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- Initial cli documentation.

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# Now let's get this into the right place


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Markus Fischer 2002-05-10 21:11:05 +00:00
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features/commandline.xml
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@ -1,18 +1,632 @@
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.1 $ -->
<!--
TODO:
The command line options not in the
list, but in the -h output below:
-e, -z
It would be best to document these, and
collect more info about -c and -d!
-->
<!-- $Revision: 1.2 $ -->
<chapter id="features.commandline">
<title>Using PHP from the command line</title>
<!-- NEW DOCUMENTATION STARTS -->
<para>
Since version 4.3, <literal>PHP</literal> supports a new
<literal>SAPI</literal> type (Server Application Programming Interface)
named <literal>CLI</literal> which means <emphasis>Command Line
Interface</emphasis>. As the name implies, this <literal>SAPI</literal> type
main focus is on developing shell (or desktop as well) applications with
<literal>PHP</literal>. There are quite some differences between the
<literal>CLI SAPI</literal> and other <literal>SAPI</literal>s which are
further explained throughout this chapter.
</para>
<para>
The <literal>CLI SAPI</literal> was released for the first time with
<literal>PHP 4.2.0</literal>, but was still experimental back then and had
to be explicitely enabled with <literal>--enable-cli</literal> when running
<literal>./configure</literal>. Since <literal>PHP 4.3.0</literal> the
<literal>CLI SAPI</literal> is no longer experimental and is therefore
<emphasis role="strong">always</emphasis> built and installed as the
<filename>php</filename> (called <filename>php.exe</filename> on Windows)
binary.
</para>
<para>
Remarkable differences of the <literal>CLI SAPI</literal> compared to other
<literal>SAPI</literal>s:
<itemizedlist>
<listitem>
<para>
Unlikely the <literal>CGI SAPI</literal>, no headers are written to the
output.
</para>
<para>
Though the <literal>CGI SAPI</literal> provies a way to suppress HTTP
headers, there's not equivalent switch to enable them in the <literal>CLI
SAPI</literal>.
</para>
</listitem>
<listitem>
<para>
The are certain &php.ini; directives which are overriden by the <literal>CLI
SAPI</literal> because the do not make sense in shell environments:
<table>
<title>Overriden &php.ini; directives</title>
<tgroup cols="3">
<thead>
<row>
<entry>Directive</entry>
<entry><literal>CLI SAPI</literal> default value</entry>
<entry>Comment</entry>
</row>
</thead>
<tbody>
<row>
<entry><link linkend="ini.html-errors">html_errors</link></entry>
<entry>&false;</entry>
<entry>
It can be quite hard to read the error message in your shell when
it's cluttered with all those meaningless <literal>HTML</literal>
tags, therefore this directive defaults to &false;.
</entry>
</row>
<row>
<entry><link linkend="ini.implicit-flush">implicit_flush</link></entry>
<entry>&true;</entry>
<entry>
It is desired that any output coming from
<function>print</function>, <function>echo</function> and friends is
immidiately written to the output and not cached in any buffer.
</entry>
</row>
<row>
<entry><link linkend="ini.max-execution-time">max_execution_time</link></entry>
<entry>0 (unlimited)</entry>
<entry>
Due to endless possibilities of using <literal>PHP</literal> in
shell environments, the maximum execution time has been set to
unlimited. Whereas applications written for the web are executed
within splits of a seconds, shell application tend to have a much
longer execution time.
</entry>
</row>
<row>
<entry><link linkend="ini.register-argc-argv">register_argc_argv</link></entry>
<entry>&true;</entry>
<entry>
The global <literal>PHP</literal> variables <literal>$argc</literal>
(number of arguments passed to the application) and
<literal>$argv</literal> (array of the actual arguments) are always
registered and filled in with the appropriate values when using the
<literal>CLI SAPI</literal>.
