(buf, "LIST");
		dir = FTPLIB_READ;
		break;
	case FTPLIB_FILE_READ:
		strcpy(buf, "RETR");
		dir = FTPLIB_READ;
		break;
	case FTPLIB_FILE_WRITE:
		strcpy(buf, "STOR");
		dir = FTPLIB_WRITE;
		break;
	default:
		sprintf(nControl->response, "Invalid open type %d\n", typ);
		return 0;
	}
	if (path != NULL) {
		int i = strlen(buf);
		buf[i++] = ' ';
		if ((strlen(path) + i) >= sizeof(buf))
			return 0;
		strcpy(&buf[i], path);
	}
	if (FtpOpenPort(nControl, nData, mode, dir) == -1)
		return 0;
	if (!FtpSendCmd(buf, '1', nControl)) {
		FtpClose(*nData);
		*nData = NULL;
		return 0;
	}
	(*nData)->ctrl = nControl;
	nControl->data = *nData;
	if (nControl->cmode == FTPLIB_PORT) {
		if (!FtpAcceptConnection(*nData, nControl)) {
			FtpClose(*nData);
			*nData = NULL;
			nControl->data = NULL;
			return 0;
		}
	}
	return 1;
}

/*
 * FtpRead - read from a data connection
 */
GLOBALDEF int FtpRead(void *buf, int max, netbuf *nData) {
	int i;
	if (nData->dir != FTPLIB_READ)
		return 0;
	if (nData->buf)
		i = readline(buf, max, nData);
	else {
		i = socket_wait(nData);
		if (i != 1)
			return 0;
		i = net_read(nData->handle, buf, max);
	}
	if (i == -1)
		return 0;
	nData->xfered += i;
	if (nData->idlecb && nData->cbbytes) {
		nData->xfered1 += i;
		if (nData->xfered1 > nData->cbbytes) {
			if (nData->idlecb(nData, nData->xfered, nData->idlearg) == 0)
				return 0;
			nData->xfered1 = 0;
		}
	}
	return i;
}

/*
 * FtpWrite - write to a data connection
 */
GLOBALDEF int FtpWrite(void *buf, int len, netbuf *nData) {
	int i;
	if (nData->dir != FTPLIB_WRITE)
		return 0;
	if (nData->buf)
		i = writeline(buf, len, nData);
	else {
		socket_wait(nData);
		i = net_write(nData->handle, buf, len);
	}
	if (i == -1)
		return 0;
	nData->xfered += i;
	if (nData->idlecb && nData->cbbytes) {
		nData->xfered1 += i;
		if (nData->xfered1 > nData->cbbytes) {
			nData->idlecb(nData, nData->xfered, nData->idlearg);
			nData->xfered1 = 0;
		}
	}
	return i;
}

/*
 * FtpClose - close a data connection
 */
GLOBALDEF int FtpClose(netbuf *nData) {
	netbuf *ctrl;
	switch (nData->dir) {
	case FTPLIB_WRITE:
		/* potential problem - if buffer flush fails, how to notify user? */
		if (nData->buf != NULL)
			writeline(NULL, 0, nData);
	case FTPLIB_READ:
		if (nData->buf)
			free(nData->buf);
		shutdown(nData->handle, 2);
		net_close(nData->handle);
		ctrl = nData->ctrl;
		free(nData);
		if (ctrl) {
			ctrl->data = NULL;
			return (readresp('2', ctrl));
		}
		return 1;
	case FTPLIB_CONTROL:
		if (nData->data) {
			nData->ctrl = NULL;
			FtpClose(nData);
		}
		net_close(nData->handle);
		free(nData);
		return 0;
	}
	return 1;
}

/*
 * FtpSite - send a SITE command
 *
 * return 1 if command successful, 0 otherwise
 */
GLOBALDEF int FtpSite(const char *cmd, netbuf *nControl) {
	char buf[256];

	if ((strlen(cmd) + 7) > sizeof(buf))
		return 0;
	sprintf(buf, "SITE %s", cmd);
	if (!FtpSendCmd(buf, '2', nControl))
		return 0;
	return 1;
}

/*
 * FtpSysType - send a SYST command
 *
 * Fills in the user buffer with the remote system type.  If more
 * information from the response is required, the user can parse
 * it out of the response buffer returned by FtpLastResponse().
 *
 * return 1 if command successful, 0 otherwise
 */
GLOBALDEF int FtpSysType(char *buf, int max, netbuf *nControl) {
	int l = max;
	char *b = buf;
	char *s;
	if (!FtpSendCmd("SYST", '2', nControl))
		return 0;
	s = &nControl->response[4];
	while ((--l) && (*s != ' '))
		*b++ = *s++;
	*b++ = '\0';
	return 1;
}

/*
 * FtpMkdir - create a directory at server
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpMkdir(const char *path, netbuf *nControl) {
	char buf[256];

	if ((strlen(path) + 6) > sizeof(buf))
		return 0;
	sprintf(buf, "MKD %s", path);
	if (!FtpSendCmd(buf, '2', nControl))
		return 0;
	return 1;
}

/*
 * FtpChdir - change path at remote
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpChdir(const char *path, netbuf *nControl) {
	char buf[256];

	if ((strlen(path) + 6) > sizeof(buf))
		return 0;
	sprintf(buf, "CWD %s", path);
	if (!FtpSendCmd(buf, '2', nControl))
		return 0;
	return 1;
}

/*
 * FtpCDUp - move to parent directory at remote
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpCDUp(netbuf *nControl) {
	if (!FtpSendCmd("CDUP", '2', nControl))
		return 0;
	return 1;
}

/*
 * FtpRmdir - remove directory at remote
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpRmdir(const char *path, netbuf *nControl) {
	char buf[256];

	if ((strlen(path) + 6) > sizeof(buf))
		return 0;
	sprintf(buf, "RMD %s", path);
	if (!FtpSendCmd(buf, '2', nControl))
		return 0;
	return 1;
}

