Public
- Public
- Network
- Groups
- Popular
- People

Notices by Julia's Reruns Bot (b0rk_reruns@social.jvns.ca), page 2

Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Tuesday, 14-Feb-2023 04:04:35 JST Julia's Reruns Bot

mmap
Permalink: https://wizardzines.com/comics/mmap/
In conversation Tuesday, 14-Feb-2023 04:04:35 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'mmap'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/858/828/020/553/192/original/fb8cce51338367da.png
2. mmap
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Saturday, 11-Feb-2023 03:30:47 JST Julia's Reruns Bot

permissions
Permalink: https://wizardzines.com/comics/permissions/
In conversation Saturday, 11-Feb-2023 03:30:47 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'permissions'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/841/840/650/180/217/original/8cb6f8286747c30e.png
2. permissions
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Thursday, 09-Feb-2023 03:26:42 JST Julia's Reruns Bot

/proc
Permalink: https://wizardzines.com/comics/proc/
In conversation Thursday, 09-Feb-2023 03:26:42 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title '/proc'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/830/515/788/684/455/original/10f6580d5f5b5cc4.png
2. /proc
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Tuesday, 07-Feb-2023 03:32:14 JST Julia's Reruns Bot

page-faults
Permalink: https://wizardzines.com/comics/page-faults/
In conversation Tuesday, 07-Feb-2023 03:32:14 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'page-faults'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/819/190/626/410/798/original/3a1ee43e512185c2.png
2. page faults
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Sunday, 05-Feb-2023 03:25:03 JST Julia's Reruns Bot

file descriptors
Permalink: https://wizardzines.com/comics/file-descriptors/
In conversation Sunday, 05-Feb-2023 03:25:03 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'file descriptors'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/807/863/308/851/938/original/cf234b127b310786.png
2. file descriptors
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Friday, 03-Feb-2023 03:25:14 JST Julia's Reruns Bot

file buffering
Permalink: https://wizardzines.com/comics/file-buffering/
In conversation Friday, 03-Feb-2023 03:25:14 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'file buffering'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/796/541/317/015/190/original/f4f0f5fafa4393a1.png
2. file buffering
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Wednesday, 01-Feb-2023 03:25:09 JST Julia's Reruns Bot

man page sections
Permalink: https://wizardzines.com/comics/man-pages/
In conversation Wednesday, 01-Feb-2023 03:25:09 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'man page sections'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/785/216/428/076/599/original/8def9d6f68518b5d.png
2. man page sections
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Monday, 30-Jan-2023 03:26:13 JST Julia's Reruns Bot

system calls
Permalink: https://wizardzines.com/comics/syscalls/
In conversation Monday, 30-Jan-2023 03:26:13 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'system calls'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/773/888/611/982/691/original/32f8b88a0df63e83.png
2. system calls
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Saturday, 28-Jan-2023 03:33:08 JST Julia's Reruns Bot

virtual memory
Permalink: https://wizardzines.com/comics/virtual-memory/
In conversation Saturday, 28-Jan-2023 03:33:08 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'virtual memory'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/762/566/261/020/374/original/f27883b3929ba48e.png
2. virtual memory
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Thursday, 26-Jan-2023 03:24:58 JST Julia's Reruns Bot

signals
Permalink: https://wizardzines.com/comics/signals/
In conversation Thursday, 26-Jan-2023 03:24:58 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'signals'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/751/241/709/213/293/original/c926ea029754aba7.png
2. signals
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Tuesday, 24-Jan-2023 08:03:41 JST Julia's Reruns Bot

sockets
Permalink: https://wizardzines.com/comics/sockets/
In conversation Tuesday, 24-Jan-2023 08:03:41 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'sockets'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/740/480/056/836/131/original/ef73b6822bb1b1d4.png
2. sockets
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Sunday, 22-Jan-2023 04:44:44 JST Julia's Reruns Bot

shared libraries
Permalink: https://wizardzines.com/comics/shared-libraries/
In conversation Sunday, 22-Jan-2023 04:44:44 JST from social.jvns.ca permalink
Attachments
1. # shared libraries ## panel 1 most programs on Linux use a bunch of libraries. some popular libraries: * openssl (for SSL!) * sqlite (embedded db!) * libpcre (regular expressions!) * zlib (gzip!) * libstdc++ (C++ standard library!) ## panel 2 There are 2 ways to use any library: 1) Link it into your binary (image: box containing 3 things, code, zlib, sqlite) (arrow pointing up): big binary with lots of things! 2) Use separate shared libraries (image: 3 separate boxes: code, zlib, sqlite) (arrow): all different files ## panel 3 Programs like this (image: box containing 3 things, code, zlib, sqlite) are called "statically linked" and programs like this (image: 3 separate boxes: code, zlib, sqlite) are called "dynamically linked" ## panel 4 person 1: "how can I tell what shared libraries a program is using?" person 2: "ldd!" ``` ldd /usr/bin/curl libz.so.1 => /lib/x86_64... libresolv.so.2 =>... libc.so.6 => ``` +34 more :) ## panel 5 person 1: "I got a "library not found" error when running my binary?!" person 2: "If you know where the library is, try setting the LD_LIBRARY_PATH environment variable" dynamic linker (thinking): LD_LIBRARY_PATH tells me where to look ## panel 6 where the dynamic linker looks 1. DT_RPATH in your executable 2. LD_LIBRARY_PATH 3. DT_RUNPATH in executable 4. /etc/ld.so.cache (run ldconfig -p to see contents) 5. /lib, /usr/lib
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/728/590/326/012/337/original/9593cb2238b138bc.png
2. shared libraries
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Friday, 20-Jan-2023 08:49:54 JST Julia's Reruns Bot

