cvs: /phpdoc/language operators.sgml /phpdoc/functions exec.sgml

cslawi Mon Nov 15 05:03:17 1999 EDT Modified files: /phpdoc/language operators.sgml /phpdoc/functions exec.sgml Log: Added backtick operator and some crossrefs. Index: phpdoc/language/operators.sgml diff -u phpdoc/language/operators.sgml:1.4 phpdoc/language/operators.sgml:1.5 --- phpdoc/language/operators.sgml:1.4 Mon Nov 15 04:32:18 1999 +++ phpdoc/language/operators.sgml Mon Nov 15 05:03:15 1999 @@ -59,19 +59,6 @@ </simpara> --></sect1> - <sect1 id="language.operators.string"> - <title>String Operators</title> - <simpara> - There is only really one string operator -- the concatenation - operator ("."). - </simpara> - <para> - <informalexample><programlisting> -$a = "Hello "; -$b = $a . "World!"; // now $b = "Hello World!" - </programlisting></informalexample> - </para></sect1> - <sect1 id="language.operators.assignment"> <title>Assignment Operators</title> <simpara> @@ -110,7 +97,7 @@ up pointing at the same data, and nothing is copied anywhere. </para> -</sect1> + </sect1> <sect1 id="language.operators.bitwise"> <title>Bitwise Operators</title> @@ -162,60 +149,38 @@ </row> </tbody> </tgroup> - </table></sect1> + </table> + </sect1> - <sect1 id="language.operators.logical"> - <title>Logical Operators</title> - <table> - <title>Logical Operators</title> - <tgroup cols="3"> - <thead> - <row> - <entry>example</entry> - <entry>name</entry> - <entry>result</entry> - </row> - </thead> - <tbody> - <row> - <entry>$a and $b</entry> - <entry>And</entry> - <entry>True of both $a and $b are true.</entry> - </row> - <row> - <entry>$a or $b</entry> - <entry>Or</entry> - <entry>True if either $a or $b is true.</entry> - </row> - <row> - <entry>$a xor $b</entry> - <entry>Or</entry> - <entry>True if either $a or $b is true, but not both.</entry> - </row> - <row> - <entry>! $a</entry> - <entry>Not</entry> - <entry>True if $a is not true.</entry> - </row> - <row> - <entry>$a &amp;&amp; $b</entry> - <entry>And</entry> - <entry>True of both $a and $b are true.</entry> - </row> - <row> - <entry>$a || $b</entry> - <entry>Or</entry> - <entry>True if either $a or $b is true.</entry> - </row> - </tbody> - </tgroup> - </table> + <sect1 id="language.operators.execution"> + <title>Execution Operators</title> + + <para> + PHP supports one execution operator: backticks (``). Note that + these are not single-quotes! PHP will attempt to execute the + contents of the backticks as a shell command; the output will be + returned (i.e., it won't simply be dumped to output; it can be + assigned to a variable). + + <informalexample> + <programlisting role="php"> +$output = ls -al; +echo "&lt;pre&gt;$output&lt;/pre&gt;"; + </programlisting> + </informalexample> - <simpara> - The reason for the two different variations of "and" and "or" - operators is that they operate at different precedences. (See below.) - </simpara></sect1> + </para> + + <para> + See also <function>system</function>, + <function>passthru</function>, <function>exec</function>, + <function>popen</function>, and + <function>escapeshellcmd</function>. + </para> + + </sect1> + <sect1 id="language.operators.comparison"> <title>Comparison Operators</title> @@ -225,7 +190,7 @@ </simpara> <table> - <title>Comparson Operators</title> + <title>Comparison Operators</title> <tgroup cols="3"> <thead> <row> @@ -275,8 +240,64 @@ <informalexample><programlisting>(expr1) ? (expr2) : (expr3);</programlisting></informalexample> This expression returns to <replaceable>expr2</replaceable> if <replaceable>expr1</replaceable> evalutes to true, and expr3 if - <replaceable>expr1</replaceable> evaluates to false.</para></sect1> + <replaceable>expr1</replaceable> evaluates to false. + </para> + </sect1> + + + <sect1 id="language.operators.logical"> + <title>Logical Operators</title> + <table> + <title>Logical Operators</title> + <tgroup cols="3"> + <thead> + <row> + <entry>example</entry> + <entry>name</entry> + <entry>result</entry> + </row> + </thead> + <tbody> + <row> + <entry>$a and $b</entry> + <entry>And</entry> + <entry>True of both $a and $b are true.</entry> + </row> + <row> + <entry>$a or $b</entry> + <entry>Or</entry> + <entry>True if either $a or $b is true.</entry> + </row> + <row> + <entry>$a xor $b</entry> + <entry>Or</entry> + <entry>True if either $a or $b is true, but not both.