{"id":1136,"date":"2025-06-04T15:05:26","date_gmt":"2025-06-04T14:05:26","guid":{"rendered":"https:\/\/workboot.fr\/ciela\/?page_id=1136"},"modified":"2025-07-12T15:54:30","modified_gmt":"2025-07-12T14:54:30","slug":"les-codages","status":"publish","type":"page","link":"https:\/\/workboot.fr\/ciela\/les-codages\/","title":{"rendered":"Les codages"},"content":{"rendered":"\n<nav aria-label=\"Table des mati\u00e8res\" class=\"wp-block-table-of-contents\"><ol><li><a class=\"wp-block-table-of-contents__entry\" href=\"https:\/\/workboot.fr\/ciela\/les-codages\/#ascii\">ASCII<\/a><ol><li><a class=\"wp-block-table-of-contents__entry\" href=\"https:\/\/workboot.fr\/ciela\/les-codages\/#ascii-etendu-au-dessus-de-128-codes-128-a-255-contexte-francais\">\ud83c\uddeb\ud83c\uddf7 ASCII \u00e9tendu au-dessus de 128 (codes 128 \u00e0 255) \u2013 Contexte fran\u00e7ais<\/a><\/li><\/ol><\/li><li><a class=\"wp-block-table-of-contents__entry\" href=\"https:\/\/workboot.fr\/ciela\/les-codages\/#utf8\">UTF8<\/a><ol><li><a class=\"wp-block-table-of-contents__entry\" href=\"https:\/\/workboot.fr\/ciela\/les-codages\/#metaphore-pour-faciliter\">\ud83d\udcac M\u00e9taphore pour faciliter<\/a><\/li><li><a class=\"wp-block-table-of-contents__entry\" href=\"https:\/\/workboot.fr\/ciela\/les-codages\/#resume-pour-retenir\">\ud83c\udfaf R\u00e9sum\u00e9 pour retenir<\/a><\/li><\/ol><\/li><li><a class=\"wp-block-table-of-contents__entry\" href=\"https:\/\/workboot.fr\/ciela\/les-codages\/#exercice-sous-linux\">Exercice sous linux<\/a><\/li><\/ol><\/nav>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"ascii\">ASCII<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>ASCII<\/strong> (American Standard Code for Information Interchange) est une norme qui permet de repr\u00e9senter des <strong>caract\u00e8res<\/strong> (lettres, chiffres, symboles, etc.) sous forme de <strong>valeurs num\u00e9riques<\/strong> que les ordinateurs peuvent traiter.<\/p>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\" hidden class=\"wp-block-file__embed\" data=\"https:\/\/workboot.fr\/ciela\/wp-content\/uploads\/2025\/06\/Table_ASCII_complete.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"Contenu embarqu\u00e9 Table_ASCII_compl\u00e8te.\"><\/object><a id=\"wp-block-file--media-5e1a98fc-aa1d-4af3-ac64-f264d91dc49c\" href=\"https:\/\/workboot.fr\/ciela\/wp-content\/uploads\/2025\/06\/Table_ASCII_complete.pdf\">Table_ASCII_compl\u00e8te<\/a><a href=\"https:\/\/workboot.fr\/ciela\/wp-content\/uploads\/2025\/06\/Table_ASCII_complete.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-5e1a98fc-aa1d-4af3-ac64-f264d91dc49c\">T\u00e9l\u00e9charger<\/a><\/div>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"ascii-etendu-au-dessus-de-128-codes-128-a-255-contexte-francais\">\ud83c\uddeb\ud83c\uddf7 <strong>ASCII \u00e9tendu au-dessus de 128 (codes 128 \u00e0 255) \u2013 Contexte fran\u00e7ais<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Le <strong>code ASCII standard<\/strong> s&rsquo;arr\u00eate \u00e0 <strong>127<\/strong>, mais pour repr\u00e9senter des caract\u00e8res sp\u00e9cifiques \u00e0 des langues comme le <strong>fran\u00e7ais<\/strong> (accents, c\u00e9dilles, symboles mon\u00e9taires, etc.), on utilise une <strong>extension de l&rsquo;ASCII<\/strong> sur <strong>8 bits<\/strong> (donc de 128 \u00e0 255).<\/p>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\" hidden class=\"wp-block-file__embed\" data=\"https:\/\/workboot.fr\/ciela\/wp-content\/uploads\/2025\/06\/Table_ASCII_etendu_128-255_Windows-1252.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"Contenu embarqu\u00e9 Table_ASCII_etendu_128-255_Windows-1252.