</entry>
</row>
</tbody>
</tgroup>
</table>
</para>
<note>
<para>
This directives cannot be initialzied with another value from the
configuration file &php.ini; or a custom one (if specified). This is a
limitation because those default values are applied after all
configuration files have been parsed. However, their value can be changed
during runtime (which does not make sense for all of those directives,
e.g. <link linkend="ini.register-argc-argv">register_argc_argv</link>).
</para>
</note>
</listitem>
<listitem>
<para>
The <literal>CLI SAPI</literal> does <emphasis
role="strong">not</emphasis> change the current directory to the directory
of the executed script !
</para>
<para>
Example showing the difference to the <literal>CGI SAPI</literal>:
<programlisting role="php">
<![CDATA[
<?
/* Our simple test application */
echo getcwd(), "\n";
?>
]]>
</programlisting>
</para>
<para>
When using the <literal>CGI</literal> version, the output is
<screen>
<![CDATA[
$ pwd
/tmp
$ php-cgi -f another_directory/test.php
/tmp/another_directory
]]>
</screen>
This clearly shows that <literal>PHP</literal> changes its current
directory to the one of the executed script.
</para>
<para>
Using the <literal>CLI SAPI</literal> yields:
<screen>
<![CDATA[
$ pwd
/tmp
$ php -f another_directory/test.php
/tmp
]]>
</screen>
This allows for greater flexibility when writing shell tools in
<literal>PHP</literal>.
</para>
<note>
<para>
The <literal>CGI SAPI</literal> supports the <literal>CLI SAPI</literal>
behaviour by means of the <literal>-C</literal> switch when ran from the
command line.
</para>
</note>
</listitem>
</itemizedlist>
</para>
<para>
The list of command line options provided by the <literal>PHP</literal>
binary can be queryied anytime by running <literal>PHP</literal> with the
<literal>-h</literal> switch:
<screen>
<![CDATA[
Usage: php [options] [-f] <file> [args...]
php [options] -r <code> [args...]
php [options] [-- args...]
-s Display colour syntax highlighted source.
-w Display source with stripped comments and whitespace.
-f <file> Parse <file>.
-v Version number
-c <path>|<file> Look for php.ini file in this directory
-a Run interactively
-d foo[=bar] Define INI entry foo with value 'bar'
-e Generate extended information for debugger/profiler
-z <file> Load Zend extension <file>.
-l Syntax check only (lint)
-m Show compiled in modules
-i PHP information
-r <code> Run PHP <code> without using script tags <?..?>
-h This help
args... Arguments passed to script. Use -- args when first argument
starts with - or script is read from stdin
]]>
</screen>
</para>
<para>
The <literal>CLI SAPI</literal> has three different ways of getting the
<literal>PHP</literal> code you want to execute:
<orderedlist>
<listitem>
<para>
Telling <literal>PHP</literal> to execute a certain file.
</para>
<para>
<screen>
<![CDATA[
php my_script.php
php -f my_script.php
]]>
</screen>
Both ways (using the <literal>-f</literal> switch or not) execute the
given file <filename>my_script.php</filename>. You can choose any file to
execute, your <literal>PHP</literal> scripts do not have to end with the
<filename>.php</filename> extension but can give them any name or extension
you want them to have.
</para>
</listitem>
<listitem>
<para>
Pass the <literal>PHP</literal> code to execute directly on the command
line.
</para>
<para>
<screen>
<![CDATA[
php -r 'print_r(get_defined_constants());'
]]>
</screen>
Special care has to be taken in regards of shell variable substitution and
quoting usage.
</para>
<note>
<para>
Read the example carefully, thera are no beginning or end tags! The
<literal>-r</literal> switch simply does not need them. Using them will
lead to a parser error.
</para>
</note>
</listitem>
<listitem>
<para>
Provide the <literal>PHP</literal> code to execute via standard input
(<literal>stdin</literal>).
