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Top Forums UNIX for Dummies Questions & Answers int open(const char *pathname, int flags, mode_t mode) doubt...
# 1  
Old 11-15-2007
int open(const char *pathname, int flags, mode_t mode) doubt...

hello everybody!

I want to create a file with permissions for read, write, and execute to everybody using C, so I write this code:

Code:
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(){
   int fileDescriptor;
   fileDescriptor = open("./NewFile", O_CREAT, S_IRWXU|S_IRWXG|S_IRWXO );
   printf("File Descriptor: %d\n", fileDescriptor);
   close(fileDescriptor);

   return 0;
}

I expected to have the following result:

$ ls -l NewFile
-rwxrwxrwx 1 csnmgeek csnmgeek 0 2007-11-15 09:23 NewFile

but instead I got this:

$ ls -l NewFile
-rwxr-xr-x 1 csnmgeek csnmgeek 0 2007-11-15 09:23 NewFile

Can you tell me where is the problem?
regards
jorge
# 2  
Old 11-15-2007
Where you have O_CREAT:

from the open man page:
Quote:
Exactly one of the O_RDONLY, O_WRONLY, or O_RDWR flags must be used in
composing the value of oflag. If none or more than one is used, the
behavior is undefined.
You are seeing undefined behavior.
# 3  
Old 11-15-2007
thanks you are right!
Also the permissions depends on the umask... the umask of my system is set to 0022... I have notice that a few minutes ago......

regards
jorge
 

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