/*
 * FtpPwd - get working directory at remote
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpPwd(char *path, int max, netbuf *nControl) {
	int l = max;
	char *b = path;
	char *s;
	if (!FtpSendCmd("PWD", '2', nControl))
		return 0;
	s = strchr(nControl->response, '"');
	if (s == NULL)
		return 0;
	s++;
	while ((--l) && (*s) && (*s != '"'))
		*b++ = *s++;
	*b++ = '\0';
	return 1;
}

/*
 * FtpXfer - issue a command and transfer data
 *
 * return 1 if successful, 0 otherwise
 */
static int FtpXfer(const char *localfile, const char *path, netbuf *nControl, int typ, int mode) {
	int l, c;
	char *dbuf;
	FILE *local = NULL;
	netbuf *nData;
	int rv = 1;

	if (localfile != NULL) {
		char ac[4] = "w";
		if (typ == FTPLIB_FILE_WRITE)
			ac[0] = 'r';
		if (mode == FTPLIB_IMAGE)
			ac[1] = 'b';
		local = fopen(localfile, ac);
		if (local == NULL) {
			strncpy(nControl->response, strerror(errno), sizeof(nControl->response));
			return 0;
		}
	}
	if (local == NULL)
		local = (typ == FTPLIB_FILE_WRITE) ? stdin : stdout;
	if (!FtpAccess(path, typ, mode, nControl, &nData))
		return 0;
	dbuf = malloc(FTPLIB_BUFSIZ);
	if (typ == FTPLIB_FILE_WRITE) {
		while ((l = fread(dbuf, 1, FTPLIB_BUFSIZ, local)) > 0)
			if ((c = FtpWrite(dbuf, l, nData)) < l) {
				printf("short write: passed %d, wrote %d\n", l, c);
				rv = 0;
				break;
			}
	} else {
		while ((l = FtpRead(dbuf, FTPLIB_BUFSIZ, nData)) > 0)
			if (fwrite(dbuf, 1, l, local) <= 0) {
				perror("localfile write");
				rv = 0;
				break;
			}
	}
	free(dbuf);
	fflush(local);
	if (localfile != NULL)
		fclose(local);
	FtpClose(nData);
	return rv;
}

/*
 * FtpNlst - issue an NLST command and write response to output
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpNlst(const char *outputfile, const char *path, netbuf *nControl) {
	return FtpXfer(outputfile, path, nControl, FTPLIB_DIR, FTPLIB_ASCII);
}

/*
 * FtpDir - issue a LIST command and write response to output
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpDir(const char *outputfile, const char *path, netbuf *nControl) {
	return FtpXfer(outputfile, path, nControl, FTPLIB_DIR_VERBOSE, FTPLIB_ASCII);
}

/*
 * FtpSize - determine the size of a remote file
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpSize(const char *path, int *size, char mode, netbuf *nControl) {
	char cmd[256];
	int resp, sz, rv = 1;

	if ((strlen(path) + 7) > sizeof(cmd))
		return 0;
	sprintf(cmd, "TYPE %c", mode);
	if (!FtpSendCmd(cmd, '2', nControl))
		return 0;
	sprintf(cmd, "SIZE %s", path);
	if (!FtpSendCmd(cmd, '2', nControl))
		rv = 0;
	else {
		if (sscanf(nControl->response, "%d %d", &resp, &sz) == 2)
			*size = sz;
		else
			rv = 0;
	}
	return rv;
}

/*
 * FtpModDate - determine the modification date of a remote file
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpModDate(const char *path, char *dt, int max, netbuf *nControl) {
	char buf[256];
	int rv = 1;

	if ((strlen(path) + 7) > sizeof(buf))
		return 0;
	sprintf(buf, "MDTM %s", path);
	if (!FtpSendCmd(buf, '2', nControl))
		rv = 0;
	else
		strncpy(dt, &nControl->response[4], max);
	return rv;
}

/*
 * FtpGet - issue a GET command and write received data to output
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpGet(const char *outputfile, const char *path, char mode, netbuf *nControl) {
	return FtpXfer(outputfile, path, nControl, FTPLIB_FILE_READ, mode);
}

/*
 * FtpPut - issue a PUT command and send data from input
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpPut(const char *inputfile, const char *path, char mode, netbuf *nControl) {
	return FtpXfer(inputfile, path, nControl, FTPLIB_FILE_WRITE, mode);
}

/*
 * FtpRename - rename a file at remote
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpRename(const char *src, const char *dst, netbuf *nControl) {
	char cmd[256];

	if (((strlen(src) + 7) > sizeof(cmd)) || ((strlen(dst) + 7) > sizeof(cmd)))
		return 0;
	sprintf(cmd, "RNFR %s", src);
	if (!FtpSendCmd(cmd, '3', nControl))
		return 0;
	sprintf(cmd, "RNTO %s", dst);
	if (!FtpSendCmd(cmd, '2', nControl))
		return 0;
	return 1;
}

/*
 * FtpDelete - delete a file at remote
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF int FtpDelete(const char *fnm, netbuf *nControl) {
	char cmd[256];

	if ((strlen(fnm) + 7) > sizeof(cmd))
		return 0;
	sprintf(cmd, "DELE %s", fnm);
	if (!FtpSendCmd(cmd, '2', nControl))
		return 0;
	return 1;
}

/*
 * FtpQuit - disconnect from remote
 *
 * return 1 if successful, 0 otherwise
 */
GLOBALDEF void FtpQuit(netbuf *nControl) {
	if (nControl->dir != FTPLIB_CONTROL)
		return;
	FtpSendCmd("QUIT", '2', nControl);
	net_close(nControl->handle);
	free(nControl->buf);
	free(nControl);
}

getopt.h：

/* Declarations for getopt.
 Copyright (C) 1989, 90, 91, 92, 93, 94 Free Software Foundation, Inc.

 This file is part of the GNU C Library.  Its master source is NOT part of
 the C library, however.  The master source lives in /gd/gnu/lib.

 The GNU C Library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Library General Public License as
 published by the Free Software Foundation; either version 2 of the
 License, or (at your option) any later version.

 The GNU C Library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Library General Public License for more details.