</para>
<para>
This gives the powerful ability to dynamically create
<literal>PHP</literal> code and feed it to the binary, as shown in this
(fictional) example:
<screen>
<![CDATA[
$ some_application | some_filter | php | sort -u >final_output.txt
]]>
</screen>
</para>
</listitem>
</orderedlist>
You cannot combine any of the three ways to execute code.
</para>
<para>
Like every shell application not only the <literal>PHP</literal> binary
accepts a number of arguments but also your <literal>PHP</literal> script
can receive them. The number of arguments which can be passed to your script
is not limited by <literal>PHP</literal> (the shell has a certain size limit
in numbers of characters which can be passed, usually you won't hit this
limit). The arguments passed to your script are available in the global
array <literal>$argv</literal>. The zero index always contains the script
name (which is <literal>-</literal> in case the <literal>PHP</literal> code
is coming from either standard input or from the command line switch
<literal>-r</literal>). The second registered global variable is
<literal>$argc</literal> which contains the number of elements in the
<literal>$argv</literal> array (<emphasis role="strong">not</emphasis> the
number of arguments passed to the script).
</para>
<para>
As long as the arguments you want to pass to your script do not start with
the <literal>-</literal> character, there's nothing special to whatch out
for. Passing an argument to your script which starts with a
<literal>-</literal> will cause trouble because <literal>PHP</literal>
thinks it has to handle it. To prevent this use the argument list separator
<literal>--</literal>. After argument has been parsed by
<literal>PHP</literal>, every argument following it is passed
untoched/unparsed to your script.
</para>
<screen>
<![CDATA[
# This will not execute the given code but will show the PHP usage
$ php -r 'var_dump($argv);' -h
Usage: php [options] [-f] <file> [args...]
[...]
# This will pass the '-h' argument to your script and prevent PHP from showing it's usage
$ php -r 'var_dump($argv);' -- -h
array(2) {
[0]=>
string(1) "-"
[1]=>
string(2) "-h"
}
]]>
</screen>
<para>
But, there's another way of using <literal>PHP</literal> for shell
scripting. You can write a script whose first line starts with
<literal>#!/usr/bin/php</literal> and then following the normal
<literal>PHP</literal> code included within the <literal>PHP</literal>
starting and end tags and set the execution attributes of the file
appropriately. This way it can be executed like a normal shell or perl
script:
<programlisting role="php">
<![CDATA[
#!/usr/bin/php
<?
var_dump($argv);
?>
]]>
</programlisting>
Assuming this file is named <filename>test</filename> in the current
directory, we can now do the following:
<screen>
<![CDATA[
$ chmod 755 test
$ ./test -h -- foo
array(4) {
[0]=>
string(6) "./test"
[1]=>
string(2) "-h"
[2]=>
string(2) "--"
[3]=>
string(3) "foo"
}
]]>
</screen>
As you see no care has to be taken when passing parameters to your script
which start with <literal>-</literal>.
</para>
<para>
<table>
<title>Command line options</title>
<tgroup cols="2">
<thead>
<row>
<entry>Option</entry>
<entry>Description</entry>
</row>
</thead>
<tbody>
<row>
<entry>-s</entry>
<entry>
<para>
Display colour syntax highlighted source.
</para>
<para>
This option uses the internal mechanism to parse the file and produces
a <literal>HTML</literal> highlighted version of it and writes it to
standard output. Note that all it does it to generate a block of
<literal>&lt;code&gt; [...] &lt;/code&gt;</literal>
<literal>HTML</literal> tags, no <literal>HTML</literal> headers.
</para>
<note>
<para>
This option does not work together with the <literal>-r</literal>
option.
</para>
</note>
</entry>
</row>
<row>
<entry>-w</entry>
<entry>
<para>
Display source with stripped comments and whitespace.
</para>
<note>
<para>
This option does not work together with the <literal>-r</literal>
option.
