what is php-common and what does it do?
To answer the question, here's what's in php-common on Redhat Enterprise 6.4 version of the package:
[marc@foo ~]$ rpm -ql php-common
/etc/php.d
/etc/php.d/curl.ini
/etc/php.d/fileinfo.ini
/etc/php.d/json.ini
/etc/php.d/phar.ini
/etc/php.d/zip.ini
/etc/php.ini
/usr/lib64/php
/usr/lib64/php/modules
/usr/lib64/php/modules/curl.so
/usr/lib64/php/modules/fileinfo.so
/usr/lib64/php/modules/json.so
/usr/lib64/php/modules/phar.so
/usr/lib64/php/modules/zip.so
/usr/lib64/php/pear
/usr/share/doc/php-common-5.3.3
/usr/share/doc/php-common-5.3.3/CODING_STANDARDS
/usr/share/doc/php-common-5.3.3/CREDITS
/usr/share/doc/php-common-5.3.3/EXTENSIONS
/usr/share/doc/php-common-5.3.3/INSTALL
/usr/share/doc/php-common-5.3.3/LICENSE
/usr/share/doc/php-common-5.3.3/NEWS
/usr/share/doc/php-common-5.3.3/README.EXTENSIONS
/usr/share/doc/php-common-5.3.3/README.EXT_SKEL
/usr/share/doc/php-common-5.3.3/README.MAILINGLIST_RULES
/usr/share/doc/php-common-5.3.3/README.PARAMETER_PARSING_API
/usr/share/doc/php-common-5.3.3/README.PHP4-TO-PHP5-THIN-CHANGES
/usr/share/doc/php-common-5.3.3/README.REDIST.BINS
/usr/share/doc/php-common-5.3.3/README.RELEASE_PROCESS
/usr/share/doc/php-common-5.3.3/README.SELF-CONTAINED-EXTENSIONS
/usr/share/doc/php-common-5.3.3/README.STREAMS
/usr/share/doc/php-common-5.3.3/README.SUBMITTING_PATCH
/usr/share/doc/php-common-5.3.3/README.SVN-RULES
/usr/share/doc/php-common-5.3.3/README.TESTING
/usr/share/doc/php-common-5.3.3/README.TESTING2
/usr/share/doc/php-common-5.3.3/README.UNIX-BUILD-SYSTEM
/usr/share/doc/php-common-5.3.3/README.WIN32-BUILD-SYSTEM
/usr/share/doc/php-common-5.3.3/README.input_filter
/usr/share/doc/php-common-5.3.3/README.namespaces
/usr/share/doc/php-common-5.3.3/TSRM_LICENSE
/usr/share/doc/php-common-5.3.3/ZEND_CHANGES
/usr/share/doc/php-common-5.3.3/ZEND_LICENSE
/usr/share/doc/php-common-5.3.3/php.ini-development
/usr/share/doc/php-common-5.3.3/php.ini-production
/usr/share/doc/php-common-5.3.3/regex_COPYRIGHT
/usr/share/php
/var/lib/php
As you can see, it basically contains the .so modules for curl
, zip
, fileinfo
, json
, and phar
, plus license/support files.