fikovnik

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

fikovnik

val G1 = List("α", "β", "γ", "δ", "ε", "ϛ", "ζ", "η", "θ")
val G10 = List("ι", "κ", "λ", "μ", "ν", "ξ", "ο", "π", "ϙ")
val G100 = List("ρ", "σ", "τ", "υ", "φ", "χ", "ψ", "ω", "ϡ")
val G1000 = List(",α", ",β", ",γ", ",δ", ",ε", ",ϛ", ",ζ", ",η", ",θ")

fikovnik

# From [[info:efaq#Colors%20on%20a%20TTY][Colors on a TTY]]
# Use colon separators.
screen-24bit|screen with 24-bit direct color mode,
  use=screen-256color,
  setb24=\E[48:2:%p1%{65536}%/%d:%p1%{256}%/%{255}%&%d:%p1%{255}%&%dm,
  setf24=\E[38:2:%p1%{65536}%/%d:%p1%{256}%/%{255}%&%d:%p1%{255}%&%dm,
# Use semicolon separators.
screen-24bits|screen with 24-bit direct color mode,
  use=screen-256color,
  setb24=\E[48;2;%p1%{65536}%/%d;%p1%{256}%/%{255}%&%d;%p1%{255}%&%dm,

fikovnik

#!/bin/sh

export CXXFLAGS="-O0 -ggdb3"
export CPPFLAGS="-O0 -ggdb3"
export CFLAGS="-O0 -ggdb3"
export R_KEEP_PKG_SOURCE=yes
export CXX="g++"

./configure --with-blas --with-lapack --without-ICU --with-x        \
            --with-tcltk --without-aqua --with-recommended-packages \

fikovnik

#!/bin/sh

export CXXFLAGS="-O2 -ggdb3"
export CPPFLAGS="-O2 -ggdb3"
export CFLAGS="-O2 -ggdb3"
export R_KEEP_PKG_SOURCE=yes
export CXX="g++"

./configure --with-blas --with-lapack --without-ICU --with-x        \
            --with-tcltk --without-aqua --with-recommended-packages \

fikovnik

"**************************************************************************
 * Allowable characters:                                                  *
 *    - a-z                                                               *
 *    - A-Z                                                               *
 *    - 0-9                                                               *
 *    - .+/\*~<>@%|&?                                                     *
 *    - blank, tab, cr, ff, lf                                            *
 *                                                                        *
 * Variables:                                                             *
 *    - variables must be declared before use                             *

fikovnik

#include <stdio.h>
#include <sys/ptrace.h>
#include <sys/reg.h>
#include <sys/wait.h>
#include <unistd.h>

int main() {
  int status;

  pid_t child_pid = fork();

fikovnik

#!/bin/bash -x

CATEGORY="audioteka"

function get_mp3_tag() {
	local file="$1"
	local tag="$2"

	ffprobe -v error -show_entries format_tags="$tag" -of default=noprint_wrappers=1:nokey=1 "$file"
}