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| author | johannst <johannst@users.noreply.github.com> | 2024-02-15 23:29:57 +0000 |
|---|---|---|
| committer | johannst <johannst@users.noreply.github.com> | 2024-02-15 23:29:57 +0000 |
| commit | bac8a5d2822835cf47175d1162030653fadd5c09 (patch) | |
| tree | 28f312a114cf95ac799daac2a2caec4b8612d84d /print.html | |
| parent | bfc5ce4bc01e5eb28969eefcc01ecfefa2601fdf (diff) | |
| download | notes-bac8a5d2822835cf47175d1162030653fadd5c09.tar.gz notes-bac8a5d2822835cf47175d1162030653fadd5c09.zip | |
deploy: 4485708c972815bbb6df7f5a228683aa855d553d
Diffstat (limited to 'print.html')
| -rw-r--r-- | print.html | 577 |
1 files changed, 308 insertions, 269 deletions
@@ -224,11 +224,11 @@ $RBUFFER # Edit buffer content right to cursor # create zle widget which adds text right of the cursor function add-text() { - RBUFFER="some text $RBUFFER" + RBUFFER="some text $RBUFFER" } zle -N add-text -bindkey "^p" add-text +bindkey "^p" add-text </code></pre> <h2 id="parameter"><a class="header" href="#parameter">Parameter</a></h2> <p>Default value:</p> @@ -362,10 +362,10 @@ option should be stored.</li> <pre><code class="language-zsh">#!/bin/zsh function test() { zparseopts -D -E -A opts f=flag o: -long: - echo "flag $flag" - echo "o $opts[-o]" - echo "long $opts[--long]" - echo "pos $1" + echo "flag $flag" + echo "o $opts[-o]" + echo "long $opts[--long]" + echo "pos $1" } test -f -o OPTION --long LONG_OPT POSITIONAL @@ -387,9 +387,9 @@ The match results can be accessed via the <code>$MATCH</code> variable and <pre><code class="language-zsh">INPUT='title foo : 1234' REGEX='^title (.+) : ([0-9]+)$' if [[ $INPUT =~ $REGEX ]]; then - echo "$MATCH" # title foo : 1234 - echo "$match[1]" # foo - echo "$match[2]" # 1234 + echo "$MATCH" # title foo : 1234 + echo "$match[1]" # foo + echo "$match[2]" # 1234 fi </code></pre> <h2 id="completion"><a class="header" href="#completion">Completion</a></h2> @@ -421,7 +421,7 @@ $words[CURRENT-1] # previous word (relative to cursor position) </code></pre> <ul> <li><code>MSG</code> simple string with header message</li> -<li><code>COMP</code> array of completions where each entry is <code>"opt:description"</code></li> +<li><code>COMP</code> array of completions where each entry is <code>"opt:description"</code></li> </ul> <pre><code class="language-zsh">function _foo() { local -a opts @@ -462,16 +462,16 @@ function _foo_color() { colors+=('green:green color') colors+=('red:red color') colors+=('blue:blue color') - _describe "color" colors + _describe "color" colors } function _foo() { _arguments \ - "-c[define color]:color:->s_color" \ - "-s[select sound]:sound:(low high)" \ - "-f[select file]:file:_files" \ - "-d[select dir]:dir:_files -/" \ - "-h[help]" + "-c[define color]:color:->s_color" \ + "-s[select sound]:sound:(low high)" \ + "-f[select file]:file:_files" \ + "-d[select dir]:dir:_files -/" \ + "-h[help]" case $state in s_color) _foo_color;; @@ -485,9 +485,9 @@ arguments such as</p> </code></pre> <pre><code class="language-zsh">function _foo() { _arguments \ - "1:opt 1:(a b c)" \ - ":opt next:(d e f)" \ - "*:opt all:(u v w)" + "1:opt 1:(a b c)" \ + ":opt next:(d e f)" \ + "*:opt all:(u v w)" } </code></pre> <p>Explanation:</p> @@ -520,7 +520,7 @@ previous rules apply, so in our example for <code>arg3, argN..</code>.</li> bar=${foo:-some_val} # if $foo set, then bar=$foo else bar=some_val # alternate value -bar=${foo:+bla $foo} # if $foo set, then bar="bla $foo" else bar="" +bar=${foo:+bla $foo} # if $foo set, then bar="bla $foo" else bar="" # check param set bar=${foo:?msg} # if $foo set, then bar=$foo else exit and print msg @@ -602,6 +602,19 @@ contains some nice visualization to explain bash redirections.</p> once.</p> <pre><code class="language-bash">vim -d <(grep foo bar) <(grep foo moose) </code></pre> +<h2 id="command-grouping"><a class="header" href="#command-grouping">Command grouping</a></h2> +<p>Execute commands in a group with or without subshell. Can be used to easily +redirect stdout/stderr of all commands in the group into one file.</p> +<pre><code class="language-bash"># Group commands without subshell. +v=abc ; { v=foo; echo $v; } ; echo $v +# foo +# foo + +# Group commands with subshell. +v=abc ; ( v=foo; echo $v; ) ; echo $v +# foo +# abc +</code></pre> <h2 id="argument-parsing-with-getopts"><a class="header" href="#argument-parsing-with-getopts">Argument parsing with <code>getopts</code></a></h2> <p>The <code>getopts</code> builtin uses following global variables:</p> <ul> @@ -624,11 +637,11 @@ once.</p> <h3 id="example-2"><a class="header" href="#example-2">Example</a></h3> <pre><code class="language-bash">#!/bin/bash function parse_args() { - while getopts "f:c" PARAM; do + while getopts "f:c" PARAM; do case $PARAM in - f) echo "GOT -f $OPTARG";; - c) echo "GOT -c";; - *) echo "ERR: print usage"; exit 1;; + f) echo "GOT -f $OPTARG";; + c) echo "GOT -c";; + *) echo "ERR: print usage"; exit 1;; esac done # users responsibility to reset OPTIND @@ -648,14 +661,14 @@ The match results can be accessed via the <code>$BASH_REMATCH</code> variable:</ <pre><code class="language-bash">INPUT='title foo : 1234' REGEX='^title (.+) : ([0-9]+)$' if [[ $INPUT =~ $REGEX ]]; then - echo "${BASH_REMATCH[0]}" # title foo : 1234 - echo "${BASH_REMATCH[1]}" # foo - echo "${BASH_REMATCH[2]}" # 1234 + echo "${BASH_REMATCH[0]}" # title foo : 1234 + echo "${BASH_REMATCH[1]}" # foo + echo "${BASH_REMATCH[2]}" # 1234 fi </code></pre> <blockquote> <p><strong>Caution</strong>: When specifying a <code>regex</code> in the <code>[[ ]]</code> block directly, quotes will be treated as part of the pattern. -<code>[[ $INPUT =~ "foo" ]]</code> will match against <code>"foo"</code> not <code>foo</code>!</p> +<code>[[ $INPUT =~ "foo" ]]</code> will match against <code>"foo"</code> not <code>foo</code>!</p> </blockquote> <h2 id="completion-1"><a class="header" href="#completion-1">Completion</a></h2> <p>The <code>complete</code> builtin is used to interact with the completion system.</p> @@ -686,11 +699,11 @@ against words generated by <code>option</code>.</p> # -u generate list with users # -e generate list with exported variables -# compare "f" against words "foo" "foobar" "bar" and generate matches -compgen -W "foo foobar bar" "f" +# compare "f" against words "foo" "foobar" "bar" and generate matches +compgen -W "foo foobar bar" "f" -# compare "hom" against file/dir names and generate matches -compgen -d -f "hom" +# compare "hom" against file/dir names and generate matches +compgen -d -f "hom" </code></pre> <h3 id="example-3"><a class="header" href="#example-3">Example</a></h3> <p>Skeleton to copy/paste for writing simple completions.</p> @@ -702,12 +715,12 @@ compgen -d -f "hom" local curr=$2 local prev=$3 - local opts="-c -s -f -h" + local opts="-c -s -f -h" case $prev in - -c) COMPREPLY=( $(compgen -W "green red blue" -- $curr) );; - -s) COMPREPLY=( $(compgen -W "low high" -- $curr) );; + -c) COMPREPLY=( $(compgen -W "green red blue" -- $curr) );; + -s) COMPREPLY=( $(compgen -W "low high" -- $curr) );; -f) COMPREPLY=( $(compgen -f -- $curr) );; - *) COMPREPLY=( $(compgen -W "$opts" -- $curr) );; + *) COMPREPLY=( $(compgen -W "$opts" -- $curr) );; esac } @@ -774,16 +787,16 @@ echo {a,b}{1,2} with <code>:</code> when quoted or exported to the environment.