Section 12.4. CLI Environment

12.4. CLI Environment

PEAR lets you include command-line scripts in a package. However, when doing so, you will quickly run into configuration problems like, "Which include_path should I use here" or "What is the full path of the PHP executable that should be used?" This information may be specified by users in a set of environment variables, as shown in Table 12.1.

Table 12.1. PEAR Installer Environment Variables

Environment Variable	Corresponding Configuration Parameter
PHP_PEAR_SYSCONF_DIR	none
PHP_PEAR_MASTER_SERVER	master_server
PHP_PEAR_HTTP_PROXY	http_proxy
PHP_PEAR_INSTALL_DIR	php_dir
PHP_PEAR_EXTENSION_DIR	ext_dir
PHP_PEAR_DOC_DIR	doc_dir
PHP_PEAR_BIN_DIR	bin_dir
PHP_PEAR_DATA_DIR	data_dir
PHP_PEAR_TEST_DIR	test_dir
PHP_PEAR_CACHE_DIR	cache_dir
PHP_PEAR_PHP_BIN	php_bin
PHP_PEAR_VERBOSE	verbose
PHP_PEAR_PREFERRED_STATE	preferred_state
PHP_PEAR_UMASK	umask
PHP_PEAR_CACHE_TTL	cache_ttl
PHP_PEAR_SIG_TYPE	sig_type
PHP_PEAR_SIG_BIN	sig_bin
PHP_PEAR_SIG_KEYDIR	sig_keydir

If any of this information is needed during bootstrapping of a PHP script, these environment variables should be used. The PEAR installer uses these environment variables when it sets up default values for its configuration parameters.

Here is an example of a UNIX command-line scripts, using the PHP_PEAR_PHP_BIN environment variable to find the right PHP binary:

 #!/bin/sh export PHP_PEAR_PHP_BIN=${PHP_PEAR_PHP_BIN:-php} exec $PHP_PEAR_PHP_BIN d output_buffering=1 $0 $@ <?php ob_end_clean(); print "PHP " . phpversion() . " on " . php_uname() . "\n"; 

• PHP embedded in UNIX shell script. What happens here is that the PHP_PEAR_PHP_BIN is set to either its current existing value or to php if it is not set. Then, the shell script exec's (replaces itself with) PHP with a parameter that enables output buffering, followed by the name of the script and all the command-line parameters. When PHP starts executing the file, it would normally just display the second and third line with shell script code, but because it is running with output buffering enabled, these lines are just buffered. In the PHP block, ob_end_clean() ends output buffering and discards the output so far, so PHP never displays the shell code:

   @echo off if "%OS"=="Windows_NT" @setlocal if "%PHP_PEAR_PHP_BIN%"=="" goto useDefault goto run :useDefault set PHP_PEAR_PHP_BIN=php.exe :run %PHP_PEAR_PHP_BIN% -d output_buffering=1 %~dp0 %1 %2 %3 %4 %5 %6 %7  %8 %9 <?php ob_end_clean(); print "PHP " . phpversion() . " on " . php_uname() . "\n"; 

  
  

• PHP embedded in a Windows .bat file. The basic approach here is the same as in the UNIX shell example. The PHP_PEAR_PHP_BIN environment variable is used to getting the right PHP executable, defaulting to just php.exe. (One limitation to note for .bat scripts is that you cannot pass more than nine parameters.)