Directory, file and permissions

 

Compiler: Visual C++ Express Edition 2005

Compiled on Platform: Windows XP Pro SP2

Header file: Standard

Additional library: none/default

Additional project setting: Set project to be compiled as C

Project -> your_project_name Properties -> Configuration Properties -> C/C++ -> Advanced -> Compiled As: Compiled as C Code (/TC)

Other info: none

To do: Playing with some of the file handling functions

To show: Directory, file, access right and permissions

 

/* Using the file handling functions */

#include <io.h>

#include <stdio.h

#include <stdlib.h>

#include <sys.h>

 

/* You can try other files and directories */

char obj[50] = "e:\\testfolder\\robots.txt";

char newobj[50] = "e:\\testfolder\\human.txt";

 

int main(void)

{

int result;

 

/* Check for existence */

printf("Check the file existence...\n");

if((_access(obj, 0)) != -1)

printf("%s file exists\n", obj);

else

printf("%s file does not exist lol!\n", obj);

 

/* Check for read/write permission */

printf("\nCheck for read/write permission...\n");

if((_access(obj, 2)) != -1)

printf("%s file has write permission\n", obj);

if((_access(obj, 4)) != -1)

printf("%s file has read permission\n", obj);

if((_access(obj, 6)) != -1)

printf("%s file has write and read permission\n\n", obj);

 

/* Make a file read-only */

printf("\nMake file read-only...\n");

 

if(_chmod(obj, _S_IREAD) == -1)

perror("File not found lol!");

else

{

printf("The file mode is changed to read-only\n");

_chmod(obj, _S_IREAD);

}

if((_access(obj, 4)) != -1)

printf("%s file has read permission\n", obj);

 

/* Change back to read/write */

printf("\nChange back to read/write...\n");

if(_chmod(obj, _S_IWRITE) == -1)

perror("file not found lol!");

else

{

printf("The file\'s mode is changed to read/write\n");

_chmod(obj, _S_IWRITE);

}

if((_access(obj, 2)) != -1)

printf("%s file has write permission\n", obj);

 

/* Attempt to rename the file */

printf("\nAttempt to rename the file...\n");

result = rename(obj, newobj);

if(result != 0)

printf("Could not rename %s\n", obj);

else

printf("%s file has been renamed to\n %s\n", obj, newobj);

 

/* remove the created file */

printf("\nRemoving the created file...\n");

if(remove(newobj) == -1)

printf("Could not delete %s lol!\n", newobj);

else

printf("Ooops! %s file has been deleted lol!\n", newobj);

return 0;

}

 

Output example (when the file does not exist):

 

 

Check the file existence...

e:\testfolder\robots.txt file does not exist lol!

Check for read/write permission...

Make file read-only...

File not found lol!: No such file or directory

Change back to read/write...

file not found lol!: No such file or directory

Attempt to rename the file...

Could not rename e:\testfolder\robots.txt

Removing the created file...

Could not delete e:\testfolder\human.txt lol!

Press any key to continue . . .

 

 

Output example (when the file is exist):

 

 

Check the file existence...

e:\testfolder\robots.txt file exists

Check for read/write permission...

e:\testfolder\robots.txt file has write permission

e:\testfolder\robots.txt file has read permission

e:\testfolder\robots.txt file has write and read permission

 

Make file read-only...

The file mode is changed to read-only

e:\testfolder\robots.txt file has read permission

Change back to read/write...

The file's mode is changed to read/write

e:\testfolder\robots.txt file has write permission

Attempt to rename the file...

e:\testfolder\robots.txt file has been renamed to

e:\testfolder\human.txt

Removing the created file...

Ooops! e:\testfolder\human.txt file has been deleted lol!

Press any key to continue . . .

 

 

C and C++ Programming Resources | C & C++ Code Example Index