</p> <pre><code class="language-sh">set -x BLA_PATH a:b:c:d echo $BLA_PATH # a b c d -echo "$BLA_PATH" # a:b:c:d (quoted) +echo "$BLA_PATH" # a:b:c:d (quoted) env | grep BLA_PATH # BLA_PATH=a:b:c:d (env) set FOO_PATH x y z echo $FOO_PATH # x y z -echo "$FOO_PATH" # x:y:z +echo "$FOO_PATH" # x:y:z </code></pre> <h2 id="command-handling"><a class="header" href="#command-handling">Command Handling</a></h2> <pre><code class="language-sh"># sub-commands are not run in quotes -echo "ls output: "(ls) +echo "ls output: "(ls) </code></pre> <h3 id="io-redirection-1"><a class="header" href="#io-redirection-1">I/O redirection</a></h3> <pre><code class="language-sh"># 'noclobber', fail if 'log' already exists @@ -852,7 +865,7 @@ funced foo # edit function 'foo' <li><a href="https://fishshell.com/docs/current/completions.html">Writing your own completions</a></li> <li><a href="https://fishshell.com/docs/current/cmds/complete.html"><code>complete</code></a></li> </ul> -<pre><code class="language-sh">function moose --d "my moose fn" +<pre><code class="language-sh">function moose --d "my moose fn" # h/help : short / long option (boolean) # color : only long option (boolean) # u/user= : option with required argument, only last specified is taken @@ -862,18 +875,18 @@ funced foo # edit function 'foo' or return if set -ql _flag_help - echo "usage ..." + echo "usage ..." return 0 end set -ql _flag_file - and echo "file=$_flag_file | cnt:" (count $_flag_file) + and echo "file=$_flag_file | cnt:" (count $_flag_file) set -ql _flag_color - and echo "color=$_flag_color" + and echo "color=$_flag_color" set -ql _flag_user - and echo "user=$_flag_user" + and echo "user=$_flag_user" end # Delete all previous defined completions for 'moose'. @@ -885,31 +898,31 @@ complete -c moose --no-files # Help completion. # -n specifies a conditions. The completion is only active if the command # returns 0. -complete -c moose -s h -l help -n "not __fish_contains_opt -s h help" \ - --description "Print usage help and exit" +complete -c moose -s h -l help -n "not __fish_contains_opt -s h help" \ + --description "Print usage help and exit" # File completion. # -F force complete files (overwrite --no-files). # -r requires argument. complete -c moose -s f -l file -F -r \ - --description "Specify file (can be passed multiple times)" + --description "Specify file (can be passed multiple times)" # Color completion. # -a options for completion. # -x short for -r and --no-files (-f) -complete -c moose -x -l color -a "red blue" \ - --description "Specify a color." +complete -c moose -x -l color -a "red blue" \ + --description "Specify a color." # User completion. # -a options for completion. Call a function to generate arguments. -complete -c moose -x -s u -l user -a "(__fish_complete_users)" \ - --description "Specify a user" +complete -c moose -x -s u -l user -a "(__fish_complete_users)" \ + --description "Specify a user" </code></pre> <h2 id="prompt"><a class="header" href="#prompt">Prompt</a></h2> <p>The prompt is defined by the output of the <code>fish_prompt</code> function.</p> <pre><code class="language-sh">function fish_prompt set -l cmd_ret - echo "> "(pwd) $cmd_ret" " + echo "> "(pwd) $cmd_ret" " end </code></pre> <blockquote> @@ -934,7 +947,7 @@ string split SEP STRING # math math -b hex 4096 # output dec as hex math 0x1000 # output hex as dec -math "log2(1024)" # call functions +math "log2(1024)" # call functions math -s0 7/3 # integer division (by default float) # status @@ -991,7 +1004,7 @@ tmux list-panes -F '#P' -t <s>:<w> list pane IDs for window <w& tmux selectp -t <s>:<w>.<p> select pane <p> in window <w> in session <s> # Run commands -tmux send -t <s>:<w>.<p> "ls" C-m send cmds/keys to pane +tmux send -t <s>:<w>.<p> "ls" C-m send cmds/keys to pane tmux run -t <p> <sh-cmd> run shell command <sh-cmd> in background and report output on pane -t <p> </code></pre> <p>For example cycle through all panes in all windows in all sessions:</p> @@ -1120,7 +1133,7 @@ list-keys -t vi-copy list keymaps for vi-copy mode branch has additional commits compared to remote branch). </code></pre> <h2 id="tags"><a class="header" href="#tags">Tags</a></h2> -<pre><code class="language-markdown"> git tag -a <tname> -m "descr" ........ creates an annotated tag (full object +<pre><code class="language-markdown"> git tag -a <tname> -m "descr" ........ creates an annotated tag (full object containing tagger, date, ...) git tag -l ........................... list available tags git checkout tag/<tname> ............. checkout specific tag @@ -1304,7 +1317,7 @@ multiple times. Actions with those patterns are <strong>executed exactly once</s <h3 id="special-statements--functions"><a class="header" href="#special-statements--functions">Special statements & functions</a></h3> <ul> <li> -<p><code>printf "fmt", args...</code></p> +<p><code>printf "fmt", args...</code></p> <p>Print format string, args are comma separated.</p> <ul> <li><code>%s</code> string</li> @@ -1317,12 +1330,12 @@ For floats one can use <code>%N.Mf</code>, <code>N</code> is the total number in <code>M</code>.</p> </li> <li> -<p><code>sprintf("fmt", expr, ...)</code></p> +<p><code>sprintf("fmt", expr, ...)</code></p> <p>Format the expressions according to the format string. Similar as <code>printf</code>, but this is a function and return value can be assigned to a variable.</p> </li> <li> -<p><code>strftime("fmt")</code></p> +<p><code>strftime("fmt")</code></p> <p>Print time stamp formatted by <code>fmt</code>.</p> <ul> <li><code>%Y</code> full year (eg 2020)</li> @@ -1356,7 +1369,7 @@ prints the whole record.</p> </code></pre> <p>Matches records not starting with <code>#</code>.</p> <h3 id="range-patterns"><a class="header" href="#range-patterns">Range patterns</a></h3> -<pre><code class="language-bash">echo -e "a\nFOO\nb\nc\nBAR\nd" | \ +<pre><code class="language-bash">echo -e "a\nFOO\nb\nc\nBAR\nd" | \ awk '/FOO/,/BAR/ { print }' </code></pre> <p><code>/FOO/,/BAR/</code> define a range pattern of <code>begin_pattern, end_pattern</code>. When @@ -1364,13 +1377,17 @@ prints the whole record.</p> <code>end_pattern</code> is matched the range is <strong>turned off</strong>. This matches every record in the range <em>inclusive</em>.</p> <p>An <em>exclusive</em> range must be handled explicitly, for example as follows.</p> -<pre><code class="language-bash">echo -e "a\nFOO\nb\nc\nBAR\nd" | \ - awk '/FOO/,/BAR/ { if (!($1 ~ "FOO") && !($1 ~ "BAR")) { print } }' +<pre><code class="language-bash">echo -e "a\nFOO\nb\nc\nBAR\nd" | \ + awk '/FOO/,/BAR/ { if (!($1 ~ "FOO") && !($1 ~ "BAR")) { print } }' </code></pre> <h3 id="access-last-fields-in-records"><a class="header" href="#access-last-fields-in-records">Access last fields in records</a></h3> <pre><code class="language-bash">echo 'a b c d e f' | awk '{ print $NF $(NF-1) }' </code></pre> <p>Access last fields with arithmetic on the <code>NF</code> number of fields variable.