[prev in list] [next in list] [prev in thread] [next in thread] 

List:       aix-l
Subject:    Why is this not working under AIX 4.x
From:       Mario Dupuis <Mario.Dupuis () MFG ! CANADAIR ! CA>
Date:       1998-03-31 20:04:55
[Download RAW message or body]


Anyone knows why this piece of code is working under AIX 3.2.5
and not 4.1.5

I use this to test file locking related problems ...

It try's to get a lock and then reads the first 10 char of
a file called testfile.

Under 3.2.5 it works ...

But under AIX 4.1.5

it stops with this error

      Error in lockf : Bad file number

                        --------------------

#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>

main()
{     int  fd, n;
      char buff[10];

      if ((fd = open("testfile",O_EXCL)) < 0)
        fprintf(stderr,"can't open testfile\n");

      lseek(fd, 0, 0);    /*  rewind before lockf  */
                          /*  0 : lock entire file */

      if (lockf(fd,F_LOCK,0) == -1) {
         fprintf(stderr,"can't F_LOCK\n");
         perror("Error in lockf ");
      }

      if ((n = read(fd, buff, 10)) <= 0)
         fprintf(stderr,"read error\n");

      if ((write(1,buff, n)) != n)
         fprintf(stderr,"write error on stdout\n");

      lseek(fd, 0, 0);
      if (lockf(fd,F_ULOCK,0) == -1)
         fprintf(stderr,"can't F_ULOCK\n");

      close(fd);
}

--

+---------------------------------------------------------------------+
| Mailto: Mario.Dupuis@mfg.canadair.ca  Phone : (514) 855-5001 #51720 |
| System Administrator/BAG                Fax : (514) 855-2157        |
|            Hiroshima 45 -- Chernobyl 86 -- Windows 95               |
+---------------------------------------------------------------------+

[prev in list] [next in list] [prev in thread] [next in thread]