\"><\/object><a id=\"wp-block-file--media-6503d2b2-5f94-4ba7-ad29-52c5013a1bb4\" href=\"https:\/\/workboot.fr\/ciela\/wp-content\/uploads\/2025\/06\/Table_ASCII_etendu_128-255_Windows-1252.pdf\">Table_ASCII_etendu_128-255_Windows-1252<\/a><a href=\"https:\/\/workboot.fr\/ciela\/wp-content\/uploads\/2025\/06\/Table_ASCII_etendu_128-255_Windows-1252.pdf\" class=\"wp-block-file__button wp-element-button\" download aria-describedby=\"wp-block-file--media-6503d2b2-5f94-4ba7-ad29-52c5013a1bb4\">T\u00e9l\u00e9charger<\/a><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">sous linux on dispose de <\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>man ascii\n#un extrait du man :<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>Tableaux\n       Pour plus de commodit\u00e9, voici des tables plus compactes en  hexad\u00e9cimal\n       et en d\u00e9cimal.\n\n          2 3 4 5 6 7       30 40 50 60 70 80 90 100 110 120\n        -------------      ---------------------------------\n       0:   0 @ P ` p     0:    (  2  &lt;  F  P  Z  d   n   x\n       1: ! 1 A Q a q     1:    )  3  =  G  Q  &#91;  e   o   y\n       2: \" 2 B R b r     2:    *  4  &gt;  H  R  \\  f   p   z\n       3: # 3 C S c s     3: ! +  5  ? I  S  ]  g   q   {\n       4: $ 4 D T d t     4: \"  ,  6  @  J  T  ^  h   r   |\n       5: % 5 E U e u     5: #  -  7  A  K  U  _  i   s   }\n       6: &amp; 6 F V f v     6: $  . 8  B  L  V  `  j   t   ~\n       7: ' 7 G W g w     7: %  \/  9  C  M  W  a  k   u  DEL\n       8: ( 8 H X h x     8: &amp;  0  :  D  N  X  b  l   v\n       9: ) 9 I Y i y     9: '  1  ;  E  O  Y  c  m   w\n       A: * : J Z j z\n       B: + ; K &#91; k {\n       C: , &lt; L \\ l |\n       D: - = M ] m }\n       E: . &gt; N ^ n ~\n       F: \/ ? O _ o DEL<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"utf8\">UTF8<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Les <strong>128 premiers caract\u00e8res de UTF-8 = ASCII<\/strong> pur.\n<ul class=\"wp-block-list\">\n<li><code>A = 65 = 01000001<\/code> \u2192 en UTF-8 : <strong>1 octet identique<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>UTF-8 est donc <strong>r\u00e9trocompatible<\/strong> avec ASCII.<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Plage Unicode<\/th><th>Longueur en UTF-8<\/th><th>Exemple<\/th><\/tr><\/thead><tbody><tr><td>U+0000 \u00e0 U+007F<\/td><td>1 octet<\/td><td><code>A<\/code>, <code>a<\/code>, <code>0<\/code>, etc.<\/td><\/tr><tr><td>U+0080 \u00e0 U+07FF<\/td><td>2 octets<\/td><td><code>\u00e9<\/code>, <code>\u00e7<\/code>, <code>\u00f1<\/code><\/td><\/tr><tr><td>U+0800 \u00e0 U+FFFF<\/td><td>3 octets<\/td><td><code>\u20ac<\/code>, <code>\u0905<\/code>, <code>\u65e5<\/code><\/td><\/tr><tr><td>U+10000 et +<\/td><td>4 octets<\/td><td><code>\ud800\udf48<\/code>, <code>\ud83d\ude04<\/code>, etc.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Caract\u00e8re<\/th><th>ASCII (binaire)<\/th><th>UTF-8 (binaire)<\/th><\/tr><\/thead><tbody><tr><td>A<\/td><td><code>01000001<\/code><\/td><td><code>01000001<\/code><\/td><\/tr><tr><td>\u00e9<\/td><td>\u2014<\/td><td><code>11000011 10101001<\/code><\/td><\/tr><tr><td>\u20ac<\/td><td>\u2014<\/td><td><code>11100010 10000010 10101100<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"metaphore-pour-faciliter\">\ud83d\udcac M\u00e9taphore pour faciliter<\/h3>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Nombre d\u2019octets<\/th><th>Premier octet (bits de poids forts)<\/th><th>Description<\/th><\/tr><\/thead><tbody><tr><td>1 octet<\/td><td>0xxxxxxx<\/td><td>Caract\u00e8re ASCII standard (0-127)<\/td><\/tr><tr><td>2 octets<\/td><td>110xxxxx<\/td><td>Premier octet d\u2019un caract\u00e8re sur 2 octets<\/td><\/tr><tr><td>3 octets<\/td><td>1110xxxx<\/td><td>Premier octet d\u2019un caract\u00e8re sur 3 octets<\/td><\/tr><tr><td>4 octets<\/td><td>11110xxx<\/td><td>Premier octet d\u2019un caract\u00e8re sur 4 octets<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>ASCII<\/strong>, c\u2019est un petit tiroir \u00e0 128 cases.