</p> +<h3 id="split-on-multiple-tokens"><a class="header" href="#split-on-multiple-tokens">Split on multiple tokens</a></h3> +<pre><code class="language-bash">echo 'a,b;c:d' | awk -F'[,;:]' '{ printf "1=%s | 4=%s\n", $1, $4 }' +</code></pre> +<p>Use regex as field separator.</p> <h3 id="capture-in-variables"><a class="header" href="#capture-in-variables">Capture in variables</a></h3> <pre><code class="language-bash"># /proc/<pid>/status # Name: cat @@ -1382,7 +1399,7 @@ for f in /proc/*/status; do cat $f | awk ' /^VmRSS/ { rss = $2/1024 } /^Name/ { name = $2 } - END { printf "%16s %6d MB\n", name, rss }'; + END { printf "%16s %6d MB\n", name, rss }'; done | sort -k2 -n </code></pre> <p>We capture values from <code>VmRSS</code> and <code>Name</code> into variables and print them at the @@ -1397,7 +1414,7 @@ a 1' | awk '{ } END { for (v in vals) - printf "%s %d\n", v, vals[v] / cnts [v] + printf "%s %d\n", v, vals[v] / cnts [v] }' </code></pre> <p>Capture keys and values from different columns and some up the values. @@ -1405,7 +1422,7 @@ At the <code>END</code> we compute the average of each key.</p> <h3 id="run-shell-command-and-capture-output"><a class="header" href="#run-shell-command-and-capture-output">Run shell command and capture output</a></h3> <pre><code class="language-bash">cat /proc/1/status | awk ' /^Pid/ { - "ps --no-header -o user " $2 | getline user; + "ps --no-header -o user " $2 | getline user; print user }' </code></pre> @@ -1914,7 +1931,7 @@ thread name <name> </code></pre> <h2 id="configuration"><a class="header" href="#configuration">Configuration</a></h2> <pre><code class="language-markdown"> set disassembly-flavor <intel | att> - Set the disassembly style "flavor". + Set the disassembly style "flavor". set pagination <on | off> Turn on/off gdb's pagination. @@ -2187,7 +2204,7 @@ The wrapper will be executed before the debugee.</p> > rasm2 -a x86 'mov eax, 0xdeadbeef' b8efbeadde - > rasm2 -a x86 -d "b8efbeadde" + > rasm2 -a x86 -d "b8efbeadde" mov eax, 0xdeadbeef </code></pre> <div style="break-before: page; page-break-before: always;"></div><h1 id="qemu1"><a class="header" href="#qemu1">qemu(1)</a></h1> @@ -2379,10 +2396,10 @@ qemu-system-x86_64 -monitor stdio -incoming tcp:0.0.0.0:12345 qemu-system-x86_64 -monitor stdio -cdrom <iso> # Save VM state to file. -(qemu) migrate "exec:gzip -c > vm.gz" +(qemu) migrate "exec:gzip -c > vm.gz" # Load VM from file. -qemu-system-x86_64 -monitor stdio -incoming "exec: gzip -d -c vm.gz" +qemu-system-x86_64 -monitor stdio -incoming "exec: gzip -d -c vm.gz" </code></pre> <blockquote> <p>The migration source machine and the migration target machine should be @@ -2394,7 +2411,7 @@ launched with the <strong>same</strong> parameters.</p> -cpu host \ -enable-kvm \ -kernel <dir>/arch/x86/boot/bzImage \ - -append "earlyprintk=ttyS0 console=ttyS0 nokaslr init=/init debug" \ + -append "earlyprintk=ttyS0 console=ttyS0 nokaslr init=/init debug" \ -initrd <dir>/initramfs.cpio.gz \ ... </code></pre> @@ -2410,7 +2427,7 @@ trace: test clean: $(RM) test test-bin test.o </code></pre> -<pre><code class="language-x86asm">.section .text, "ax" +<pre><code class="language-x86asm">.section .text, "ax" .global _start _start: @@ -2474,7 +2491,7 @@ dependencies.</p> package and sort by size.</p> <pre><code class="language-text">pacman -Qetq | xargs pacman -Qi | awk '/Name/ { name=$3 } - /Installed Size/ { printf "%8.2f%s %s\n", $4, $5, name }' | + /Installed Size/ { printf "%8.2f%s %s\n", $4, $5, name }' | sort -h </code></pre> <p>Install package into different <code>root</code> directory but keep using the default @@ -2505,10 +2522,10 @@ digraph { // Add multiple edges at once. stage2 -> { stage3_1, stage3_2 } // Add edge with custom attributes. - stage3_2 -> stage4 [label="some text"] + stage3_2 -> stage4 [label="some text"] // Set custom attributes for specific node. - stage4 [color=green,fillcolor=lightgray,style="filled,dashed",label="s4"] + stage4 [color=green,fillcolor=lightgray,style="filled,dashed",label="s4"] // Create a subgraph. This can be used to group nodes/edges or as scope for // global node/edge attributes. @@ -2537,14 +2554,14 @@ digraph { <p>Following snippet allows to select a window which is then captured.</p> <pre><code class="language-bash">#!/bin/bash -echo "Click on window to record .." +echo "Click on window to record .." # Extract window size and x,y offset. video_args=$(xwininfo \ | awk '/Absolute upper-left X:/ { xoff = $4 } /Absolute upper-left Y:/ { yoff=$4 } /Width:/ { if ($2 % 2 == 1) { width=$2-1; } else { width=$2; } } /Height:/ { if ($2 % 2 == 1) { height=$2-1; } else { height=$2; } } - END { printf "-video_size %dx%d -i :0.0+%d,%d", width, height, xoff, yoff }') + END { printf "-video_size %dx%d -i :0.0+%d,%d", width, height, xoff, yoff }') ffmpeg -framerate 25 -f x11grab $video_args -pix_fmt yuv420p $@ output.mp4 </code></pre> @@ -2600,6 +2617,8 @@ c,21' | sort -k2 -n -t, -i edit file in place -i.bk edit file in place and create backup file (with .bk suffix, can be specified differently) + --follow-symlinks + follow symlinks when editing in place -e SCRIPT add SCRIPT to commands to be executed (can be specified multiple times) -f FILE add content of FILE to command to be executed @@ -2650,6 +2669,12 @@ echo -e 'aa\nbb' | sed '2aABC' echo -e 'aa\nbb' | sed '2cABC' # aa # ABC + +# Insert before pattern match. +echo -e 'aa\nbb' | sed '/bb/i 123' +# aa +# 123 +# bb </code></pre> <h3 id="substitute-lines"><a class="header" href="#substitute-lines">Substitute lines</a></h3> <pre><code class="language-sh"># Substitute by regex. @@ -2662,6 +2687,20 @@ echo -e 'aafooaa\ncc' | sed 's/foo/MOOSE/' # BAR # bar </code></pre> +<h3 id="edit-inplace-through-symlink"><a class="header" href="#edit-inplace-through-symlink">Edit inplace through symlink</a></h3> +<pre><code class="language-sh">touch file +ln -s file link +ls -l link +# lrwxrwxrwx 1 johannst johannst 4 Feb 7 23:02 link -> file + +sed -i --follow-symlinks '1iabc' link +ls -l link +# lrwxrwxrwx 1 johannst johannst 4 Feb 7 23:02 link -> file + +sed -i '1iabc' link +ls -l link +# -rw-r--r-- 1 johannst johannst 0 Feb 7 23:02 link +</code></pre> <div style="break-before: page; page-break-before: always;"></div><h1 id="gnuplot-1"><a class="header" href="#gnuplot-1">gnuplot (1)</a></h1> <pre><code># Launch interactive shell. gnuplot @@ -2671,30 +2710,30 @@ gnuplot [opt] opt: -p ................ persist plot window -c <file> ......... run script file - -e "<cmd1>; .." ... run cmd(s) + -e "<cmd1>; .." ... run cmd(s) </code></pre> <h2 id="frequently-used-configuration"><a class="header" href="#frequently-used-configuration">Frequently used configuration</a></h2> <pre><code class="language-sh"># Plot title. -set title "the plot" +set title "the plot" # Labels. -set xlabel "abc" -set ylabel "def" +set xlabel "abc" +set ylabel "def" # Output format, 'help set term' for all output formats. set term svg # Output file. -set output "out.svg" +set output "out.svg" # Make axis logarithmic to given base. set logscale x 2 # Change separator, default is whitespace. -set datafile separator "," +set datafile separator "," </code></pre> <h2 id="plot"><a class="header" href="#plot">Plot</a></h2> <pre><code class="language-sh"># With specific style (eg lines, linespoint, boxes, steps, impulses, ..). -plot "<data_file>" with <plot_style> +plot "<data_file>" with <plot_style> > cat data.txt 1 1 3 @@ -2703,30 +2742,30 @@ plot "<data_file>" with <plot_style> 4 2 2 # Plot specific column. -plot "data.txt" using 1:2, "data.txt" using 1:3 -# Equivalent using the special file "", which re-uses the previous input file. -plot "data.txt" using 1:2, "" using 1:3 +plot "data.txt" using 1:2, "data.txt" using 1:3 +# Equivalent using the special file "", which re-uses the previous input file. +plot "data.txt" using 1:2, "" using 1:3 # Plot piped data. -plot "< head -n2 data.txt" +plot "< head -n2 data.txt" # Plot with alternate title. -plot "data.txt" title "moose" +plot "data.txt" title "moose" </code></pre> <h2 id="example-multiple-data-sets-in-on-plot"><a class="header" href="#example-multiple-data-sets-in-on-plot">Example: multiple data sets in on plot</a></h2> <pre><code class="language-sh"># file: mem_lat.plot -set title "memory latency (different strides)" -set xlabel "array in KB" -set ylabel "cycles / access" +set title "memory latency (different strides)" +set xlabel "array in KB" +set ylabel "cycles / access" set logscale x 2 -plot "stride_32.txt" title "32" with linespoints, \ - "stride_64.txt" title "64" with linespoints, \ - "stride_128.txt" title "128" with linespoints, \ - "stride_256.txt" title "256" with linespoints, \ - "stride_512.txt" title "512" with linespoints +plot "stride_32.txt" title "32" with linespoints, \ + "stride_64.txt" title "64" with linespoints, \ + "stride_128.txt" title "128" with linespoints, \ + "stride_256.txt" title "256" with linespoints, \ + "stride_512.txt" title "512" with linespoints </code></pre> <p>On Linux x86_64, <a href="tools/gnuplot/mem_lat.c"><code>mem_lat.c</code></a> provides an example which can be run as follows.</p> @@ -3077,7 +3116,7 @@ databases for the different intel uarchs.</p> corresponding uarch, just grab the family model from the procfs.</p> <pre><code class="language-sh"> cat /proc/cpuinfo | awk '/^vendor_id/ { V=$3 } /^cpu family/ { F=$4 } - /^model\s*:/ { printf "%s-%d-%x\n",V,F,$3 }' + /^model\s*:/ { printf "%s-%d-%x\n",V,F,$3 }' </code></pre> <blockquote> <p>The table in <a href="https://github.com/intel/perfmon/tree/main#performance-monitoring-events">performance monitoring events</a> describes how @@ -3111,7 +3150,7 @@ perf script --per-event-dump </code></pre> <h2 id="examples-10"><a class="header" href="#examples-10">Examples</a></h2> <h3 id="estimate-max-instructions-per-cycle"><a class="header" href="#estimate-max-instructions-per-cycle">Estimate max instructions per cycle</a></h3> -<pre><code class="language-c">#define NOP4 "nop\nnop\nnop\nnop\n" +<pre><code class="language-c">#define NOP4 "nop\nnop\nnop\nnop\n" #define NOP32 NOP4 NOP4 NOP4 NOP4 NOP4 NOP4 NOP4 NOP4 #define NOP256 NOP32 NOP32 NOP32 NOP32 NOP32 NOP32 NOP32 NOP32 #define NOP2048 NOP256 NOP256 NOP256 NOP256 NOP256 NOP256 NOP256 NOP256 @@ -3370,7 +3409,7 @@ disassemble with <code>objdump</code>.</p> <p>To re-create that case, we just assemble and link some ELF file and then create a raw binary of the text section with <code>objcopy</code>.</p> <pre><code class="language-x86asm"># file: test.s -.section .text, "ax" +.section .text, "ax" .global _start _start: @@ -3582,7 +3621,7 @@ int* P = reinterpret_cast<int*>(C); // Cast is ok, not yet UB. </li> <li> <p>On <code>gcc</code> strict aliasing is enabled starting with <code>-O2</code>.</p> -<pre><code class="language-bash">for i in {0..3} g s; do echo "-O$i $(g++ -Q --help=optimizers -O$i | grep fstrict-aliasing)"; done +<pre><code class="language-bash">for i in {0..3} g s; do echo "-O$i $(g++ -Q --help=optimizers -O$i | grep fstrict-aliasing)"; done -O0 -fstrict-aliasing [disabled] -O1 -fstrict-aliasing [disabled] -O2 -fstrict-aliasing [enabled] @@ -3635,13 +3674,13 @@ to violate self defined contract, see <a href="https://godbolt.org/z/e8x1af3Mh"> // Base case with one parameter. template<int P> void show_int() { - printf("%d\n", P); + printf("%d\n", P); } // General case with at least two parameters, to disambiguate from base case. template<int P0, int P1, int... Params> void show_int() { - printf("%d, ", P0); + printf("%d, ", P0); show_int<P1, Params...>(); } @@ -3656,13 +3695,13 @@ void show(const T& t) { // General case with at least two parameters, to disambiguate from base case. template<typename T0, typename T1, typename... Types> void show(const T0& t0, const T1& t1, const Types&... types) { - std::cout << t0 << ", "; + std::cout << t0 << ", "; show(t1, types...); } int main() { show_int<1, 2, 3, 4, 5>(); - show(1, 1.0, "foo", 'a'); + show(1, 1.0, "foo", 'a'); } </code></pre> <h2 id="forwarding-reference-fwd-ref"><a class="header" href="#forwarding-reference-fwd-ref">Forwarding reference (<a href="https://en.cppreference.com/w/cpp/language/reference#Forwarding_references">fwd ref</a>)</a></h2> @@ -3712,21 +3751,21 @@ void fwd_wrapper(T&& param) { // forwarding reference int main() { { - std::puts("==> wrapper rvalue reference"); + std::puts("==> wrapper rvalue reference"); wrapper(M{}); // calls use(M&). - std::puts("==> wrapper lvalue reference"); + std::puts("==> wrapper lvalue reference"); struct M m; wrapper(m); // calls use(M&). } { - std::puts("==> fwd_wrapper rvalue reference"); + std::puts("==> fwd_wrapper rvalue reference"); fwd_wrapper(M{}); // calls use(M&&). - std::puts("==> fwd_wrapper lvalue reference"); + std::puts("==> fwd_wrapper lvalue reference"); struct M m; fwd_wrapper(m); // calls use(M&). @@ -3752,8 +3791,8 @@ struct any_of<T, U0, U...> : any_of<T, U...> {}; template<typename T, typename... U> constexpr bool any_of_v = any_of<T, U...>::value; -static_assert(any_of_v<int, char, bool, int>, ""); -static_assert(!any_of_v<int, char, bool, float>, ""); +static_assert(any_of_v<int, char, bool, int>, ""); +static_assert(!any_of_v<int, char, bool, float>, ""); </code></pre> <h2 id="example-sfinae-enable_if"><a class="header" href="#example-sfinae-enable_if">Example: <a href="https://en.cppreference.com/w/cpp/language/sfinae">SFINAE</a> (<a href="https://en.cppreference.com/w/cpp/types/enable_if">enable_if</a>)</a></h2> <p>Provide a single entry point <code>Invoke</code> to call some <code>Operations</code>. @@ -3799,16 +3838,16 @@ namespace impl { template<typename Ctx, template<typename> class Op, typename... P, enable_if_bool<has_dst<Op<Ctx>>> = true> void Invoke(const Ctx& C, P... params) { - std::cout << "Invoke " << Op<Ctx>::Name << '\n'; + std::cout << "Invoke " << Op<Ctx>::Name << '\n'; typename Op<Ctx>::Return R = impl::Invoke<Ctx, Op>(C, params...); - std::cout << "returned -> " << R << '\n'; + std::cout << "returned -> " << R << '\n'; } // Invoke an OPERATION which has *NOT* a DESTINATION with arbitrary number of arguments. template<typename Ctx, template<typename> class Op, typename... P, disable_if_bool<has_dst<Op<Ctx>>> = true> void Invoke(const Ctx& C, P... params) { - std::cout << "Invoke " << Op<Ctx>::Name << " without destination." << '\n'; + std::cout << "Invoke " << Op<Ctx>::Name << " without destination." << '\n'; impl::Invoke<Ctx, Op>(C, params...); } @@ -3816,7 +3855,7 @@ void Invoke(const Ctx& C, P... params) { struct