linux用C如何判断一个目录是否为空

下面的程序在solaris8、gcc编译通过的，如果一个目录是空的，输出为2。

QUOTE: #include #include #include int main(int argc , char **argv){DIR *dirpint num=0dirp = opendir(argv[1])

while (dirp) {

if ( readdir(dirp) != NULL)++numelsebreak}closedir(dirp)

printf("%d\n",num)

}shell中判断目录为空

1. shell判断文件,目录是否存在或者具有权限

2. #!/bin/sh

3.

4. myPath="/var/log/httpd/"

5. myFile="/var /log/httpd/access.log"

6.

7. # 这里的-x 参数判断$myPath是否存在并且是否具有可执行权限

8. if [ ! -x "$myPath"]then

9. mkdir "$myPath"

10. fi

11.

12. # 这里的-d 参数判断$myPath是否存在

13. if [ ! -d "$myPath"]then

14. mkdir "$myPath"

15. fi

16.

17. # 这里的-f参数判断$myFile是否存在

18. if [ ! -f "$myFile" ]then

19. touch "$myFile"

20. fi

21.

22. # 其他参数还有-n,-n是判断一个变量是否是否有值

23. if [ ! -n "$myVar" ]then

24. echo "$myVar is empty"

25. exit 0

26. fi

27.

28. # 两个变量判断是否相等

29. if [ "$var1" = "$var2" ]then

30. echo '$var1 eq $var2'

31. else

32. echo '$var1 not eq $var2'

33. fi

-f 和-e的区别

Conditional Logic on Files

-a file exists.

-b file exists and is a block special file.

-c file exists and is a character special file.

-d file exists and is a directory.

-e file exists (just the same as -a).

-f file exists and is a regular file.

-g file exists and has its setgid(2) bit set.

-G file exists and has the same group ID as this process.

-k file exists and has its sticky bit set.

-L file exists and is a symbolic link.

-n string length is not zero.

-o Named option is set on.

-O file exists and is owned by the user ID of this process.

-p file exists and is a first in, first out (FIFO) special file or

named pipe.

-r file exists and is readable by the current process.

-s file exists and has a size greater than zero.

-S file exists and is a socket.

-t file descriptor number fildes is open and associated with a

terminal device.

-u file exists and has its setuid(2) bit set.

-w file exists and is writable by the current process.

-x file exists and is executable by the current process.

-z string length is zero.

是用 -s 还是用 -f 这个区别是很大的！

1. Shell 版本

#获取当前脚本所在绝对路径

cur_dir=$(cd "$(dirname "$0")"pwd)

2. C语言版本

方法一、用realpath函数。这种方法用于开机启动程序获取自身目录会出错

char current_absolute_path[MAX_SIZE]

//获取当前目录绝对路径

if (NULL == realpath("./", current_absolute_path))

{

printf("***Error***\n")

exit(-1)

}

strcat(current_absolute_path, "/")

printf("current absolute path:%s\n", current_absolute_path)

方法二、用getcwd函数。这种方法用于开机启动程序获取自身目录会出错

char current_absolute_path[MAX_SIZE]

//获取当前目录绝对路径

if (NULL == getcwd(current_absolute_path, MAX_SIZE))

{

printf("***Error***\n")

exit(-1)

}

printf("current absolute path:%s\n", current_absolute_path)

方法三、用readlink函数。这种方法最可靠，可用于开机启动程序获取自身目录

char current_absolute_path[MAX_SIZE]

//获取当前程序绝对路径

int cnt = readlink("/proc/self/exe", current_absolute_path, MAX_SIZE)

if (cnt <0 || cnt >= MAX_SIZE)

{

printf("***Error***\n")

exit(-1)

}

//获取当前目录绝对路径，即去掉程序名

int i

for (i = cnti >=0--i)

{

if (current_absolute_path[i] == '/')

{

current_absolute_path[i+1] = '\0'

break

}

}

printf("current absolute path:%s\n", current_absolute_path)

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