Re: not wanting to delete somebody's home directory
On 7/5/19 8:24 AM, mick crane wrote:
hello, I doing some code in perl and I'm not very good at it. code
makes some images and saves them to a directory. If the directory
doesn't exist it gets made and if it does exist all the files in it
get deleted before putting some new ones in. I'm thinking that if I
ever give it to somebody it's possible they might call the directory
"~/" or something and end up deleting all their files, which I'd like
to avoid. How would that best be avoided ? Is that something to do
with chroot which I don't know anything about.
On 7/5/19 8:32 AM, mick crane wrote:
after they get made I rename them all in consecutive order and if
there's other files in there the number order will get messed up.
On 7/5/19 8:38 AM, mick crane wrote:> I guess the safest thing would be
to keep making new directories called
the current time and only delete things by hand but still would be
interested if there is a solution.
On 7/5/19 10:39 AM, mick crane wrote:
I'm incrementing the number by the loop and some software sees 2 as
bigger that 10 or something like this. I can probably get around that
by adding to a very large number in the loop and calling them that. I
don't mind deleting them by hand but if I have to run program
several times to tweak what images look like it slows things down. I
was interested though if there was some instruction to put at the
top of the file to make perl think that the directory the file was in
was "/"
On 7/5/19 10:56 AM, mick crane wrote:
Ah Ok, I could assert a directory and then the output directory make
that a subdirectory. so if they typed "~/" "./images_out/~/" would
cause an error ?
On 7/5/19 11:59 AM, mick crane wrote:
a directory called "~/" might be tricky to delete ?
Here are some ideas regarding what to do if files already exist in the
destination directory:
1. Prompt the user before deleting each file.
2. Prompt the user once before deleting all files.
3. Provide "--yes" and "--no" command line options for pre-answering
prompts.
4. Provide a "--force" option that deletes all files without prompting.
If you are serious about programming in Perl, you should buy the Perl
Cookbook:
http://shop.oreilly.com/product/9780596003135.do
https://www.oreilly.com/library/view/perl-cookbook/1565922433/ch09s03.html
https://www.oreilly.com/library/view/perl-cookbook/1565922433/ch15s02.html
A demo script and command line session follow.
David
2019-07-05 13:17:45 dpchrist@tinkywinky ~/sandbox/perl
$ cat prompt-delete-file.pl
#!perl
# $Header: /var/local/cvs/dpchrist/sandbox/perl/prompt-delete-file.pl,v
1.3 2019/07/05 20:17:44 dpchrist Exp $
# Demonstrate command-line option and interactive prompt
# by David Paul Christensen dpchrist@holgerdanske.com
# Public Domain
use strict;
use warnings;
use File::Slurp;
use Getopt::Long;
sub prompt
{
print "@_? ";
return <STDIN>;
}
### main
{
my $f = $0 . '.tmp';
my %opt;
GetOptions \%opt, 'force';
unless (-f $f) {
warn "Writing $f\n";
write_file $f, "hello, world!\n";
}
if ($opt{force} || prompt("Remove '$f' (y/N)") =~ /y/i) {
warn "Unlinking $f\n";
unlink $f or die "unlink $f: $!";
}
}
2019-07-05 13:17:59 dpchrist@tinkywinky ~/sandbox/perl
$ perl prompt-delete-file.pl
Writing prompt-delete-file.pl.tmp
Remove 'prompt-delete-file.pl.tmp' (y/N)?
2019-07-05 13:18:08 dpchrist@tinkywinky ~/sandbox/perl
$ cat prompt-delete-file.pl.tmp
hello, world!
2019-07-05 13:18:13 dpchrist@tinkywinky ~/sandbox/perl
$ perl prompt-delete-file.pl
Remove 'prompt-delete-file.pl.tmp' (y/N)? y
Unlinking prompt-delete-file.pl.tmp
2019-07-05 13:18:19 dpchrist@tinkywinky ~/sandbox/perl
$ cat prompt-delete-file.pl.tmp
cat: prompt-delete-file.pl.tmp: No such file or directory
2019-07-05 13:18:21 dpchrist@tinkywinky ~/sandbox/perl
$ perl prompt-delete-file.pl --force
Writing prompt-delete-file.pl.tmp
Unlinking prompt-delete-file.pl.tmp
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