Ctx { void out(const char* s, unsigned v) const { - printf("%s%x\n", s, v); + printf("%s%x\n", s, v); } }; @@ -3826,7 +3865,7 @@ template<typename Ctx> struct OpA { using HasCtx = std::false_type; using Return = int; - static constexpr const char* const Name = "OpA"; + static constexpr const char* const Name = "OpA"; constexpr Return operator()(int a, int b) const { return a + b; @@ -3837,10 +3876,10 @@ template<typename Ctx> struct OpB { using HasCtx = std::true_type; using Return = void; - static constexpr const char* const Name = "OpB"; + static constexpr const char* const Name = "OpB"; Return operator()(const Ctx& C, unsigned a) const { - C.out("a = ", a); + C.out("a = ", a); } }; @@ -3906,7 +3945,7 @@ struct registry { const auto it = m_fns.find(nm); if (it == m_fns.end()) { static_assert(std::is_default_constructible_v<RET>, - "RET must be default constructible"); + "RET must be default constructible"); return {}; } return std::invoke(it->second, p...); @@ -3917,7 +3956,7 @@ struct registry { static bool regfn_##REGISTRY##NAME() { \ const bool r = REGISTRY::get().add(#NAME, NAME); \ if (!r) { \ - std::puts("Failed to register test " #NAME ", same name already registered!"); \ + std::puts("Failed to register test " #NAME ", same name already registered!"); \ std::abort(); \ } \ return r; \ @@ -3933,10 +3972,10 @@ struct registry { using REG1 = registry<void>; TEST(REG1, test1) { - std::puts("REG1::test1"); + std::puts("REG1::test1"); } TEST(REG1, test2) { - std::puts("REG1::test2"); + std::puts("REG1::test2"); } // -- Usage 2 with convenience macro wrapper. @@ -3945,18 +3984,18 @@ using REG2 = registry<void, bool>; #define TEST2(NAME, ...) TEST(REG2, NAME, ##__VA_ARGS__) TEST2(test1, bool val) { - printf("REG2::test1 val %d\n", val); + printf("REG2::test1 val %d\n", val); } int main() { const auto& R1 = REG1::get(); R1.dump(); - R1.invoke("test1"); - R1.invoke("test2"); + R1.invoke("test1"); + R1.invoke("test2"); const auto& R2 = REG2::get(); R2.dump(); - R2.invoke("test1", true); + R2.invoke("test1", true); return 0; } @@ -4013,7 +4052,7 @@ struct Entry { }; int main() { - static_assert(is_entry_v<Entry<bool>>, ""); + static_assert(is_entry_v<Entry<bool>>, ""); } </code></pre> <p>The main mechanic can be explained with the following reduced example. If one @@ -4037,7 +4076,7 @@ struct A { struct B {}; -static_assert(is_valid<A>::value, "is true"); +static_assert(is_valid<A>::value, "is true"); // * Compare template arg list with primary template, we only supplied one // arg, the second one will be defaulted as // is_valid<A, void> @@ -4051,7 +4090,7 @@ static_assert(is_valid<A>::value, "is true"); // * Specialization (2) matches <A, void> // * Pick the most specialized version -> (2) -static_assert(!is_valid<B>::value, "is false"); +static_assert(!is_valid<B>::value, "is false"); // * Compare template arg list with primary template, we only supplied one // arg, the second one will be defaulted as // is_valid<A, void> @@ -4102,7 +4141,7 @@ struct pair<int, int> { }; int main() { - static_assert(pair<int>::kind == kIntBool, ""); + static_assert(pair<int>::kind == kIntBool, ""); // * Compare template arg list with primary template, we only supplied one // arg, the second one will be defaulted as // pair<int, bool> @@ -4114,7 +4153,7 @@ int main() { // * (4) <int, bool> pattern does not match // * Pick the most specialized version -> (3) - static_assert(pair<char, char>::kind == kTT, ""); + static_assert(pair<char, char>::kind == kTT, ""); // * Compare template arg list against available specializations, this will // try to match the pattern <char, char> against the patterns defined in the // partial specializations. @@ -4123,7 +4162,7 @@ int main() { // * (4) <char, char> pattern does not match // * Pick the most specialized version -> (2) - static_assert(pair<int, int>::kind == kIntInt, ""); + static_assert(pair<int, int>::kind == kIntInt, ""); // * Compare template arg list against available specializations, this will // try to match the pattern <int, int> against the patterns defined in the // partial specializations. @@ -4132,7 +4171,7 @@ int main() { // * (4) <int, int> pattern does not match // * Pick the most specialized version -> (3) - static_assert(pair<char, short>::kind == kPrimary, ""); + static_assert(pair<char, short>::kind == kPrimary, ""); // * Compare template arg list against available specializations, this will // try to match the pattern <char, short> against the patterns defined in the // partial specializations. @@ -4153,25 +4192,25 @@ struct S {}; struct M { M() { - std::puts("M()"); + std::puts("M()"); } M(const M&) { - std::puts("M(M&)"); + std::puts("M(M&)"); } M(M&&) { - std::puts("M(M&&)"); + std::puts("M(M&&)"); } M& operator=(const M&) = delete; M& operator=(M&&) = delete; M(S&, int) { - std::puts("M(S&)"); + std::puts("M(S&)"); } M(S&&, int) { - std::puts("M(S&&)"); + std::puts("M(S&&)"); } ~M() { - std::puts("~M()"); + std::puts("~M()"); } }; @@ -4219,11 +4258,11 @@ struct option { }; int main() { - std::puts("==> case 1"); + std::puts("==> case 1"); // invokes M(S&&, int) option<M> opt1(S{}, 123); - std::puts("==> case 2"); + std::puts("==> case 2"); // invokes M() + M(M&&) option<M> x /* option(M&&) + M(M&&) */ = M{} /* M() */; } @@ -4295,7 +4334,7 @@ accordingly to reduce number of jump instructions. See on <a href="https://godbolt.org/z/MbTHAP">compiler explorer</a>.</p> <p>The semantics of this hint are as follows, the compiler prioritises <code>expr == cond</code>. So <code>__builtin_expect(expr, 0)</code> means that we expect the <code>expr</code> to be <code>0</code> most of the time.</p> -<pre><code class="language-bash">echo " +<pre><code class="language-bash">echo " extern void foo(); extern void bar(); void run0(int x) { @@ -4306,7 +4345,7 @@ void run1(int x) { if (__builtin_expect(x,1)) { foo(); } else { bar(); } } -" | gcc -O2 -S -masm=intel -o /dev/stdout -xc - +" | gcc -O2 -S -masm=intel -o /dev/stdout -xc - </code></pre> <p>Will generate something similar to the following.</p> <ul> @@ -4332,7 +4371,7 @@ run1: </code></pre> <h2 id="abi-linux"><a class="header" href="#abi-linux">ABI (Linux)</a></h2> <ul> -<li>C ABI - <a href="https://www.uclibc.org/docs/psABI-x86_64.pdf">SystemV ABI</a></li> +<li>C ABI (x86_64) - <a href="https://gitlab.com/x86-psABIs/x86-64-ABI">SystemV ABI</a></li> <li>C++ ABI - <a href="https://itanium-cxx-abi.github.io/cxx-abi">C++ Itanium ABI</a></li> </ul> <div style="break-before: page; page-break-before: always;"></div><h1 id="cmake1"><a class="header" href="#cmake1">cmake(1)</a></h1> @@ -4362,7 +4401,7 @@ target_compile_definitions(liba INTERFACE DEF_INTERFACE) add_executable(main main.cc) target_link_libraries(main liba) </code></pre> -<pre><code class="language-sh">> touch liba.cc; echo "int main() {}" > main.cc +<pre><code class="language-sh">> touch liba.cc; echo "int main() {}" > main.cc > cmake -B build -S . -G Ninja > ninja -C build -j1 --verbose [1/4] /usr/bin/c++ -DDEF_PRIVATE -DDEF_PUBLIC [..] .../liba.cc @@ -4409,12 +4448,12 @@ the recipe, make provides a set of automatic variables to work with:</p> all: foobar blabla foo% bla%: aaa bbb bbb - @echo "@ = $@" - @echo "< = $<" - @echo "^ = $^" - @echo "+ = $+" - @echo "* = $*" - @echo "----" + @echo "@ = $@" + @echo "< = $<" + @echo "^ = $^" + @echo "+ = $+" + @echo "* = $*" + @echo "----" aaa: bbb: @@ -4503,10 +4542,10 @@ Therefore the following is a code smell:</p> <pre><code class="language-c">// at startup LD_LIBRARY_PATH=/moose // Assume /foo/libbar.so -setenv("LD_LIBRARY_PATH", "/foo", true /* overwrite */); +setenv("LD_LIBRARY_PATH", "/foo", true /* overwrite */); // Will look in /moose and NOT in /foo. -dlopen("libbar.so", RTLD_LAZY); +dlopen("libbar.so", RTLD_LAZY); </code></pre> <h2 id="ld_preload-initialization-order-and-link-map"><a class="header" href="#ld_preload-initialization-order-and-link-map">LD_PRELOAD: Initialization Order and Link Map</a></h2> <p>Libraries specified in <code>LD_PRELOAD</code> are loaded from <code>left-to-right</code> but @@ -4630,10 +4669,10 @@ Symbol table '.dynsym' contains 342 entries: static linking against the library. The following dump shows that the <code>tmp</code> program linked against <code>lpthread</code> will depend on the symbol version <code>GLIBC_2.3.2</code>, which is the default version.</p> -<pre><code class="language-bash">> echo "#include <pthread.h> +<pre><code class="language-bash">> echo "#include <pthread.h> int main() { return pthread_cond_wait(0,0); - }" | gcc -o tmp -xc - -lpthread; + }" | gcc -o tmp -xc - -lpthread; readelf -W --dyn-syms tmp | grep pthread_cond_wait; Symbol table '.dynsym' contains 7 entries: @@ -4705,23 +4744,23 @@ symbol multiple times but in different versions.</p> // ..@ -> Is the unversioned symbol. // ..@@.. -> Is the default symbol. -__asm__(".symver func_v0,func@"); -__asm__(".symver func_v1,func@LIB_V1"); -__asm__(".symver func_v2,func@@LIB_V2"); +__asm__(".symver func_v0,func@"); +__asm__(".symver func_v1,func@LIB_V1"); +__asm__(".symver func_v2,func@@LIB_V2"); -extern "C" { - void func_v0() { puts("func_v0"); } - void func_v1() { puts("func_v1"); } - void func_v2() { puts("func_v2"); } +extern "C" { + void func_v0() { puts("func_v0"); } + void func_v1() { puts("func_v1"); } + void func_v2() { puts("func_v2"); } } -__asm__(".symver _Z11func_cpp_v1i,_Z8func_cppi@LIB_V1"); -__asm__(".symver _Z11func_cpp_v2i,_Z8func_cppi@@LIB_V2"); +__asm__(".symver _Z11func_cpp_v1i,_Z8func_cppi@LIB_V1"); +__asm__(".symver _Z11func_cpp_v2i,_Z8func_cppi@@LIB_V2"); -void func_cpp_v1(int) { puts("func_cpp_v1"); } -void func_cpp_v2(int) { puts("func_cpp_v2"); } +void func_cpp_v1(int) { puts("func_cpp_v1"); } +void func_cpp_v2(int) { puts("func_cpp_v2"); } -void func_cpp(int) { puts("func_cpp_v2"); } +void func_cpp(int) { puts("func_cpp_v2"); } </code></pre> <p>Version script for <code>libfoo</code> which defines which symbols for which versions are exported from the ELF file.</p> @@ -4729,8 +4768,8 @@ exported from the ELF file.</p> LIB_V1 { global: func; - extern "C++" { - "func_cpp(int)"; + extern "C++" { + "func_cpp(int)"; }; local: *; @@ -4739,8 +4778,8 @@ LIB_V1 { LIB_V2 { global: func; - extern "C++" { - "func_cpp(int)"; + extern "C++" { + "func_cpp(int)"; }; } LIB_V1; </code></pre> @@ -4772,7 +4811,7 @@ Symbol table '.dynsym' contains 14 entries: #include <assert.h> // Links against default symbol in the lib.so. -extern "C" void func(); +extern "C" void func(); int main() { // Call the default version. @@ -4782,10 +4821,10 @@ int main() { typedef void (*fnptr)(); // Unversioned lookup. - fnptr fn_v0 = (fnptr)dlsym(RTLD_DEFAULT, "func"); + fnptr fn_v0 = (fnptr)dlsym(RTLD_DEFAULT, "func"); // Version lookup. - fnptr fn_v1 = (fnptr)dlvsym(RTLD_DEFAULT, "func", "LIB_V1"); - fnptr fn_v2 = (fnptr)dlvsym(RTLD_DEFAULT, "func", "LIB_V2"); + fnptr fn_v1 = (fnptr)dlvsym(RTLD_DEFAULT, "func", "LIB_V1"); + fnptr fn_v2 = (fnptr)dlvsym(RTLD_DEFAULT, "func", "LIB_V2"); assert(fn_v0 != 0); assert(fn_v1 != 0); @@ -4821,26 +4860,26 @@ func_v2 def log(f: Callable[[int], None]) -> Callable[[int], None]: def inner(x: int): - print(f"log::inner f={f.__name__} x={x}") + print(f"log::inner f={f.__name__} x={x}") f(x) return inner @log def some_fn(x: int): - print(f"some_fn x={x}") + print(f"some_fn x={x}") def log_tag(tag: str) -> Callable[[Callable[[int], None]], Callable[[int], None]]: def decorator(f: Callable[[int], None]) -> Callable[[int], None]: def inner(x: int): - print(f"log_tag::inner f={f.__name__} tag={tag} x={x}") + print(f"log_tag::inner f={f.__name__} tag={tag} x={x}") f(x) return inner return decorator -@log_tag("some_tag") +@log_tag("some_tag") def some_fn2(x: int): - print(f"some_fn2 x={x}") + print(f"some_fn2 x={x}") </code></pre> <h2 id="walrus-operator-run"><a class="header" href="#walrus-operator-run">Walrus operator [<a href="https://www.online-python.com/9T12PvmKVy">run</a>]</a></h2> <p>Walrus operator <code>:=</code> added since <strong>python 3.8</strong>.</p> @@ -4852,20 +4891,20 @@ def foo(ret: Optional[int]) -> Optional[int]: return ret if r := foo(None): - print(f"foo(None) -> {r}") + print(f"foo(None) -> {r}") if r := foo(1337): - print(f"foo(1337) -> {r}") + print(f"foo(1337) -> {r}") # Example 2: while let statements toks = iter(['a', 'b', 'c']) while tok := next(toks, None): - print(f"{tok}") + print(f"{tok}") # Example 3: list comprehension -print([tok for t in [" a", " ", " b "] if (tok := t.strip())]) +print([tok for t in [" a", " ", " b "] if (tok := t.strip())]) </code></pre> <h2 id="unittest-run"><a class="header" href="#unittest-run"><a href="https://docs.python.org/3/library/unittest.html">Unittest</a> [<a href="https://www.online-python.com/2fit4UcbzI">run</a>]</a></h2> <p>Run unittests directly from the command line as <br /> @@ -4893,19 +4932,19 @@ class MyTest(unittest.TestCase): <pre><code class="language-python"># file: test.py def sum(a: int, b: int) -> int: - """Sum a and b. + """Sum a and b. >>> sum(1, 2) 3 >>> sum(10, 20) 30 - """ + """ return a + b </code></pre> <h2 id="timeit"><a class="header" href="#timeit"><a href="https://docs.python.org/3/library/timeit.html">timeit</a></a></h2> <p>Micro benchmarking.</p> -<pre><code class="language-bash">python -m timeit '[x.strip() for x in ["a ", " b"]]' +<pre><code class="language-bash">python -m timeit '[x.strip() for x in ["a ", " b"]]' </code></pre> <div style="break-before: page; page-break-before: always;"></div><h1 id="gcov1"><a class="header" href="#gcov1">gcov(1)</a></h1> <p>Generate code coverage reports in text format.</p> @@ -4934,9 +4973,9 @@ generated for a single file for example such as</p> void tell_me(int desc) { if (desc & 1) { - std::puts("this"); + std::puts("this"); } else { - std::puts("that"); + std::puts("that"); } } @@ -4982,9 +5021,9 @@ clean: -: 4: 2: 5:void tell_me(int desc) { 2: 6: if (desc & 1) { - 2: 7: std::puts("this"); + 2: 7: std::puts("this"); -: 8: } else { - #####: 9: std::puts("that"); + #####: 9: std::puts("that"); -: 10: } 2: 11:} -: 12: @@ -5007,8 +5046,8 @@ workload.