Reference - Parms functions - substr

{set $s = 'hello'}[{echo trim('  a  ')}][{echo upper($s)}][{echo left($s, 2)}][{if upper($s) eq 'HELLO'}T{else}F{/if}][{echo 'x' . upper($s)}][{echo date('Y', 0)}][{echo $s | replace('l', upper('x'))}][{echo substr($s, 0, 3)}][{echo $s | left(2)}][{$s | left(3)}]

<?php

  $a   = 5;
  $b   = 3;
  $n   = 2;
  $neg = -4;

?>

[{echo 5 * -$b}][{echo $a - -$b}][{echo 5 * -(1 + 2)}][{echo 10 / -$n}][{echo 2 ** -$n}]
[{echo 5 * - 3}][{echo 2 - - 3}][{echo 3 - -$n * 2}][{echo 5 * -php:abs(3)}][{echo 1 + +$b}]
[{echo 10 | * -$n}][{echo 'abcdef' | substr(-$n)}][{echo 'abcdef' | substr(1, -$n)}][{echo php:max(1, -$n)}]
[{if $neg gt -$b}T{else}F{/if}][{echo -$b}][{echo 10 | - 3}]

<?php

  // A text with a byte that is no UTF-8, far before its end: it is cut in code points, as
  // the same text is when the byte stands near the end.

  $tail  = "ab\u{1F1F3}\u{1F1F1}e\u{301}";
  $long  = "\xFF" . str_repeat ( 'a', 5000 ) . $tail;
  $short = "\xFF" . str_repeat ( 'a', 10 ) . $tail;

?>

[{echo $long | right(1) | php:bin2hex(@)}][{echo $long | right(2) | php:bin2hex(@)}][{echo $long | substr(-3, 1) | php:bin2hex(@)}][{echo $short | right(1) | php:bin2hex(@)}]

{echo 'Zoë Müller' | left(3)}|{echo 'Zoë Müller' | right(6)}|{echo 'Zoë Müller' | mid(3, 3)}|{echo 'Zoë Müller' | substr(2, 3)}|{echo 'Zoë Müller' | max_len(3)}

<?php

  $len = '';

?>

[{echo 'Hello' | substr(1, $len)}][{echo 'Hello' | substr($len)}][{echo 'Hello' | max_len($len)}][{echo 'Hello' | substr(1.5)}]

{echo 'Hello World' | substr(6)}

{echo 'abcdef' | substr(-2)}

{echo 'abc' | substr(20)}

{echo 'Hello World' | substr(0, 5)}

<?php

  $flag = "\u{1F1F3}\u{1F1F1} NL";
  $nfd  = "e\u{0301}cole";
  $fam  = "a\u{1F468}\u{200D}\u{1F469}\u{200D}\u{1F467}";

?>

[{echo $flag | left(1) | php:bin2hex(@)}][{echo $nfd | left(1) | php:bin2hex(@)}][{echo $fam | right(1) | php:bin2hex(@)}][{echo $nfd | mid(2, 2)}][{echo $flag | max_len(1) | php:bin2hex(@)}][{echo $nfd | substr(1)}][{echo $nfd | truncate(3, '.') | php:bin2hex(@)}]

<?php

  // Past 4096 bytes right() and substr() from the end read a window at the end of the text,
  // not the whole of it: a run of flags, whose pairs count from the run's start, and an
  // accent written apart must come out whole there too.

  $flags  = str_repeat ( "\u{1F1F3}\u{1F1F1}", 3001 );
  $accent = str_repeat ( "e\u{0301}", 3000 ) . "ab";

?>

[{echo $flags | right(1) | php:bin2hex(@)}][{echo $flags | substr(-2, 1) | php:bin2hex(@)}][{echo $accent | right(3) | php:bin2hex(@)}][{echo $accent | mid(3000, 1) | php:bin2hex(@)}][{echo $accent | truncate(3, '') | php:bin2hex(@)}]

[{substr 0, 2}abcdef{/substr}][{trim}  x  {/trim}][{echo php:substr('abc', 1)}]

{content 'who'}
  {users}
    <p>@content@ by {$username}
  {/users}
  on {$created_at | substr (0, 16)}</p>
{/content}

{forum_topics $id=1}

  {forum_boards}
    <h1>Board: {$name}</h1>
  {/forum_boards}

  <h2>Topic: {$title}</h2>

  {who}Started{/who}

  {forum_posts}

    <hr>

    {who}Posted{/who}

    <p>{$content}</p>
  
  @else@
  
    <p>No posts yet</p>
  
  {/forum_posts}

{/forum_topics}