Hello!

I'm trying to use the mkfifo function from the POSIX module. I'm seeing inconsitencies with how it implements the 'mode' portion of the command.

If I use a mode of 0444 or 0555, then mkfifo behaves exactly as expected - the pipe is create with perms of 0444 or 055. However, if I use mkfifo with a mode of 0666 or 0777, then it doesn't work as expected.

Using a mode of 0666 actually creates a pipe with 0644. Using a mode of 0777 creates a pipe with 0755.

Is this a bug? Or is it just some behaviour that I don't understand?

Below is an illustration of what I'm seeing.

Perl version 5.8.8 on Kubuntu linux.

Thanks!

hmcm@helen:~$ perl -e 'use POSIX; mkfifo("four", 0444);'
hmcm@helen:~$ ls -l four
pr--r--r-- 1 hmcm hmcm 0 2007-10-25 13:33 four

hmcm@helen:~$ perl -e 'use POSIX; mkfifo("five", 0555);'
hmcm@helen:~$ ls -l five
pr-xr-xr-x 1 hmcm hmcm 0 2007-10-25 13:34 five

hmcm@helen:~$ perl -e 'use POSIX; mkfifo("six", 0666);'
hmcm@helen:~$ ls -l six
prw-r--r-- 1 hmcm hmcm 0 2007-10-25 13:35 six

hmcm@helen:~$ perl -e 'use POSIX; mkfifo("seven", 0777);'
hmcm@helen:~$ ls -l seven
prwxr-xr-x 1 hmcm hmcm 0 2007-10-25 13:36 seven

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In reply to bug in POSIX mkfifo? by Anonymous Monk

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