processes
Permalink: https://wizardzines.com/comics/processes/
In conversation Friday, 20-Jan-2023 08:49:54 JST from social.jvns.ca permalink
Attachments
1. # what's in a process? ## PID process: "process #129, reporting for duty!" ## USER and GROUP "who are you running as?" process: "julia!" ## ENVIRONMENT VARIABLES like PATH! you can set them with: ``` env A=val ./program ``` ## SIGNAL HANDLERS process 1: "I ignore SIGTERM!" process 2: "I shut down safely!" ## WORKING DIRECTORY Relative paths (`./blah`) are relative to the working directory! `chdir` changes it. ## PARENT PID * PID 1 (init) is everyone's ancestor * (up arrow) PID 147 * (up arrow) PID 129 ## COMMAND LINE ARGUMENTS see them in `/proc/$PID/cmdline` ## OPEN FILES Every open file has an offset. process: "I've read 8000 bytes of that one" ## MEMORY heap! stack! shared libraries! the program's binary! mmaped files! ## THREADS sometimes one sometimes LOTS ## CAPABILITIES process 1: "I have CAP_PTRACE" process 2: "well I have CAP_SYS_ADMIN" ## NAMESPACES process 1: "I'm in the host network namespace" container process: "I have my own namespace!"
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/717/270/012/329/142/original/734fb6acffede380.png
2. processes
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Friday, 20-Jan-2023 08:28:09 JST Julia's Reruns Bot

unix domain sockets
Permalink: https://wizardzines.com/comics/unix-domain-sockets/
In conversation Friday, 20-Jan-2023 08:28:09 JST from social.jvns.ca permalink
Attachments
1. # unix domain sockets ## unix domain sockets are files. ``` $ file mysock.sock socket ``` the file's permissions determine who can send data to the socket. ## they let 2 programs on the same computer communicate. Docker uses Unix domain sockets, for example! process: "wget /container" (HTTP request) docker (whale): "Here you go!" ## There are 2 kinds of Unix domain sockets 1. stream: like TCP! Lets you send a continuous stream of bytes 2. datagram: like UDP! Lets you send discrete chunks of data ## advantage 1 Lets you use file permissions to restrict access to HTTP/database services! ``` chmod 600 secret.sock ``` This is why Docker uses a unix domain socket. (lock icon) process (with evil horns): "run evil permission container" linux: "permission denied" ## advantage 2 UDP sockets aren't always reliable (even on the same computer). unix domain datagram sockets are reliable! And they won't reorder packets! process: "I can send data and I *know* it'll arrive" ## advantage 3 You can send a file descriptor over a unix domain socket. Useful when handling untrusted input files! process: "here's a file I downloaded from sketchy.com" (arrow showing file being sent to video decoder, which is a sandboxed process)
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/705/944/109/537/017/original/9bce2324d6fc91cd.png
2. unix domain sockets
Julia's Reruns Bot (b0rk_reruns@social.jvns.ca)'s status on Monday, 16-Jan-2023 04:09:59 JST Julia's Reruns Bot

pipes
Permalink: https://wizardzines.com/comics/pipes/
In conversation Monday, 16-Jan-2023 04:09:59 JST from social.jvns.ca permalink
Attachments
1. A hand drawn programming comic with the title 'pipes'. Doesn't have a proper caption yet.
  https://cdn.masto.host/socialjvnsca/media_attachments/files/109/694/616/936/195/415/original/d2014bf088918f85.png
2. pipes

After

User actions

This is a bot that I (@b0rk) made to post reruns of my comics. Posts ~3x/week.Almost all of these are part of zines that you can buy at https://wizardzines.com.

Tags

(None)

ActivityPub: Remote Profile

Following 0

Followers 0

Groups 0

Statistics

User ID: 9459

Member since: 15 Jan 2023

Notices: 35

Daily average: 0

Feeds

Atom

Public

Notices by Julia's Reruns Bot (b0rk_reruns@social.jvns.ca), page 2

User actions

Following 0

Followers 0

Groups 0

Statistics

Feeds