我很新的C语言编程，并在任何地方有关于如何做的在C（不是C ++，C＃，Objective-C中，爪哇，外壳，Python或其他任何一个目录的内容递归复制几乎有用的信息 - 这必须用C来实现）。 是的，这是家庭作业，这是因为明天晚上，我一直在为被困近两个星期试图完成这件事。
我试图寻找一个给定的目录（如目录“目录”有一个备份目录“/dir.bak”）的任何备份版本。 如果没有，创建一个“/dir.bak”目录下，或者如果有，创建一个名为“/dir.bak.MM-DD-YY-HH-MM-SS”，而不是一个备份目录。 然后从源目录复制到所有的目标目录。
当我尝试运行此代码：
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/time.h>
#include <time.h>
#define BUFSIZE 256
int main (int argc, char* argv[])
{
DIR *dir;
struct dirent *dentry;
struct stat statbuff;
char buffer[BUFSIZE];//holds time and date suffix
ssize_t count;
int fdin, fdout;
mode_t perms = 740;//perms for file I/O ops
char *cwdNamePntr;
long maxpath;
if ( argc != 3 ) //if incorrect number of args passed in...
{
printf( "Usage: %s Directory-Path-Name Destination-Folder\n ", argv[0] );
exit(1);
}
char buffer2[BUFSIZE];//buffer for file I/O ops
char* datetime;
int retval;
time_t clocktime;
struct tm *timeinfo;
time (&clocktime);
timeinfo = localtime( &clocktime );
strftime(buffer, BUFSIZE, "%b-%d-%Y-%H-%M-%S", timeinfo);//store time and date suffix in case we need it
chdir(argv[1]);
char *path = argv[2];//source path for I/O ops
char *newpath = malloc(strlen(path) + 26);//destination paths for I/O ops
strcpy(newpath,path);
strcat(newpath,".bak");//test name for backup directory
if(chdir(newpath)==0)
{//if our test name is already a directory
chdir("..");
strcat(newpath,".");
strcat(newpath,buffer);//add time and date suffix onto the name of new backup directory
}
if ( (mkdir(newpath, perms)) == 0 )//if we successfully made a new backup directory
{
chdir(path);
dir = opendir(".");//move into source directory
if ( dir == 0 )
{//if open directory fails
fprintf (stderr, "Error in opening directory: %s\n", path );
perror( "Could not open directory");
exit(2);
}
dentry = readdir (dir);//load directory
while (dentry != 0)//while we are reading a directory
{
char *filename = dentry->d_name;//get name of file to be copied
if( (strcmp(filename,".")!=0) && (strcmp(filename,"..")!=0) )
{
if ( (fdin = open ( filename, O_RDONLY)) == -1)
{//if cannot open input file
perror ( "Error in opening the input file:");
exit (2);
}
chdir("..");//go back to parent directory
chdir(newpath);//move to destination directory
opendir(".");
if ( (fdout = open (filename, (O_WRONLY | O_CREAT), perms)) == -1 )
{//if cannot create output file...
perror ( "Error in creating the output file:");
exit (3);
}
while ( (count=read(fdin, buffer2, BUFSIZE)) > 0 )
{
if ( write (fdout, buffer2, count) != count )
{//if cannot write
perror ("Error in writing" );
exit(3);
}
}
if ( count == -1 )
{//if cannot read
perror ( "Error while reading the input file: ");
exit(4);
}
close(fdin);
close(fdout);
}
chdir("..");//back to parent directory again
dir = opendir(".");
if ( dir == 0 )//if open directory fails
{
fprintf (stderr, "Error in opening directory: %s\n", path );
perror( "Could not open directory");
exit(666);
}
dentry = readdir (dir);//reload directory
}
}
else
{
perror("Error in directory creation");
exit(2);
}
return 0;
}
我得到这个错误：
[my-desktop]@ubuntu:~/Desktop$ ./helpmehelpyou.out ~/Desktop new
Error in creating the output file:: Permission denied
这段代码的一堆是从我们的教官说，我们可以用样本文件拍摄。 我不明白这是为什么不工作的权利？ 成品函数必须是递归的，并与这之中选项4. C是我很难把握或理解四自选程序的一部分，就像我说的，有这个东西对C的信息非常少，但一它为过多的C＃，C ++，Objective C的，和所有其他的语言。 就像我也说了，我们可以不使用shell命令或任何其他为这项任务。
有人可以帮帮我吗？ 谢谢！