 You should have received a copy of the GNU Library General Public
 License along with the GNU C Library; see the file COPYING.LIB.  If
 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
 Cambridge, MA 02139, USA.  */

#ifndef _GETOPT_H
#define _GETOPT_H 1

#ifdef	__cplusplus
extern "C" {
#endif

/* For communication from `getopt' to the caller.
 When `getopt' finds an option that takes an argument,
 the argument value is returned here.
 Also, when `ordering' is RETURN_IN_ORDER,
 each non-option ARGV-element is returned here.  */

extern char *optarg;

/* Index in ARGV of the next element to be scanned.
 This is used for communication to and from the caller
 and for communication between successive calls to `getopt'.

 On entry to `getopt', zero means this is the first call; initialize.

 When `getopt' returns EOF, this is the index of the first of the
 non-option elements that the caller should itself scan.

 Otherwise, `optind' communicates from one call to the next
 how much of ARGV has been scanned so far.  */

extern int optind;

/* Callers store zero here to inhibit the error message `getopt' prints
 for unrecognized options.  */

extern int opterr;

/* Set to an option character which was unrecognized.  */

extern int optopt;

/* Describe the long-named options requested by the application.
 The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
 of `struct option' terminated by an element containing a name which is
 zero.

 The field `has_arg' is:
 no_argument		(or 0) if the option does not take an argument,
 required_argument	(or 1) if the option requires an argument,
 optional_argument 	(or 2) if the option takes an optional argument.

 If the field `flag' is not NULL, it points to a variable that is set
 to the value given in the field `val' when the option is found, but
 left unchanged if the option is not found.

 To have a long-named option do something other than set an `int' to
 a compiled-in constant, such as set a value from `optarg', set the
 option's `flag' field to zero and its `val' field to a nonzero
 value (the equivalent single-letter option character, if there is
 one).  For long options that have a zero `flag' field, `getopt'
 returns the contents of the `val' field.  */

struct option {
#if defined (__STDC__) && __STDC__
	const char *name;
#else
	char *name;
#endif
	/* has_arg can't be an enum because some compilers complain about
	 type mismatches in all the code that assumes it is an int.  */
	int has_arg;
	int *flag;
	int val;
};

/* Names for the values of the `has_arg' field of `struct option'.  */

#define	no_argument		0
#define required_argument	1
#define optional_argument	2

#if defined (__STDC__) && __STDC__
#ifdef __GNU_LIBRARY__
/* Many other libraries have conflicting prototypes for getopt, with
 differences in the consts, in stdlib.h.  To avoid compilation
 errors, only prototype getopt for the GNU C library.  */
extern int getopt (int argc, char *const *argv, const char *shortopts);
#else /* not __GNU_LIBRARY__ */
extern int getopt();
#endif /* __GNU_LIBRARY__ */
extern int getopt_long(int argc, char * const *argv, const char *shortopts, const struct option *longopts, int *longind);
extern int getopt_long_only(int argc, char * const *argv, const char *shortopts, const struct option *longopts, int *longind);

/* Internal only.  Users should not call this directly.  */
extern int _getopt_internal(int argc, char * const *argv, const char *shortopts, const struct option *longopts, int *longind, int long_only);
#else /* not __STDC__ */
extern int getopt ();
extern int getopt_long ();
extern int getopt_long_only ();

extern int _getopt_internal ();
#endif /* __STDC__ */

#ifdef	__cplusplus
}
#endif

#endif /* _GETOPT_H */

getopt.c：

/* Getopt for GNU.
 NOTE: getopt is now part of the C library, so if you don't know what
 "Keep this file name-space clean" means, talk to roland@gnu.ai.mit.edu
 before changing it!

 Copyright (C) 1987, 88, 89, 90, 91, 92, 93, 94
 Free Software Foundation, Inc.

 This file is part of the GNU C Library.  Its master source is NOT part of
 the C library, however.  The master source lives in /gd/gnu/lib.

 The GNU C Library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Library General Public License as
 published by the Free Software Foundation; either version 2 of the
 License, or (at your option) any later version.

 The GNU C Library is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 Library General Public License for more details.

 You should have received a copy of the GNU Library General Public
 License along with the GNU C Library; see the file COPYING.LIB.  If
 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
 Cambridge, MA 02139, USA.  */

/* This tells Alpha OSF/1 not to define a getopt prototype in <stdio.h>.
 Ditto for AIX 3.2 and <stdlib.h>.  */
#ifndef _NO_PROTO
#define _NO_PROTO
#endif

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#if !defined (__STDC__) || !__STDC__
/* This is a separate conditional since some stdc systems
 reject `defined (const)'.  */
#ifndef const
#define const
#endif
#endif

#include <stdio.h>

#ifdef WIN32
#include <string.h>
#endif

/* Comment out all this code if we are using the GNU C Library, and are not
 actually compiling the library itself.  This code is part of the GNU C
 Library, but also included in many other GNU distributions.  Compiling
 and linking in this code is a waste when using the GNU C library
 (especially if it is a shared library).  Rather than having every GNU
 program understand `configure --with-gnu-libc' and omit the object files,
 it is simpler to just do this in the source for each such file.  */

#if defined (_LIBC) || !defined (__GNU_LIBRARY__)

/* This needs to come after some library #include
 to get __GNU_LIBRARY__ defined.  */
#ifdef	__GNU_LIBRARY__
/* Don't include stdlib.h for non-GNU C libraries because some of them
 contain conflicting prototypes for getopt.  */
#include <stdlib.h>
#endif	/* GNU C library.  */

/* This version of `getopt' appears to the caller like standard Unix `getopt'
 but it behaves differently for the user, since it allows the user
 to intersperse the options with the other arguments.

 As `getopt' works, it permutes the elements of ARGV so that,
 when it is done, all the options precede everything else.  Thus
 all application programs are extended to handle flexible argument order.

 Setting the environment variable POSIXLY_CORRECT disables permutation.
 Then the behavior is completely standard.

