Manual:$wgPhpCli

Shell and process control: $wgPhpCli
Executable path of PHP cli client (php/php5).
Introduced in version:1.14.0 (r40069)
Removed in version:still in use
Allowed values:(string)
Default value:'/usr/bin/php' (1.16+)
'php' (1.14-1.15)

Details edit

Executable path of PHP cli client (php/php5).

If you're not sure what this should be set to then running whereis php, will locate the PHP binary for you.

Example edit

$wgPhpCli = '/usr/bin/php';