• 0 Posts
  • 16 Comments
Joined 16 days ago
Cake day: March 13th, 2025
  • mina86@lemmy.wtftoLinux@lemmy.ml•look for symlinks pointing at the contents of directory?
    51·
    14 hours ago

    You want readlink -f rather than ls -l. ++OK, actually not exactly. readlink won’t print path to the symlink so it’s not as straightforward.++

    Also, you want + in find ... -exec ... + rather than ;.

    At this point I feel committed to making readlink work. ;) Here’s the script you want:

    #!/bin/sh

want=$1
shift
readlink -f -- "$@" | while read got; do
	if [ "$got" = "$want" ]; then
		echo "$1"
	fi
	shift
done

    and execute it as:

    find ~ -type l -exec /bin/sh /path/to/the/script /path/to/target/dir {} +
  • mina86@lemmy.wtftoLinux@lemmy.ml•today i learned: svg files are just text in an html-like languageEnglish
    31·
    8 days ago

    Another interesting part is that HTML5 supports embedding SVG. That is, you can put SVG code directly in your HTML5 document and it’s going to render correctly. You can also style it through your website’s CSS file and manipulate the elements via JavaScript.

    Though as others pointed out, it’s technically not HTML but XML. For example, you have to close all the elements and quote all the attribute values. But when you embed it inside a HTML document, those rules get relaxed to adhere with HTML. (I.e., you cannot write <circle r=5> in SVG (it must be <circle r="5" />) but you can when you embed it in HTML).

  • mina86@lemmy.wtftoLinux@lemmy.ml•Linux Terminal: CTRL+D is like pressing ENTEREnglish
    21·
    7 days ago

    Which is why I haven’t wrote ‘EOF character’, ‘EOT’ or ‘EOT character’. Neither have I claimed that \x4 character is interpreted by the shell as end of file.

    Edit: Actually, I did say ‘EOF character’ originally (though I still haven’t claimed that it sends EOF character to the program). I’ve updated the comment to clear things up more.

  • mina86@lemmy.wtftoLinux@lemmy.ml•root (or sudo) access delay instead of passwordEnglish
    12·
    8 days ago

    Sure, though I advise against it. The following C program can do that:

    #include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int main(int argc, char **argv) {
	if (argc < 2) {
		fprintf(stderr, "usage: %s <command> <args>...", argv[0]);
		return EXIT_FAILURE;
	}

	printf("Executing");
	for (int i = 1; i < argc; ++i) {
		printf(" %s", argv[i]);
	}
	puts("\nPress ^C to abort.");
	sleep(5);

	if (setuid(0)) {
		perror("setuid");
		return EXIT_FAILURE;
	}

	execvp(argv[1], argv + 1);
	perror(argv[1]);
	return EXIT_FAILURE;
}

    As seen in:

    $ gcc -O2 -o delay-su delay-su.c
$ sudo chown root:sudo delay-su
$ sudo chmod 4750 delay-su
$ ./delay-su id
$ id -u
1000
$ ./delay-su id -u
Executing id -u
^C to abort
0

    This will allow anyone in group sudo to execute any command as root. You may change the group to something else to control who exactly can run the program (you cannot change the user of the program).

    If there’s some specific command you want to run, it’s better to hard-code it or configure sudo to allow execution of that command without password.

  • mina86@lemmy.wtftoLinux@lemmy.ml•Linux Terminal: CTRL+D is like pressing ENTEREnglish
    222·
    7 days ago

    It’s not. You keep insisting that ^D doesn’t send EOF and yet:

    $ stty -a | grep eof
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
$ man stty |grep -A1 eof |head -n2
       eof CHAR
              CHAR will send an end of file (terminate the input)

    ^D (which is an ASCII EOT character) signals EOF. The thing is that in C every line of a text file must be terminated by a new-line. And so, when you end a file with ^D without a return, you get funky results.