</para>
</note>
</entry>
</row>
<row>
<entry>-f</entry>
<entry>
<para>
Parses and executed the given filename to the <literal>-f</literal>
option. This switch is optional and can be left out. Only providing
the filename to execute is sufficient.
</para>
</entry>
</row>
<row>
<entry>-v</entry>
<entry>
<para>
Writes the PHP and Zend version to standard output, e.g.
<screen>
$ php -v
PHP 4.3.0-dev (cli)
Zend Engine v1.2.1, Copyright (c) 1998-2002 Zend Technologies
</screen>
</para>
</entry>
</row>
<row>
<entry>-c</entry>
<entry>
<para>
With this option one can either specify a directory where to look for
&php.ini; or you can specify a custom <literal>INI</literal> file
directly (which does not need to be named &php.ini;), e.g.:
<screen>
$ php -c /custom/directory/ my_script.php
$ php -c /custom/directory/custom-file.ini my_script.php
</screen>
</para>
</entry>
</row>
<row>
<entry>-a</entry>
<entry>
<para>
Runs PHP interactively.
<!--
mfischer, 20020510: Couldn't come up with a decent useful description
of the current implementation of the interactive mode.
-->
</para>
</entry>
</row>
<row>
<entry>-d</entry>
<entry>
<para>
This option allows to set a custom value for any of the configuration
directives allowed in &php.ini;. The syntax is:
<screen>
<![CDATA[
-d configuration_directive[=value]
]]>
</screen>
</para>
<para>
Examples:
<screen>
<![CDATA[
# Ommiting the value part will set the given configuration directive to "1"
$ php -d max_execution_time -r '$foo = ini_get("max_execution_time"); var_dump($foo);'
string(1) "1"
# Passing an empty value part will set the configuration directive to ""
php -d max_execution_time= -r '$foo = ini_get("max_execution_time"); var_dump($foo);'
string(0) ""
# The configuration directive will be set to anything passed after the '=' character
$ php -d max_execution_time=20 -r '$foo = ini_get("max_execution_time"); var_dump($foo);'
string(2) "20"
$ php -d max_execution_time=doesntmakesense -r '$foo = ini_get("max_execution_time"); var_dump($foo);'
string(15) "doesntmakesense"
]]>
</screen>
</para>
</entry>
</row>
<row>
<entry>-e</entry>
<entry>
<para>
Generate extended information for debugger/profiler.
<!--
mfischer, 20020510: Anyone who can provide more information what it
really does (even if it's only for developers) ?
-->
</para>
</entry>
</row>
<row>
<entry>-z</entry>
<entry>
<para>
Load Zend extension. If only a filename is given, PHP tries to load
this extension from the current default library path on your system
(usually specified <filename>/etc/ld.so.conf</filename> on Unix
systems). Passing a filename with an absolute path information will
not use the systems library search path. A relative filename with a
directory information will tell <literal>PHP</literal> only to try to
load the extension relative to the current directory.
</para>
</entry>
</row>
<row>
<entry>-l</entry>
<entry>
<para>
This option provides a convenient way to only perform a syntax check
on the given <literal>PHP</literal> code. On succes, the text
<literal>No syntax errors detected in &lt;filename&gt;</literal> is
written to standard output and the shell return code is
<literal>0</literal>. On failure, the text <literal>Errors parsing
&lt;filename&gt;</literal> in addition to the internal parser error
message is written to standard output and the shell return code is set
to <literal>255</literal>.
</para>
<para>
This option won't find fatal errors (like undefined functions). Use
<literal>-f</literal> if you would like to test for fatal errors too.
</para>
<note>
<para>
This option does not work together with the <literal>-r</literal>
option.
</para>
</note>
</entry>
</row>
<row>
<entry>-m</entry>
<entry>
<para>
Using this option, PHP prints out the built in (and loaded) PHP and
Zend modules:
<screen>
$ php -m
[PHP Modules]
xml
tokenizer
standard
session
posix
pcre
overload
mysql
mbstring
ctype
[Zend Modules]
</screen>
</para>
</entry>
</row>
<row>
<entry>-i</entry>
<entry>
This command line option calls <function>phpinfo</function>, and prints
out the results. If <literal>PHP</literal> is not working well, it is
advisable to make a <literal>php -i</literal> and see if any error
messages are printed out before or in place of the information tables.