 GNU application programs can use a third alternative mode in which
 they can distinguish the relative order of options and other arguments.  */

#include "getopt.h"

/* For communication from `getopt' to the caller.
 When `getopt' finds an option that takes an argument,
 the argument value is returned here.
 Also, when `ordering' is RETURN_IN_ORDER,
 each non-option ARGV-element is returned here.  */

char *optarg = NULL;

/* Index in ARGV of the next element to be scanned.
 This is used for communication to and from the caller
 and for communication between successive calls to `getopt'.

 On entry to `getopt', zero means this is the first call; initialize.

 When `getopt' returns EOF, this is the index of the first of the
 non-option elements that the caller should itself scan.

 Otherwise, `optind' communicates from one call to the next
 how much of ARGV has been scanned so far.  */

/* XXX 1003.2 says this must be 1 before any call.  */
int optind = 0;

/* The next char to be scanned in the option-element
 in which the last option character we returned was found.
 This allows us to pick up the scan where we left off.

 If this is zero, or a null string, it means resume the scan
 by advancing to the next ARGV-element.  */

static char *nextchar;

/* Callers store zero here to inhibit the error message
 for unrecognized options.  */

int opterr = 1;

/* Set to an option character which was unrecognized.
 This must be initialized on some systems to avoid linking in the
 system's own getopt implementation.  */

int optopt = '?';

/* Describe how to deal with options that follow non-option ARGV-elements.

 If the caller did not specify anything,
 the default is REQUIRE_ORDER if the environment variable
 POSIXLY_CORRECT is defined, PERMUTE otherwise.

 REQUIRE_ORDER means don't recognize them as options;
 stop option processing when the first non-option is seen.
 This is what Unix does.
 This mode of operation is selected by either setting the environment
 variable POSIXLY_CORRECT, or using `+' as the first character
 of the list of option characters.

 PERMUTE is the default.  We permute the contents of ARGV as we scan,
 so that eventually all the non-options are at the end.  This allows options
 to be given in any order, even with programs that were not written to
 expect this.

 RETURN_IN_ORDER is an option available to programs that were written
 to expect options and other ARGV-elements in any order and that care about
 the ordering of the two.  We describe each non-option ARGV-element
 as if it were the argument of an option with character code 1.
 Using `-' as the first character of the list of option characters
 selects this mode of operation.

 The special argument `--' forces an end of option-scanning regardless
 of the value of `ordering'.  In the case of RETURN_IN_ORDER, only
 `--' can cause `getopt' to return EOF with `optind' != ARGC.  */

static enum {
	REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER
} ordering;

/* Value of POSIXLY_CORRECT environment variable.  */
static char *posixly_correct;

#ifdef	__GNU_LIBRARY__
/* We want to avoid inclusion of string.h with non-GNU libraries
 because there are many ways it can cause trouble.
 On some systems, it contains special magic macros that don't work
 in GCC.  */
#include <string.h>
#define	my_index	strchr
#else

/* Avoid depending on library functions or files
 whose names are inconsistent.  */

char *getenv();

static char * my_index(str, chr)
	const char *str;int chr; {
	while (*str) {
		if (*str == chr)
			return (char *) str;
		str++;
	}
	return 0;
}

/* If using GCC, we can safely declare strlen this way.
 If not using GCC, it is ok not to declare it.  */
#ifdef __GNUC__
/* Note that Motorola Delta 68k R3V7 comes with GCC but not stddef.h.
 That was relevant to code that was here before.  */
#if !defined (__STDC__) || !__STDC__
/* gcc with -traditional declares the built-in strlen to return int,
 and has done so at least since version 2.4.5. -- rms.  */
extern int strlen (const char *);
#endif /* not __STDC__ */
#endif /* __GNUC__ */

#endif /* not __GNU_LIBRARY__ */

/* Handle permutation of arguments.  */

/* Describe the part of ARGV that contains non-options that have
 been skipped.  `first_nonopt' is the index in ARGV of the first of them;
 `last_nonopt' is the index after the last of them.  */

static int first_nonopt;
static int last_nonopt;

/* Exchange two adjacent subsequences of ARGV.
 One subsequence is elements [first_nonopt,last_nonopt)
 which contains all the non-options that have been skipped so far.
 The other is elements [last_nonopt,optind), which contains all
 the options processed since those non-options were skipped.

 `first_nonopt' and `last_nonopt' are relocated so that they describe
 the new indices of the non-options in ARGV after they are moved.  */

static void exchange(argv)
	char **argv; {
	int bottom = first_nonopt;
	int middle = last_nonopt;
	int top = optind;
	char *tem;

	/* Exchange the shorter segment with the far end of the longer segment.
	 That puts the shorter segment into the right place.
	 It leaves the longer segment in the right place overall,
	 but it consists of two parts that need to be swapped next.  */

	while (top > middle && middle > bottom) {
		if (top - middle > middle - bottom) {
			/* Bottom segment is the short one.  */
			int len = middle - bottom;
			register int i;

			/* Swap it with the top part of the top segment.  */
			for (i = 0; i < len; i++) {
				tem = argv[bottom + i];
				argv[bottom + i] = argv[top - (middle - bottom) + i];
				argv[top - (middle - bottom) + i] = tem;
			}
			/* Exclude the moved bottom segment from further swapping.  */
			top -= len;
		} else {
			/* Top segment is the short one.  */
			int len = top - middle;
			register int i;

			/* Swap it with the bottom part of the bottom segment.  */
			for (i = 0; i < len; i++) {
				tem = argv[bottom + i];
				argv[bottom + i] = argv[middle + i];
				argv[middle + i] = tem;
			}
			/* Exclude the moved top segment from further swapping.  */
			bottom += len;
		}
	}

	/* Update records for the slots the non-options now occupy.  */

	first_nonopt += (optind - last_nonopt);
	last_nonopt = optind;
}

/* Initialize the internal data when the first call is made.  */

static const char * _getopt_initialize(optstring)
	const char *optstring; {
	/* Start processing options with ARGV-element 1 (since ARGV-element 0
	 is the program name); the sequence of previously skipped
	 non-option ARGV-elements is empty.  */

	first_nonopt = last_nonopt = optind = 1;

	nextchar = NULL;

	posixly_correct = getenv("POSIXLY_CORRECT");

	/* Determine how to handle the ordering of options and nonoptions.  */

	if (optstring[0] == '-') {
		ordering = RETURN_IN_ORDER;
		++optstring;
	} else if (optstring[0] == '+') {
		ordering = REQUIRE_ORDER;
		++optstring;
	} else if (posixly_correct != NULL)
		ordering = REQUIRE_ORDER;
	else
		ordering = PERMUTE;

	return optstring;
}

/* Scan elements of ARGV (whose length is ARGC) for option characters
 given in OPTSTRING.