</p> #define NOINLINE __attribute__((noinline)) -NOINLINE void foo() { puts("foo()"); } -NOINLINE void bar() { puts("bar()"); } +NOINLINE void foo() { puts("foo()"); } +NOINLINE void bar() { puts("bar()"); } int main(int argc, char *argv[]) { if (argc == 2) { @@ -5049,7 +5088,7 @@ clang -o test test.cc -O3 -fprofile-instr-generate # Collect profiling data from multiple runs. for i in {0..10}; do - LLVM_PROFILE_FILE="prof.clang/%p.profraw" ./test $(seq 0 $i) + LLVM_PROFILE_FILE="prof.clang/%p.profraw" ./test $(seq 0 $i) done # Merge raw profiling data into single profile data. @@ -5186,7 +5225,7 @@ Description=Test logger [Service] Type=oneshot -ExecStart=logger "Hello from test unit"' > ~/.config/systemd/user/test.service +ExecStart=logger "Hello from test unit"' > ~/.config/systemd/user/test.service # Run unit systemctl --user start test @@ -5238,7 +5277,7 @@ In a typical bash/zsh this can be done as</p> /proc/sys/kernel/core_uses_pid - 1 => Append ".<pid>" suffic to the coredump file name + 1 => Append ".<pid>" suffic to the coredump file name (pid of the dumping process). 0 => Do not append the suffix. </code></pre> @@ -5393,7 +5432,7 @@ mkswap /swapfile swapon /swapfile # Persistent setup of swap file. -echo "/swapfile none swap sw 0 0" | sudo tee -a /etc/fstab +echo "/swapfile none swap sw 0 0" | sudo tee -a /etc/fstab # Disable swap file (until next reboot). swapoff /swapfile @@ -5456,7 +5495,7 @@ file <code>/proc/bus/input/devices</code> in the proc filesystem can be consulte <p>This yields entries as follows and shows which <code>Handlers</code> are assigned to which <code>Name</code>.</p> <pre><code>I: Bus=0018 Vendor=04f3 Product=0033 Version=0000 -N: Name="Elan Touchpad" +N: Name="Elan Touchpad" ... H: Handlers=event15 mouse0 ... @@ -5481,9 +5520,9 @@ struct input_event { const char* type(unsigned short t) { static char buf[32]; - const char* fmt = "0x%x"; + const char* fmt = "0x%x"; switch (t) { -#define FMT(TYPE) case TYPE: fmt = #TYPE"(0x%x)"; break +#define FMT(TYPE) case TYPE: fmt = #TYPE"(0x%x)"; break FMT(EV_SYN); FMT(EV_KEY); FMT(EV_REL); @@ -5496,9 +5535,9 @@ const char* type(unsigned short t) { const char* code(unsigned short c) { static char buf[32]; - const char* fmt = "0x%x"; + const char* fmt = "0x%x"; switch (c) { -#define FMT(CODE) case CODE: fmt = #CODE"(0x%x)"; break +#define FMT(CODE) case CODE: fmt = #CODE"(0x%x)"; break FMT(BTN_LEFT); FMT(BTN_RIGHT); FMT(BTN_MIDDLE); @@ -5514,7 +5553,7 @@ const char* timefmt(const struct timeval* t) { assert(t); struct tm* lt = localtime(&t->tv_sec); // Returns pointer to static tm object. static char buf[64]; - strftime(buf, sizeof(buf), "%H:%M:%S", lt); + strftime(buf, sizeof(buf), "%H:%M:%S", lt); return buf; } @@ -5528,7 +5567,7 @@ int main(int argc, char* argv[]) { while (1) { int ret = read(fd, &inp, sizeof(inp)); assert(ret == sizeof(inp)); - printf("time: %s type: %s code: %s value: 0x%x\n", + printf("time: %s type: %s code: %s value: 0x%x\n", timefmt(&inp.time), type(inp.type), code(inp.code), inp.value); } } @@ -5559,17 +5598,17 @@ drwxrwxr-x+ 2 root root 4 11. Jun 14:26 foo/ getfacl /tank/foo </code></pre> <h2 id="modify-acl-entries"><a class="header" href="#modify-acl-entries">Modify acl entries</a></h2> -<pre><code class="language-bash"># Add acl entry for user "user123". -setfacl -m "u:user123:rwx" /tank/foo +<pre><code class="language-bash"># Add acl entry for user "user123". +setfacl -m "u:user123:rwx" /tank/foo -# Remove entry for user "user123". -setfacl -x "u:user123" /tank/foo +# Remove entry for user "user123". +setfacl -x "u:user123" /tank/foo -# Add acl entry for group "group456". -setfacl -m "g:group456:rx" /tank/foo +# Add acl entry for group "group456". +setfacl -m "g:group456:rx" /tank/foo # Add acl entry for others. -setfacl -m "o:rx" /tank/foo +setfacl -m "o:rx" /tank/foo # Remove extended acl entries. setfacl -b /tank/foo @@ -5578,7 +5617,7 @@ setfacl -b /tank/foo <p>The <code>mask</code> defines the maximum access rights that can be given to <strong>users</strong> and <strong>groups</strong>.</p> <pre><code class="language-bash"># Update the mask. -setfacl -m "m:rx" /tank/foo +setfacl -m "m:rx" /tank/foo # List acl entries. getfacl /tank/foo @@ -5867,7 +5906,7 @@ tcp.dstport == 80 Filter for tcp destinatio port. tcp/udp/ssh/wg/... Filter for protocol. -"and/or/not/!" and "()" can be used to build filter expressions. +"and/or/not/!" and "()" can be used to build filter expressions. </code></pre> <blockquote> <p>Use <code>tshak -G</code> to list all fields that can be used in display filters.</p> @@ -5904,7 +5943,7 @@ firewall-cmd --add-service <SERVICE> # Add a specific port. firewall-cmd --add-port 8000/tcp # Add a rich rule (eg port forwarding, dnat). -firewall-cmd --add-rich-rule 'rule family="ipv4" forward-port port="80" protocol="tcp" to-port="8080"' +firewall-cmd --add-rich-rule 'rule family="ipv4" forward-port port="80" protocol="tcp" to-port="8080"' </code></pre> <h2 id="remove-entries"><a class="header" href="#remove-entries">Remove entries</a></h2> <pre><code class="language-sh"># Remove service. @@ -5912,7 +5951,7 @@ firewall-cmd --remove-service <SERVICE> # Remove port. firewall-cmd --remove-port 8000/tcp # Remove rich rule. -firewall-cmd --remove-rich-rule 'rule family="ipv4" forward-port port="80" protocol="tcp" to-port="8080"' +firewall-cmd --remove-rich-rule 'rule family="ipv4" forward-port port="80" protocol="tcp" to-port="8080"' </code></pre> <h2 id="references-6"><a class="header" href="#references-6">References</a></h2> <ul> @@ -6047,11 +6086,11 @@ nc localhost 8200 padding-left: 1em; } </style> -<div class="grid-2col"> - <div class="col1"> +<div class="grid-2col"> + <div class="col1"> <p>Some text in the first column.</p> </div> - <div class="col2"> + <div class="col2"> <p>Some text in the second column.</p> </div> </div> @@ -6063,9 +6102,9 @@ nc localhost 8200 display: grid; grid-template-columns: 1fr 2fr; grid-template-areas: - "h h" - "s m" - "f f"; + "h h" + "s m" + "f f"; gap: 1em; } .gh { @@ -6094,21 +6133,21 @@ p { margin: 1em; } </style> -<div class="page-grid"> - <div class="gh"> - <ul class="nav-items"> - <li class="nav-item"><a href="">aa</a></li> - <li class="nav-item"><a href="">bb</a></li> - <li class="nav-item"><a href="">cc</a></li> +<div class="page-grid"> + <div class="gh"> + <ul class="nav-items"> + <li class="nav-item"><a href="">aa</a></li> + <li class="nav-item"><a href="">bb</a></li> + <li class="nav-item"><a href="">cc</a></li> </ul> </div> - <div class="gs"> + <div class="gs"> <p>Some text in the second column.</p> </div> - <div class="gm"> + <div class="gm"> <p>Some text in the second column.</p> </div> - <div class="gf"> + <div class="gf"> <p>Some text in the second column.</p> </div> </div> @@ -6118,58 +6157,58 @@ p { <p><a href="web/src/tabs.html">Rendered html</a></p> <pre><code class="language-html"><script> const showTab = (E, T) => { - const TABS = Array.from(document.getElementsByClassName("content")); + const TABS = Array.from(document.getElementsByClassName("content")); TABS.forEach(T => { - T.style.display = "none"; + T.style.display = "none"; }); - document.getElementById(T).style.display = "block"; + document.getElementById(T).style.display = "block"; }; window.onload = () => { - document.getElementById("bTab1").onclick = (E) => { - showTab(E, "tTab1"); + document.getElementById("bTab1").onclick = (E) => { + showTab(E, "tTab1"); }; - document.getElementById("bTab2").onclick = (E) => { - showTab(E, "tTab2"); + document.getElementById("bTab2").onclick = (E) => { + showTab(E, "tTab2"); }; } </script> -<button type="button" id="bTab1">Tab1</button> -<button type="button" id="bTab2">Tab2</button> +<button type="button" id="bTab1">Tab1</button> +<button type="button" id="bTab2">Tab2</button> -<div id="tTab1" class="content" style="display: block;"> +<div id="tTab1" class="content" style="display: block;"> <p>Some content goes here ...