Thread: displaying file permissions

I am having some troubles in displaying the file permissions for a file!!! ...At the moment, all it does is display the integer format for file permissions, as all i am doing is:

Code:

printf("%d", fileattrib.st_mode);

which outputs the following (along with a few other lines of output code)

Code:

list of contents for: cwd
33261   1 root     root         15343 Fri Nov 25 11:34:48 2005 myls
33188   1 root     root          7735 Fri Nov 25 11:34:43 2005 myls.c
33188   1 root     root          7131 Fri Nov 25 10:15:49 2005 myls.c~
16877   2 root     root          4096 Fri Nov 25 11:31:09 2005 test1

I need to find out how to format it so that it outputs the following for the file permissions: (output from the propper ls command using -l switch)

Code:

total 36
-rwxr-xr-x    1 root     root        15343 Nov 25 11:34 myls
-rw-r--r--    1 root     root         7735 Nov 25 11:34 myls.c
-rw-r--r--    1 root     root         7131 Nov 25 10:15 myls.c~
drwxr-xr-x    2 root     root         4096 Nov 25 11:31 test1

Anyone know how to do this??? ...i have looked around on the net, some people say to use sperm, but this wont compile, so i am stuck!!!! Cheers, matt.

Take the value of "myls" permission, it's 33261. Now convert it to octal, the value is 100755.
It's a lot easier to understand that way. Hint:

Code:

7 = 111 in binary - rwx
5 = 101 in binary - r-x
5 = 101 in binary - r-x

ah ha!!!! thankyou very very very much!!!! ...now i understand how it becomes 755!!!! cheers

Found another way that works...

Code:

struct stat fileattrib;
int fileMode;       

        /* print a leading dash as start of file/directory permissions */
        printf("-");
        fileMode = fileattrib.st_mode;
        /* Check owner permissions */
        if ((fileMode & S_IRUSR) && (fileMode & S_IREAD))
          printf("r");
        else
          printf("-");
        if ((fileMode & S_IWUSR) && (fileMode & S_IWRITE)) 
          printf("w");
        else
          printf("-");
        if ((fileMode & S_IXUSR) && (fileMode & S_IEXEC))
          printf("x");
        else
          printf("-");
        /* Check group permissions */
        if ((fileMode & S_IRGRP) && (fileMode & S_IREAD))
          printf("r");
        else
          printf("-");
        if ((fileMode & S_IWGRP) && (fileMode & S_IWRITE))
          printf("w");
        else
          printf("-");
        if ((fileMode & S_IXGRP) && (fileMode & S_IEXEC))
          printf("x");
        else
          printf("-");
        /* check other user permissions */
        if ((fileMode & S_IROTH) && (fileMode & S_IREAD))
          printf("r");
        else
          printf("-");
        if ((fileMode & S_IWOTH) && (fileMode & S_IWRITE))
          printf("w");
        else
          printf("-");
        if ((fileMode & S_IXOTH) && (fileMode & S_IEXEC))
          /* because this is the last permission, leave 3 blank spaces after print */
          printf("x   ");

DONE! I will stick to this because its my own code, and it works well enough for me!!!!!

LOL ...Just missed out the copy bit of the last:

Code:

else
  printf("-   );