I got the bellow result in the terminal on OSX

macpro-terminal$ whoami
testuser

macpro-terminal$ groups
staff com.apple.access_screensharing everyone _appstore localaccounts _appserverusr admin _appserveradm _lpadmin _lpoperator _developer com.apple.sharepoint.group.1

macpro-terminal$ security list-keychains
"/Users/testuser/Library/Keychains/login.keychain" "/Library/Keychains/System.keychain"

macpro-terminal$ xcodebuild -project my.xcodeproj .........
......(build result)..........
Build success

but, I got the different result in PHP code on OSX apache

test.php

    $cpCommand = "whoami";
    $output = shell_exec($cpCommand);
    echo $output;

    $cpCommand = "groups";
    $output = shell_exec($cpCommand);
    echo $output;

    $cpCommand = "security list-keychains";
    $output = shell_exec($cpCommand);
    echo $output;

    $cpCommand = "xcodebuild -project my.xcodeproj ...........";
    $output = shell_exec($cpCommand);
    echo $output;

Resultado

testuser

staff com.apple.access_screensharing everyone _appstore localaccounts _appserverusr admin _appserveradm _lpadmin _lpoperator _developer com.apple.sharepoint.group.1

"/Library/Keychains/System.keychain"
"/Library/Keychains/apsd.keychain"
"/Library/Keychains/System.keychain"
(comment : /Users/testuser/Library/Keychains/login.keychain -> is not exist)

[BEROR]Code Sign error: The identity 'iPhone Distribution: testuser Co.,Ltd' doesn't match any valid, non-expired certificate/private key pair in your keychains

Build failed

I tried OS X 10.8 (mountain lion),built in apache2 & PHP.
¿Cuál es el problema?
How can I get the same result of "security" command in PHP code & in terminal on OSX apache?

Gracias por su atención.