 If an element of ARGV starts with '-', and is not exactly "-" or "--",
 then it is an option element.  The characters of this element
 (aside from the initial '-') are option characters.  If `getopt'
 is called repeatedly, it returns successively each of the option characters
 from each of the option elements.

 If `getopt' finds another option character, it returns that character,
 updating `optind' and `nextchar' so that the next call to `getopt' can
 resume the scan with the following option character or ARGV-element.

 If there are no more option characters, `getopt' returns `EOF'.
 Then `optind' is the index in ARGV of the first ARGV-element
 that is not an option.  (The ARGV-elements have been permuted
 so that those that are not options now come last.)

 OPTSTRING is a string containing the legitimate option characters.
 If an option character is seen that is not listed in OPTSTRING,
 return '?' after printing an error message.  If you set `opterr' to
 zero, the error message is suppressed but we still return '?'.

 If a char in OPTSTRING is followed by a colon, that means it wants an arg,
 so the following text in the same ARGV-element, or the text of the following
 ARGV-element, is returned in `optarg'.  Two colons mean an option that
 wants an optional arg; if there is text in the current ARGV-element,
 it is returned in `optarg', otherwise `optarg' is set to zero.

 If OPTSTRING starts with `-' or `+', it requests different methods of
 handling the non-option ARGV-elements.
 See the comments about RETURN_IN_ORDER and REQUIRE_ORDER, above.

 Long-named options begin with `--' instead of `-'.
 Their names may be abbreviated as long as the abbreviation is unique
 or is an exact match for some defined option.  If they have an
 argument, it follows the option name in the same ARGV-element, separated
 from the option name by a `=', or else the in next ARGV-element.
 When `getopt' finds a long-named option, it returns 0 if that option's
 `flag' field is nonzero, the value of the option's `val' field
 if the `flag' field is zero.

 The elements of ARGV aren't really const, because we permute them.
 But we pretend they're const in the prototype to be compatible
 with other systems.

 LONGOPTS is a vector of `struct option' terminated by an
 element containing a name which is zero.

 LONGIND returns the index in LONGOPT of the long-named option found.
 It is only valid when a long-named option has been found by the most
 recent call.

 If LONG_ONLY is nonzero, '-' as well as '--' can introduce
 long-named options.  */

int _getopt_internal(argc, argv, optstring, longopts, longind, long_only)
	int argc;char * const *argv;const char *optstring;const struct option *longopts;int *longind;int long_only; {
	optarg = NULL;

	if (optind == 0)
		optstring = _getopt_initialize(optstring);

	if (nextchar == NULL || *nextchar == '\0') {
		/* Advance to the next ARGV-element.  */

		if (ordering == PERMUTE) {
			/* If we have just processed some options following some non-options,
			 exchange them so that the options come first.  */

			if (first_nonopt != last_nonopt && last_nonopt != optind)
				exchange((char **) argv);
			else if (last_nonopt != optind)
				first_nonopt = optind;

			/* Skip any additional non-options
			 and extend the range of non-options previously skipped.  */

			while (optind < argc && (argv[optind][0] != '-' || argv[optind][1] == '\0'))
				optind++;
			last_nonopt = optind;
		}

		/* The special ARGV-element `--' means premature end of options.
		 Skip it like a null option,
		 then exchange with previous non-options as if it were an option,
		 then skip everything else like a non-option.  */

		if (optind != argc && !strcmp(argv[optind], "--")) {
			optind++;

			if (first_nonopt != last_nonopt && last_nonopt != optind)
				exchange((char **) argv);
			else if (first_nonopt == last_nonopt)
				first_nonopt = optind;
			last_nonopt = argc;

			optind = argc;
		}

		/* If we have done all the ARGV-elements, stop the scan
		 and back over any non-options that we skipped and permuted.  */

		if (optind == argc) {
			/* Set the next-arg-index to point at the non-options
			 that we previously skipped, so the caller will digest them.  */
			if (first_nonopt != last_nonopt)
				optind = first_nonopt;
			return EOF;
		}

		/* If we have come to a non-option and did not permute it,
		 either stop the scan or describe it to the caller and pass it by.  */

		if ((argv[optind][0] != '-' || argv[optind][1] == '\0')) {
			if (ordering == REQUIRE_ORDER)
				return EOF;
			optarg = argv[optind++];
			return 1;
		}

		/* We have found another option-ARGV-element.
		 Skip the initial punctuation.  */

		nextchar = (argv[optind] + 1 + (longopts != NULL && argv[optind][1] == '-'));
	}

	/* Decode the current option-ARGV-element.  */

	/* Check whether the ARGV-element is a long option.

	 If long_only and the ARGV-element has the form "-f", where f is
	 a valid short option, don't consider it an abbreviated form of
	 a long option that starts with f.  Otherwise there would be no
	 way to give the -f short option.

	 On the other hand, if there's a long option "fubar" and
	 the ARGV-element is "-fu", do consider that an abbreviation of
	 the long option, just like "--fu", and not "-f" with arg "u".