<br><strong>UTF-8<\/strong>, c\u2019est une <strong>commode extensible<\/strong> : elle garde les 128 premi\u00e8res cases intactes, mais ajoute des <strong>tiroirs suppl\u00e9mentaires \u00e0 ouverture variable<\/strong> (1 \u00e0 4 octets selon le caract\u00e8re).<\/p>\n<\/blockquote>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"resume-pour-retenir\">\ud83c\udfaf R\u00e9sum\u00e9 pour retenir<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u2705 <strong>UTF-8 contient ASCII<\/strong><\/li>\n\n\n\n<li>\u2705 G\u00e8re tous les alphabets du monde<\/li>\n\n\n\n<li>\u2705 Flexible (1 \u00e0 4 octets par caract\u00e8re)<\/li>\n\n\n\n<li>\u2705 Standard universel sur le web aujourd\u2019hui<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Le site officiel :<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/unicode.org\/emoji\/charts\/full-emoji-list.html\">https:\/\/unicode.org\/emoji\/charts\/full-emoji-list.html<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"exercice-sous-linux\">Exercice sous linux<\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>bruno@elliott:~\/Works\/utf$ cat emoji.txt\n\ud83d\ude02\n\u00ea\n\u00e9\n\u00e8\n\u00e0\n@<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>bruno@elliott:~\/Works\/utf$ hexdump -C emoji.txt \n00000000  <mark style=\"background-color:rgba(0, 0, 0, 0);color:#cf2e2e\" class=\"has-inline-color\">f0 9f 98 82<\/mark> 0a <mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">c3 aa<\/mark> 0a  <mark style=\"background-color:rgba(0, 0, 0, 0);color:#00d084\" class=\"has-inline-color\">c3 a9<\/mark> 0a <mark style=\"background-color:rgba(0, 0, 0, 0);color:#9b51e0\" class=\"has-inline-color\">c3 a8<\/mark> 0a <mark style=\"background-color:rgba(0, 0, 0, 0);color:#7bdcb5\" class=\"has-inline-color\">c3 a0<\/mark>  |................|\n00000010  0a <mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-2-color\">40<\/mark> 0a 0a                                       |.@..|\n00000014\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">on voit nettement que le smiley c&rsquo;est 0xf0  0x9f 0x98 0x82   4 octets<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>0x82 : 1000 0010 (2)\n0x98 : 1001 0010 (2)\n0x9f : 1001 1111 (2)\n0xf0 : 1111 0000 (2)<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>ASCII ASCII (American Standard Code for Information Interchange) est une norme qui permet de repr\u00e9senter des caract\u00e8res (lettres, chiffres, symboles, etc.) sous forme de valeurs num\u00e9riques que les ordinateurs peuvent traiter. \ud83c\uddeb\ud83c\uddf7 ASCII \u00e9tendu au-dessus de 128 (codes 128 \u00e0 255) \u2013 Contexte fran\u00e7ais Le code ASCII standard s&rsquo;arr\u00eate \u00e0 127, mais pour repr\u00e9senter des [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","footnotes":""},"class_list":["post-1136","page","type-page","status-publish","hentry"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"admin","author_link":"https:\/\/workboot.fr\/ciela\/author\/admin\/"},"uagb_comment_info":0,"uagb_excerpt":"ASCII ASCII (American Standard Code for Information Interchange) est une norme qui permet de repr\u00e9senter des caract\u00e8res (lettres, chiffres, symboles, etc.) sous forme de valeurs num\u00e9riques que les ordinateurs peuvent traiter. \ud83c\uddeb\ud83c\uddf7 ASCII \u00e9tendu au-dessus de 128 (codes 128 \u00e0 255) \u2013 Contexte fran\u00e7ais Le code ASCII standard s&rsquo;arr\u00eate \u00e0 127, mais pour repr\u00e9senter des\u2026","_links":{"self":[{"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/pages\/1136","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/comments?post=1136"}],"version-history":[{"count":11,"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/pages\/1136\/revisions"}],"predecessor-version":[{"id":2319,"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/pages\/1136\/revisions\/2319"}],"wp:attachment":[{"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/media?parent=1136"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}