Following commands can be use to check the syntax of the configuration files of different services:
1) To check the syntax of APACHE:
httpd -t
In order to check the syntax of virtualhost:
httpd -t -D DUMP_VHOSTS
2)To check syntax for DNS:
a) checking syntax errors in the main configuration file..
named-checkconf main-config-file
main-config-file : Mention the path of the main configuration file.
b)To check the zone file for a domain.
named-checkzone domain zonefile-location
zonefile-location: The exact location of the zone file to be checked
3)To check syntax of SAMBA:
testparm
4)To check syntax of SQUID server:
squid -k check squid -k parse