	 This distinction seems to be the most useful approach.  */

	if (longopts != NULL && (argv[optind][1] == '-' || (long_only && (argv[optind][2] || !my_index(optstring, argv[optind][1]))))) {
		char *nameend;
		const struct option *p;
		const struct option *pfound = NULL;
		int exact = 0;
		int ambig = 0;
		int indfound;
		int option_index;

		for (nameend = nextchar; *nameend && *nameend != '='; nameend++)
			/* Do nothing.  */;

		/* Test all long options for either exact match
		 or abbreviated matches.  */
		for (p = longopts, option_index = 0; p->name; p++, option_index++)
			if (!strncmp(p->name, nextchar, nameend - nextchar)) {
				if ((unsigned int) (nameend - nextchar) == (unsigned int) strlen(p->name)) {
					/* Exact match found.  */
					pfound = p;
					indfound = option_index;
					exact = 1;
					break;
				} else if (pfound == NULL) {
					/* First nonexact match found.  */
					pfound = p;
					indfound = option_index;
				} else
					/* Second or later nonexact match found.  */
					ambig = 1;
			}

		if (ambig && !exact) {
			if (opterr)
				fprintf(stderr, "%s: option `%s' is ambiguous\n", argv[0], argv[optind]);
			nextchar += strlen(nextchar);
			optind++;
			return '?';
		}

		if (pfound != NULL) {
			option_index = indfound;
			optind++;
			if (*nameend) {
				/* Don't test has_arg with >, because some C compilers don't
				 allow it to be used on enums.  */
				if (pfound->has_arg)
					optarg = nameend + 1;
				else {
					if (opterr) {
						if (argv[optind - 1][1] == '-')
							/* --option */
							fprintf(stderr, "%s: option `--%s' doesn't allow an argument\n", argv[0], pfound->name);
						else
							/* +option or -option */
							fprintf(stderr, "%s: option `%c%s' doesn't allow an argument\n", argv[0], argv[optind - 1][0], pfound->name);
					}
					nextchar += strlen(nextchar);
					return '?';
				}
			} else if (pfound->has_arg == 1) {
				if (optind < argc)
					optarg = argv[optind++];
				else {
					if (opterr)
						fprintf(stderr, "%s: option `%s' requires an argument\n", argv[0], argv[optind - 1]);
					nextchar += strlen(nextchar);
					return optstring[0] == ':' ? ':' : '?';
				}
			}
			nextchar += strlen(nextchar);
			if (longind != NULL)
				*longind = option_index;
			if (pfound->flag) {
				*(pfound->flag) = pfound->val;
				return 0;
			}
			return pfound->val;
		}

		/* Can't find it as a long option.  If this is not getopt_long_only,
		 or the option starts with '--' or is not a valid short
		 option, then it's an error.
		 Otherwise interpret it as a short option.  */
		if (!long_only || argv[optind][1] == '-' || my_index(optstring, *nextchar) == NULL) {
			if (opterr) {
				if (argv[optind][1] == '-')
					/* --option */
					fprintf(stderr, "%s: unrecognized option `--%s'\n", argv[0], nextchar);
				else
					/* +option or -option */
					fprintf(stderr, "%s: unrecognized option `%c%s'\n", argv[0], argv[optind][0], nextchar);
			}
			nextchar = (char *) "";
			optind++;
			return '?';
		}
	}

	/* Look at and handle the next short option-character.  */

	{
		char c = *nextchar++;
		char *temp = my_index(optstring, c);

		/* Increment `optind' when we start to process its last character.  */
		if (*nextchar == '\0')
			++optind;

		if (temp == NULL || c == ':') {
			if (opterr) {
				if (posixly_correct)
					/* 1003.2 specifies the format of this message.  */
					fprintf(stderr, "%s: illegal option -- %c\n", argv[0], c);
				else
					fprintf(stderr, "%s: invalid option -- %c\n", argv[0], c);
			}
			optopt = c;
			return '?';
		}
		if (temp[1] == ':') {
			if (temp[2] == ':') {
				/* This is an option that accepts an argument optionally.  */
				if (*nextchar != '\0') {
					optarg = nextchar;
					optind++;
				} else
					optarg = NULL;
				nextchar = NULL;
			} else {
				/* This is an option that requires an argument.  */
				if (*nextchar != '\0') {
					optarg = nextchar;
					/* If we end this ARGV-element by taking the rest as an arg,
					 we must advance to the next element now.  */
					optind++;
				} else if (optind == argc) {
					if (opterr) {
						/* 1003.2 specifies the format of this message.  */
						fprintf(stderr, "%s: option requires an argument -- %c\n", argv[0], c);
					}
					optopt = c;
					if (optstring[0] == ':')
						c = ':';
					else
						c = '?';
				} else
					/* We already incremented `optind' once;
					 increment it again when taking next ARGV-elt as argument.  */
					optarg = argv[optind++];
				nextchar = NULL;
			}
		}
		return c;
	}
}

int getopt(argc, argv, optstring)
	int argc;char * const *argv;const char *optstring; {
	return _getopt_internal(argc, argv, optstring, (const struct option *) 0, (int *) 0, 0);
}

#endif	/* _LIBC or not __GNU_LIBRARY__.  */

#ifdef TEST

/* Compile with -DTEST to make an executable for use in testing
 the above definition of `getopt'.  */

int
main (argc, argv)
int argc;
char **argv;
{
	int c;
	int digit_optind = 0;

	while (1)
	{
		int this_option_optind = optind ? optind : 1;

		c = getopt (argc, argv, "abc:d:0123456789");
		if (c == EOF)
		break;

		switch (c)
		{
			case '0':
			case '1':
			case '2':
			case '3':
			case '4':
			case '5':
			case '6':
			case '7':
			case '8':
			case '9':
			if (digit_optind != 0 && digit_optind != this_option_optind)
			printf ("digits occur in two different argv-elements.\n");
			digit_optind = this_option_optind;
			printf ("option %c\n", c);
			break;

			case 'a':
			printf ("option a\n");
			break;

			case 'b':
			printf ("option b\n");
			break;

			case 'c':
			printf ("option c with value `%s'\n", optarg);
			break;

			case '?':
			break;

			default:
			printf ("?? getopt returned character code 0%o ??\n", c);
		}
	}

	if (optind < argc)
	{
		printf ("non-option ARGV-elements: ");
		while (optind < argc)
		printf ("%s ", argv[optind++]);
		printf ("\n");
	}

	exit (0);
}

#endif /* TEST */

qftp.c：

/***************************************************************************/
/*									   */
/* qftp.c - command line driven ftp file transfer program		   */
/* Copyright (C) 1996-2001 Thomas Pfau, pfau@eclipse.net		   */
/*	1407 Thomas Ave, North Brunswick, NJ, 08902			   */
/*									   */
/* This program is free software; you can redistribute it and/or    	   */
/* modify it under the terms of the GNU General Public License		   */
/* as published by the Free Software Foundation; either version 2	   */
/* of the License, or (at your option) any later version.		   */
/*		   							   */
/* This program is distributed in the hope that it will be useful,	   */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of	   */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the	   */
/* GNU General Public License for more details. 			   */
/*							   		   */
/* You should have received a copy of the GNU General Public License	   */
/* along with this progam; if not, write to the Free Software  		   */
/* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA		   */
/* 02111-1307, USA.							   */
/*									   */
/***************************************************************************/