</entry> + </row> + <row> + <entry>! $a</entry> + <entry>Not</entry> + <entry>True if $a is not true.</entry> + </row> + <row> + <entry>$a &amp;&amp; $b</entry> + <entry>And</entry> + <entry>True of both $a and $b are true.</entry> + </row> + <row> + <entry>$a || $b</entry> + <entry>Or</entry> + <entry>True if either $a or $b is true.</entry> + </row> + </tbody> + </tgroup> + </table> + + <simpara> + The reason for the two different variations of "and" and "or" + operators is that they operate at different precedences. (See below.) + </simpara></sect1> + <sect1 id="language.operators.precedence"> <title>Operator Precedence</title> <para> @@ -382,6 +403,21 @@ </tbody> </tgroup> </table></para></sect1> + + <sect1 id="language.operators.string"> + <title>String Operators</title> + <simpara> + There is only really one string operator -- the concatenation + operator ("."). + </simpara> + <para> + <informalexample><programlisting> +$a = "Hello "; +$b = $a . "World!"; // now $b = "Hello World!" + </programlisting></informalexample> + </para> + </sect1> + </chapter> Index: phpdoc/functions/exec.sgml diff -u phpdoc/functions/exec.sgml:1.3 phpdoc/functions/exec.sgml:1.4 --- phpdoc/functions/exec.sgml:1.3 Wed Oct 20 18:41:42 1999 +++ phpdoc/functions/exec.sgml Mon Nov 15 05:03:16 1999 @@ -14,17 +14,28 @@ <paramdef>string <parameter>command</parameter></paramdef> </funcsynopsis> <para> - <function>EscapeShellCmd</function> escapes any characters in a string that - might be used to trick a shell command into executing arbitrary commands. - This function should be used to make sure that any data coming from user - input is escaped before this data is passed to the <function>exec</function> or <function>system</function> - functions. A standard use would be:</para> + <function>EscapeShellCmd</function> escapes any characters in a + string that might be used to trick a shell command into executing + arbitrary commands. This function should be used to make sure + that any data coming from user input is escaped before this data + is passed to the <function>exec</function> or + <function>system</function> functions, or to the <link + linkend="language.operators.execution">backtick + operator</link>. A standard use would be:</para> <para> <informalexample> <programlisting> system(EscapeShellCmd($cmd)) </programlisting> - </informalexample></para> + </informalexample> + </para> + + <para> + See also <function>exec</function>, <function>popen</function>, + <function>system</function>, and the <link + linkend="language.operators.execution">backtick operator</link>. + </para> + </refsect1> </refentry> @@ -62,9 +73,13 @@ Note that if you are going to allow data coming from user input to be passed to this function, then you should be using <function>EscapeShellCmd</function> to make sure that users cannot trick the system into executing arbitrary commands.</para> + <para> - See also <function>system</function>, <function>PassThru</function>, - <function>popen</function> and <function>EscapeShellCmd</function>.</para> + See also <function>system</function>, + <function>PassThru</function>, <function>popen</function>, + <function>EscapeShellCmd</function>, and the <link + linkend="language.operators.execution">backtick operator</link>. + </para> </refsect1> </refentry> @@ -95,7 +110,14 @@ <para> If you need to execute a command and have all the data from the command passed directly back without any interference, use the <function>PassThru</function> - function. See also the <function>exec</function> and <function>popen</function> functions.</para> + function. + </para> + <para> + See also <function>exec</function>, + <function>PassThru</function>, <function>popen</function>, + <function>EscapeShellCmd</function>, and the <link + linkend="language.operators.execution">backtick operator</link>. + </para> </refsect1> </refentry> @@ -126,7 +148,11 @@ then calling a pbmplus program to output a gif, you can create PHP scripts that output images directly.</para> <para> - See also <function>exec</function> and <function>fpassthru</function>.</para> + See also <function>exec</function>, + <function>PassThru</function>, <function>popen</function>, + <function>EscapeShellCmd</function>, and the <link + linkend="language.operators.execution">backtick operator</link>. + </para> </refsect1> </refentry>