Numeric file modes

[Kris Spander]

Hello,

A friend suggested that I ask you guys. Is there an easy way to get a file's permission in numeric form rather than rw-rw-rw-?
I am trying to use a case inside a script and the symbolic forms are such a pain. Anybody know an easy method?

Thanks, Kris

[A. Clay Stephenson · Accepted solution]

Hi Kris:

Can you say 'Perl'?

Try this 60-second quickie:

#!/usr/bin/perl -w

use strict;

my $i = 0;
while ($i <= $#ARGV)
{
my $mode = (stat($ARGV[$i]))[2];
printf("%s\t%03o\n",$ARGV[$i],$mode & 0777);
++$i;
}

That should do it. We are taking a slice (the 3rd element) from the stat function.

For each argument on the command line, you get a filename and the octal permissions.

[Rodney Hills]

Using perl-

perl -e '$file= ; chomp $file; @x=stat $file ; printf "%4o\n",$x[2]'

Run this and enter in the filename and it will display in octal the permissions.

I wrote this so it could be used as a filter program.

-- Rod Hills

[harry d brown jr]

#!/usr/bin/perl
use File::Find;
{
$filename = $ARGV[0];
finddepth(\&wanted,"$filename");
}
sub wanted {
my ($dev,$ino,$mode,$nlink,$uid,$gid);
if ((($f_dev,$f_ino,$f_mode,$f_nlink,$f_uid,$f_gid,$f_rdev,$f_size,$f_at
ime,$f_mtime,$f_ctime,$f_blksize,$f_blocks) = lstat($_))) {
$f_filetype = substr(sprintf("%6.6o",$f_mode),0,2);
$f_filemode = substr(sprintf("%6.6o",$f_mode),2,4);
printf("%d:%s:%s:%d:%d:%d:%d:%d:%d:%d:%d:%d:%s\n",$f_ino,$f_filetype,
$f_filemode,$f_uid,$f_gid,$f_rdev,$f_size,$f_atime,$f_mtime,$f_ctime,$f_blksize,
$f_blocks,$File::Find::name);
}
}


from http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0xcf7650011d20d6118ff40090279cd0f9,00.html

+mode +wanted


live free or die
harry

[Kris Spander]

That was quick. I got 3 answers in about 10 minutes!!

I used Clay's answer because it displayed just what I needed. Rodney's solution displays 6 digits and I only wanted the last 3 digits. Harry's was more than I needed.

Thanks very much, Kris

[Martin Johnson]

Show how grateful you are by assigning points!


:-)
Marty

[Kris Spander]

Hello again,

I need help with a small change. I would really like this to print separate digits for "owner","group", and "other". If I do this command "perms user1.dat", the script displays "user1.dat 664". I would like it to display "user1.dat 6 6 4". I know I could do this with cut but I would rather do this directly in the perms perl program because I need to process thousands of files. This is probably easy for a perl programmer but I can't seem to get it to work. Please help.

Thanks, Kris

[A. Clay Stephenson]

Hi Kris:

I assume that you are probably doing something like this in the shell in some sort of loop:

echo "${FNAME}" | perms.pl read FILENAME OWNER GROUP OTHER

You would like for me to make life easier for you. Well, it is simple:

Change:
printf("%s\t%03o\n",$ARGV[$i],$mode & 0777);
To:
printf("%s\t%o\t%o\t%o\n",
$ARGV[$i],($mode & 0700) >> 6,
($mode & 070) >> 3,($mode & 07));

The >> 6 bit-shifts the operand 6 bits (2 octal digits) to the right. I could have divided by 0100 but the bit-shift is more elegant, don't you think?

If I haven't made a typo, that should fix you. I left as separators but you could replace them with spaces if you like.

P.S. O'reilly has some excellent Perl books. Look for the ones with camels on the cover.

Regards, Clay

[Rodney Hills]

change Clay's

printf("%s\t%03o\n",$ARGV[$i],$mode & 0777);

to

@x=split(//,sprintf("%03",$mode & 0777));
printf "%s\t%s\n",$ARGV[$i],join(" ",@x);

-- Rod Hills