#if defined(__unix__) || defined(__VMS)
#include <unistd.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#if defined(_WIN32)
#include <winsock.h>
#include <io.h>
#include "getopt.h"
#endif
#if defined(VAX)
#include "getopt.h"
#endif

#include "ftplib.h"

#if !defined(S_ISDIR)
#define S_ISDIR(m) ((m&S_IFMT) == S_IFDIR)
#endif

/* exit values */
#define EX_SYNTAX 2 	/* command syntax errors */
#define EX_NETDB 3	/* network database errors */
#define EX_CONNECT 4	/* network connect errors */
#define EX_LOGIN 5	/* remote login errors */
#define EX_REMCMD 6	/* remote command errors */
#define EX_SYSERR 7	/* system call errors */

#define FTP_SEND 1	/* send files */
#define FTP_GET 2	/* retreive files */
#define FTP_DIR 3	/* verbose directory */
#define FTP_RM 4	/* delete files */
#define FTP_LIST 5	/* terse directory */

#define DIRBUF_SIZE 1024 /* for wildcard processing */

static int logged_in = 0;
static char *host = NULL;
static char *user = NULL;
static char *pass = NULL;
static char mode = 'I';
static int action = 0;
static char *invocation;
static netbuf *conn = NULL;
static int wildcard = 0;

void usage(void) {
	printf("usage:  %s <host>\n"
			"\t[ -l user [ -p pass ] ]  defaults to anonymous/user@hostname\n"
			"\t[\n"
			"\t  [ -v level ]        debug level\n"
			"\t  [ -r rootpath ]     chdir path\n"
			"\t  [ -m umask ]        umask for created files\n"
			"\t  [ -a | -i ] ]       ascii/image transfer file\n"
			"\t  [ -w ]              toggle wildcard mode\n"
			"\t  [ file ]            file spec for directory or file to transfer\n"
			"\t]...\n\n"
			"If no files are specified on command line, the program\n"
			"will read file names from stdin.\n", invocation);
}

void ftp_connect(void) {
	if (conn)
		return;
	if (host == NULL) {
		fprintf(stderr, "Host name not specified\n");
		usage();
		exit(EX_SYNTAX);
	}
	if (!logged_in) {
		if (user == NULL) {
			user = "anonymous";
			if (pass == NULL) {
				char *u, h[64];
				u = getenv("USER");
				if (gethostname(h, 64) < 0) {
					perror("gethostname");
					exit(EX_NETDB);
				}
				if ((u != NULL) && (h != NULL)) {
					static char xxx[64];
					sprintf(xxx, "%s@%s", u, h);
					pass = xxx;
				}
			}
		} else if (pass == NULL)
#if defined(_WIN32) || defined(VMS)
			exit(EX_LOGIN);
#else
		if ((pass = getpass("Password: ")) == NULL)
		exit(EX_SYSERR);
#endif
		if (!FtpConnect(host, &conn)) {
			fprintf(stderr, "Unable to connect to node %s\n%s", host, ftplib_lastresp);
			exit(EX_CONNECT);
		}
		if (!FtpLogin(user, pass, conn)) {
			fprintf(stderr, "Login failure\n%s", FtpLastResponse(conn));
			exit(EX_LOGIN);
		}
		logged_in++;
	}
}

void change_directory(char *root) {
	ftp_connect();
	if (!FtpChdir(root, conn)) {
		fprintf(stderr, "Change directory failed\n%s", FtpLastResponse(conn));
		exit(EX_REMCMD);
	}
}

struct REMFILE {
	struct REMFILE *next;
	int fsz;
	char *fnm;
};

static int log_progress(netbuf *ctl, int xfered, void *arg) {
	struct REMFILE *f = (struct REMFILE *) arg;
	int pct = (xfered * 100) / f->fsz;
	printf("%s %3d%%\r", f->fnm, pct);
	fflush(stdout);
	return 1;
}

void process_file(char *fnm) {
	int sts = 0;
	int fsz;
	struct REMFILE *filelist = NULL;
	struct REMFILE rem;

