cpp.c

在linux下使用c语言编写的一个文件拷贝的源码

#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <string.h>
#define BUFFER_SIZE 1024

int main(int argc, char **argv)
{

    int SourceFile, DestFile;
    int BytesReaded, BytesWrited;
    int status;
    char desc;
    char Buffer[BUFFER_SIZE];
    char *ptr;

    /*  Not Enough Parameters */
    if (argc != 3) {
	printf("Usage Error!:%s fromfile tofile\n\a", argv[0]);
	exit(1);
    }

    /*  Source File Not Exit */
    if (status = access(argv[1], F_OK)) {
	printf("The Source File Not Exit.\n");
	exit(1);
    }

    /*  Destination File Exit */
    if ((status = access(argv[2], F_OK)) == 0) {
	printf("The Destination File Exit.Overwrite?(y/n)\n");
	desc = getchar();
	while (desc != 'n' && desc != 'y') {
	    printf("The Destination File Exit.Overwrite?(y/n)\n");
	    desc = getchar();
	}

	if (desc == 'n')
	    exit(0);
    }
    /*  Open the Source File  */
    if ((SourceFile = open(argv[1], O_RDONLY)) == -1) {
	printf("Open %s Error:%s\n", argv[1], strerror(errno));
	exit(1);
    }

    /*  Open the Destination File   */
    if ((DestFile =
	 open(argv[2], O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR)) == -1) {
	printf("Open %s Error:%s\n", argv[2], strerror(errno));
	exit(1);
    }

    /*  Read content from the Fromfile  */
    while (BytesReaded = read(SourceFile, Buffer, BUFFER_SIZE)) {
	/*  An errot occurt when reading    */
	if ((BytesReaded == -1) && (errno != EINTR))
	    break;
	else if (BytesReaded > 0) {
	    ptr = Buffer;
	    while (BytesWrited = write(DestFile, ptr, BytesReaded)) {
		/*  An errot occurt when writing  */
		if ((BytesWrited == -1) && (errno != EINTR))
		    break;
		/*  Finish  */
		else if (BytesWrited == BytesReaded)
		    break;
	    }
	    /*  An errot occurt when writing  */
	    if (BytesWrited == -1)
		break;
	}
    }
    close(SourceFile);
    close(DestFile);
    exit(0);
}