Beware that the output is in <literal>HTML</literal> and therefore
quite huge.
</entry>
</row>
<row>
<entry>-r</entry>
<entry>
<para>
This option allows execution of <literal>PHP</literal> right from
within the command line. The <literal>PHP</literal> start and end tags
(<literal>&lt;?php</literal> and <literal>?&gt;</literal>) are
<emphasis role="strong">not needed</emphasis> and will cause a parser
errors.
</para>
<note>
<para>
Care has to be taken when using this form of <literal>PHP</literal>
to not collide with command line variable substitution done by the
shell.
</para>
<para>
Example showing a parser error
<screen>
<![CDATA[
$ php -r "$foo = get_defined_constants();"
Command line code(1) : Parse error - parse error, unexpected '='
]]>
</screen>
The problem here is that the shell performs variable substritution
even when using double quotes <literal>"</literal>. Since the
variable <literal>$foo</literal> is unlikely to be defined, it
expands to nothing which results in being the code passed to
<literal>PHP</literal> for executin in fact reads:
<screen>
<![CDATA[
$ php -r " = get_defined_constants();"
]]>
</screen>
The correct way would be to use single quotes <literal>'</literal>.
The shell doesn't expand variables in strings quoted with single
quotes:
<screen>
<![CDATA[
$ php -r '$foo = get_defined_constants(); var_dump($foo);'
array(370) {
["E_ERROR"]=>
int(1)
["E_WARNING"]=>
int(2)
["E_PARSE"]=>
int(4)
["E_NOTICE"]=>
int(8)
["E_CORE_ERROR"]=>
[...]
]]>
</screen>
One still can easily run intro troubles when trying to get shell
variables into the code or using backslashes for escaping. You've
been warned. <!-- :-) -->
</para>
</note>
</entry>
</row>
<row>
<entry>-h</entry>
<entry>
With this option, you can get information about the actual list of
command line options and some one line descriptions about what they do.
</entry>
</row>
</tbody>
</tgroup>
</table>
</para>
<!-- NEW DOCUMENTATION ENDS -->
<!-- OLD DOCUMENTED STARTS
mfischer, 20020510: I've commented out the start paragraphs of the old
documentation as it is meant to be replaced by the new one.
<para>
The command line options of the PHP executable are useful
if you would like to debug or test your PHP setup, but they
@ -179,18 +793,17 @@ Usage: php [-q] [-h] [-s [-v] [-i] [-f <file>] | {<file> [args...]}
</tgroup>
</table>
</para>
-->
<para>
The PHP executable can be used to run PHP scripts absolutely
independent from the web server. If you are on a Unix system,
you should add a special first line to your PHP script, and
make it executable, so the system will know, what program
should run the script. On a Windows platform you can associate
<literal>php.exe -q</literal> with the double click option of
the <literal>.php</literal> files, or you can make a batch file
to run the script through PHP. The first line added to the
script to work on Unix won't hurt on Windows, so you can write
cross platform programs this way. A simple example of writing
a command line PHP program can be found below.
The PHP executable can be used to run PHP scripts absolutely independent
from the web server. If you are on a Unix system, you should add a special
first line to your PHP script, and make it executable, so the system will
know, what program should run the script. On a Windows platform you can
associate <literal>php.exe</literal> with the double click option of the
<literal>.php</literal> files, or you can make a batch file to run the
script through PHP. The first line added to the script to work on Unix won't
hurt on Windows, so you can write cross platform programs this way. A simple
example of writing a command line PHP program can be found below.
</para>
<example>
<title>Script intended to be run from command line (script.php)</title>