	ftp_connect();
	FtpOptions(FTPLIB_CALLBACK, (long) NULL, conn);
	if ((action == FTP_SEND) || (action == FTP_GET)) {
		if (action == FTP_SEND) {
			struct stat info;
			if (stat(fnm, &info) == -1) {
				perror(fnm);
				return;
			}
			if (S_ISDIR(info.st_mode)) {
				if (!ftpMkdir(fnm))
					fprintf(stderr, "mkdir %s failed\n%s", fnm, FtpLastResponse(conn));
				else if (ftplib_debug)
					fprintf(stderr, "Directory %s created\n", fnm);
				return;
			}
			fsz = info.st_size;
		} else {
			if (!wildcard) {
				struct REMFILE *f;
				f = (struct REMFILE *) malloc(sizeof(struct REMFILE));
				memset(f, 0, sizeof(struct REMFILE));
				f->next = filelist;
				filelist = f;
				f->fnm = strdup(fnm);
			} else {
				netbuf *dir;
				char *buf;
				if (!FtpAccess(fnm, FTPLIB_DIR, FTPLIB_ASCII, conn, &dir)) {
					fprintf(stderr, "error requesting directory of %s\n%s\n", fnm, FtpLastResponse(conn));
					return;
				}
				buf = (char *)malloc(DIRBUF_SIZE);
				while (FtpRead(buf, DIRBUF_SIZE, dir) > 0) {
					struct REMFILE *f;
					char *p;
					f = (struct REMFILE *) malloc(sizeof(struct REMFILE));
					memset(f, 0, sizeof(struct REMFILE));
					f->next = filelist;
					p = strchr(buf, '\n');
					if (p)
						*p = '\0';
					f->fnm = strdup(buf);
					filelist = f;
				}
				free(buf);
				FtpClose(dir);
			}
		}
	}
	switch (action) {
	case FTP_DIR:
		sts = FtpDir(NULL, fnm, conn);
		break;
	case FTP_LIST:
		sts = FtpNlst(NULL, fnm, conn);
		break;
	case FTP_SEND:
		rem.next = NULL;
		rem.fnm = fnm;
		rem.fsz = fsz;
		fsz /= 10;
		if (fsz > 100000)
			fsz = 100000;
		if (ftplib_debug && fsz) {
			FtpOptions(FTPLIB_CALLBACK, (long) log_progress, conn);
			FtpOptions(FTPLIB_IDLETIME, (long) 1000, conn);
			FtpOptions(FTPLIB_CALLBACKARG, (long) &rem, conn);
			FtpOptions(FTPLIB_CALLBACKBYTES, (long) fsz, conn);
		}
		sts = FtpPut(fnm, fnm, mode, conn);
		if (ftplib_debug && sts)
			printf("%s sent\n", fnm);
		break;
	case FTP_GET:
		while (filelist) {
			struct REMFILE *f = filelist;
			filelist = f->next;
			if (!FtpSize(f->fnm, &fsz, mode, conn))
				fsz = 0;
			f->fsz = fsz;
			fsz /= 10;
			if (fsz > 100000)
				fsz = 100000;
			if (ftplib_debug && fsz) {
				FtpOptions(FTPLIB_CALLBACK, (long) log_progress, conn);
				FtpOptions(FTPLIB_IDLETIME, (long) 1000, conn);
				FtpOptions(FTPLIB_CALLBACKARG, (long) f, conn);
				FtpOptions(FTPLIB_CALLBACKBYTES, (long) fsz, conn);
			}
			sts = FtpGet(f->fnm, f->fnm, mode, conn);
			if (ftplib_debug && sts)
				printf("%s retrieved\n", f->fnm);
			free(f->fnm);
			free(f);
		}
		break;
	case FTP_RM:
		while (filelist) {
			struct REMFILE *f = filelist;
			filelist = f->next;
			sts = FtpDelete(f->fnm, conn);
			if (ftplib_debug && sts)
				printf("%s deleted\n", f->fnm);
			free(f->fnm);
			free(f);
		}
		break;
	}
	if (!sts)
		printf("ftp error\n%s\n", FtpLastResponse(conn));
	return;
}

void set_umask(char *m) {
	char buf[80];
	sprintf(buf, "umask %s", m);
	ftp_connect();
	FtpSite(buf, conn);
}

int main(int argc, char *argv[]) {
	int files_processed = 0;
	int opt;

	invocation = argv[0];
	optind = 1;
	if (strstr(argv[0], "send") != NULL)
		action = FTP_SEND;
	else if (strstr(argv[0], "get") != NULL)
		action = FTP_GET;
	else if (strstr(argv[0], "dir") != NULL)
		action = FTP_DIR;
	else if (strstr(argv[0], "list") != NULL)
		action = FTP_LIST;
	else if (strstr(argv[0], "rm") != NULL)
		action = FTP_RM;
	if ((action == 0) && (argc > 2)) {
		if (strcmp(argv[1], "send") == 0)
			action = FTP_SEND;
		else if (strcmp(argv[1], "get") == 0)
			action = FTP_GET;
		else if (strcmp(argv[1], "dir") == 0)
			action = FTP_DIR;
		else if (strcmp(argv[1], "list") == 0)
			action = FTP_LIST;
		else if (strcmp(argv[1], "rm") == 0)
			action = FTP_RM;
		if (action)
			optind++;
	}
	if (action == 0) {
		usage();
		exit(EX_SYNTAX);
	}

	FtpInit();

	while (argv[optind] != NULL) {
		if (argv[optind][0] != '-') {
			if (host == NULL)
				host = argv[optind++];
			else {
				files_processed++;
				process_file(argv[optind++]);
			}
			continue;
		}
		opt = getopt(argc, argv, "ail:m:p:r:v:w");
		switch (opt) {
		case '?':
			usage();
			exit(EX_SYNTAX);
		case ':':
			usage();
			exit(EX_SYNTAX);
		case 'a':
			mode = 'A';
			break;
		case 'i':
			mode = 'I';
			break;
		case 'l':
			user = optarg;
			break;
		case 'm':
			set_umask(optarg);
			break;
		case 'p':
			pass = optarg;
			break;
		case 'r':
			change_directory(optarg);
			break;
		case 'v':
			if (opt == ':')
				ftplib_debug++;
			else
				ftplib_debug = atoi(optarg);
			break;
		case 'w':
			wildcard = !wildcard;
			break;
		default:
			usage();
			exit(EX_SYNTAX);
		}
	}

	if (files_processed == 0) {
		ftp_connect();
		if ((action == FTP_DIR) || (action == FTP_LIST))
			process_file(NULL);
		else {
			char fnm[256];
			do {
				char *nl;
				if (isatty(fileno(stdin)))
					printf("file> ");
				if (fgets(fnm, sizeof(fnm), stdin) == NULL)
					break;
				if ((nl = strchr(fnm, '\n')) != NULL)
					*nl = '\0';
				process_file(fnm);
			} while (1);
		}
	}
	if (conn)
		FtpClose(conn);
	return 0;
}

用FileZilla在本地搭建服务器，建好用户后，通过VS2010连上去，命令行参数如下：

list 127.0.0.1  -l yang -p yang 

用户名和密码都是yang。

发现了一个问题，中文会出现乱码，recv的时候就是乱码了，暂时不知道怎么解决，留到以后去解决。

在cmd里用ftp命令，也是乱码。