</p> </div> -<div id="tTab2" class="content" style="display: none;"> +<div id="tTab2" class="content" style="display: none;"> <p>... and there.</p> </div> </code></pre> <div style="break-before: page; page-break-before: always;"></div><h1 id="css"><a class="header" href="#css">css</a></h1> <h2 id="selector"><a class="header" href="#selector">selector</a></h2> <p><code>.moose</code> element with class</p> -<pre><code class="language-html"><div class = "moose"></div> // selected -<div class = "bar"></div> // NOT selected +<pre><code class="language-html"><div class = "moose"></div> // selected +<div class = "bar"></div> // NOT selected </code></pre> <p><code>.moose.bar</code> element with multiple classes</p> -<pre><code class="language-html"><div class = "moose bar"></div> // selected -<div class = "bar"></div> // NOT selected +<pre><code class="language-html"><div class = "moose bar"></div> // selected +<div class = "bar"></div> // NOT selected </code></pre> <p><code>.moose .bar</code> descendant element with classes</p> -<pre><code class="language-html"><div class = "moose"> - <div class = "bar"></div> // selected +<pre><code class="language-html"><div class = "moose"> + <div class = "bar"></div> // selected </div> -<div class = "bar"></div> // NOT selected +<div class = "bar"></div> // NOT selected </code></pre> <p><code>p</code> specific element</p> <pre><code class="language-html"><p></p> // selected <div></div> // NOT selected </code></pre> <p><code>p.bar</code> specific element with class</p> -<pre><code class="language-html"><p class = "bar"></p> // selected -<p class = "foo"></p> // NOT selected +<pre><code class="language-html"><p class = "bar"></p> // selected +<p class = "foo"></p> // NOT selected </code></pre> <p><code>p,div</code> any element</p> <pre><code class="language-html"><p></p> // selected @@ -6187,7 +6226,7 @@ window.onload = () => { <div style="break-before: page; page-break-before: always;"></div><h1 id="chartjs"><a class="header" href="#chartjs">Chart.js</a></h1> <h2 id="minimal-example-with-external-tooltips"><a class="header" href="#minimal-example-with-external-tooltips">Minimal example with <em>external</em> tooltips</a></h2> <p><a href="web/src/chartjs-ext-tooltip.html">Rendered html</a></p> -<pre><code class="language-html"><canvas id="myChart" style="margin:5em;"></canvas> +<pre><code class="language-html"><canvas id="myChart" style="margin:5em;"></canvas> <script> const get_or_create_tooltip = (id) => { @@ -6223,12 +6262,12 @@ const render_tooltip = (context) => { // -- Format new tooltip. const link = document.createElement('a'); - link.href = "https://github.com/johannst"; - link.innerHTML = "X:" + x + " Y:" + y; + link.href = "https://github.com/johannst"; + link.innerHTML = "X:" + x + " Y:" + y; // -- Remove previous child element and add new one. const table = tooltip_elem.querySelector('table'); - table.innerHTML = ""; + table.innerHTML = ""; table.appendChild(link); // -- Get absolute X/Y position of the top left corner of the canvas. @@ -6240,9 +6279,9 @@ const render_tooltip = (context) => { tooltip_elem.style.font = tooltip.options.bodyFont.string; // -- Place the tooltip (I) left or (II) right of the data point. - if (tooltip.xAlign === "right") { + if (tooltip.xAlign === "right") { tooltip_elem.style.transform = 'translate(-100%, 0)'; // (I) - } else if (tooltip.xAlign === "left") { + } else if (tooltip.xAlign === "left") { tooltip_elem.style.transform = 'translate(0%, 0)'; // (II) } } @@ -6368,7 +6407,7 @@ mov rax, qword ptr [rbx+4*rcx] // load val at [rbx+4*rcx] into rax <pre><code class="language-x86asm">lea rax, [rip+.my_str] // load addr of .my_str into rax ... .my_str: -.asciz "Foo" +.asciz "Foo" </code></pre> <p>Load effective address:</p> <pre><code class="language-x86asm">mov rax, 2 @@ -6418,7 +6457,7 @@ mov al, 0xaa mov cx, 0x10 rep stosb </code></pre> -<h2 id="sysv-x86_64-abi"><a class="header" href="#sysv-x86_64-abi"><a href="https://www.uclibc.org/docs/psABI-x86_64.pdf">SysV x86_64 ABI</a></a></h2> +<h2 id="sysv-x86_64-abi"><a class="header" href="#sysv-x86_64-abi"><a href="https://gitlab.com/x86-psABIs/x86-64-ABI">SysV x86_64 ABI</a></a></h2> <h3 id="passing-arguments-to-functions"><a class="header" href="#passing-arguments-to-functions">Passing arguments to functions</a></h3> <ul> <li>Integer/Pointer arguments @@ -6589,7 +6628,7 @@ must must save these registers in case they are used.</p> .intel_syntax noprefix - .section .text, "ax", @progbits + .section .text, "ax", @progbits .global _start _start: mov rdi, 1 # fd @@ -6602,9 +6641,9 @@ _start: mov rax, 60 # exit(2) syscall nr syscall - .section .rdonly, "a", @progbits + .section .rdonly, "a", @progbits greeting: - .asciz "Hi ASM-World!\n" + .asciz "Hi ASM-World!\n" greeting_len: .int .-greeting </code></pre> @@ -6617,7 +6656,7 @@ Hi ASM-World! </code></pre> <h2 id="references-7"><a class="header" href="#references-7">References</a></h2> <ul> -<li><a href="https://www.uclibc.org/docs/psABI-x86_64.pdf">SystemV AMD64 ABI</a></li> +<li><a href="https://gitlab.com/x86-psABIs/x86-64-ABI">SystemV AMD64 ABI</a></li> <li><a href="https://www.amd.com/system/files/TechDocs/24592.pdf">AMD64 Vol1: Application Programming</a></li> <li><a href="https://www.amd.com/system/files/TechDocs/24593.pdf">AMD64 Vol2: System Programming</a></li> <li><a href="https://www.amd.com/system/files/TechDocs/24594.pdf">AMD64 Vol3: General-Purpose & System Instructions</a></li> @@ -6809,7 +6848,7 @@ ret .arch armv8-a - .section .text, "ax", @progbits + .section .text, "ax", @progbits .balign 4 // align code on 4byte boundary .global _start _start: @@ -6825,9 +6864,9 @@ _start: svc 0 .balign 8 // align data on 8byte boundary - .section .rodata, "a", @progbits + .section .rodata, "a", @progbits greeting: - .asciz "Hi ASM-World!\n" + .asciz "Hi ASM-World!\n" greeting_len: .int .-greeting </code></pre> @@ -7041,7 +7080,7 @@ mov fp, sp // FP points to frame record .arch armv7-a - .section .text, "ax" + .section .text, "ax" .balign 4 // Emit `arm` instructions, same as `.arm` directive. @@ -7070,9 +7109,9 @@ _do_greet: bx lr .balign 8 // align data on 8byte boundary - .section .rodata, "a" + .section .rodata, "a" greeting: - .asciz "Hi ASM-World!\n" + .asciz "Hi ASM-World!\n" greeting_len: .int .-greeting </code></pre> @@ -7135,7 +7174,7 @@ x28-x31 t3-t6 temp regs #include <asm/unistd.h> // syscall NRs - .section .text, "ax", @progbits + .section .text, "ax", @progbits .balign 4 // align code on 4byte boundary .global _start _start: @@ -7150,9 +7189,9 @@ _start: ecall .balign 8 // align data on 8byte boundary - .section .rodata, "a", @progbits + .section .rodata, "a", @progbits greeting: - .asciz "Hi ASM-World!\n" + .asciz "Hi ASM-World!\n" greeting_len: .int .-greeting </code></pre> |