https://community.hpe.com/t5/operating-system-linux/macro-definitions-in-m4/m-p/3740220#M101279 Hello,<BR /> <BR />I haven't done any m4 scripting before.<BR />Nevertheless, I have been presumptuous enough<BR />to believe that it only takes a little read of the m4 manpage to get me going.<BR /> <BR />Not quite...<BR /> <BR /> <BR />Though this is excercised on a Linux Heartbeat cluster which serves an Apache I think it isn't really OS specific and equally applies to m4 on HP-UX.<BR /> <BR />I simply want to define an IP based virtual host container that should bind its listening socket to the current node's IP address.<BR />Thus I thought this could easily be placed in an m4 template which is to be parsed by m4 through the Heartbeat Apache resource start/stop script right before it fires up the webserver, in order to produce that virtual host container with the fitting IP address.<BR /> <BR />You might ask what this is good for.<BR />The productive webserver has its fixed IP address that travels together with the package <BR />(the same as ServiceGuard's relocative IP).<BR />This additional webserver is only required for maintenance of the cluster nodes.<BR />E.g. I mirrored a MiniCPAN (abt. 400MB) which I want to have serviced by the virtual host<BR />in case should immediate installation of additional CPAN modules be required on the cluster nodes.<BR /> <BR />Ok, here's the m4 mess I have started with,<BR />but somehow I think I haven't apprehended the notion of m4 yet.<BR />I thought it should be possible to simply assign a "macro", very much like a variable in any scripting language, only to be referrenced later.<BR />But this doesn't work in my definition of get_ip.<BR />You see, I don't want to repeat the long parsing command to retreive the IP address everywhere in situ where it is required.<BR /> <BR />When I have run this through m4<BR /> <BR /> <BR /> <BR /># cat vhosts.conf.mc <BR />define(`get_ip' , /sbin/ifconfig eth0|awk -F: '$1~/inet addr/{print$2}'|tr -cd '[0-9.]')<BR /><VIRTUALHOST syscmd=""><BR /> ServerName syscmd(/sbin/ifconfig eth0|awk -F: '$1~/inet addr/{print$2}'|tr -cd '[0-9.]'):ifdef(`PO<BR />RT', `PORT', 80)<BR /> ServerAdmin root@syscmd(/sbin/ifconfig eth0|awk -F: '$1~/inet addr/{print$2}'|tr -cd '[0-9.]')<BR /></VIRTUALHOST><BR /> <BR /> <BR />then this is what I get<BR /> <BR /> <BR /># m4 -DPORT=443 vhosts.conf.mc <BR /> <BR /><VIRTUALHOST></VIRTUALHOST>:443&gt;<BR /> ServerName 192.168.2.2:443<BR /> ServerAdmin root@192.168.2.2<BR /><BR /> <BR /> <BR />So how do m4 definitions are applied correctly?<BR /> <BR />Regards<BR />Ralph<BR /> Mon, 27 Feb 2006 12:44:37 GMT Ralph Grothe 2006-02-27T12:44:37Z https://community.hpe.com/t5/operating-system-linux/macro-definitions-in-m4/m-p/3740220#M101279 Hello,<BR /> <BR />I haven't done any m4 scripting before.<BR />Nevertheless, I have been presumptuous enough<BR />to believe that it only takes a little read of the m4 manpage to get me going.<BR /> <BR />Not quite...<BR /> <BR /> <BR />Though this is excercised on a Linux Heartbeat cluster which serves an Apache I think it isn't really OS specific and equally applies to m4 on HP-UX.<BR /> <BR />I simply want to define an IP based virtual host container that should bind its listening socket to the current node's IP address.<BR />Thus I thought this could easily be placed in an m4 template which is to be parsed by m4 through the Heartbeat Apache resource start/stop script right before it fires up the webserver, in order to produce that virtual host container with the fitting IP address.<BR /> <BR />You might ask what this is good for.<BR />The productive webserver has its fixed IP address that travels together with the package <BR />(the same as ServiceGuard's relocative IP).<BR />This additional webserver is only required for maintenance of the cluster nodes.<BR />E.g. I mirrored a MiniCPAN (abt. 400MB) which I want to have serviced by the virtual host<BR />in case should immediate installation of additional CPAN modules be required on the cluster nodes.<BR /> <BR />Ok, here's the m4 mess I have started with,<BR />but somehow I think I haven't apprehended the notion of m4 yet.<BR />I thought it should be possible to simply assign a "macro", very much like a variable in any scripting language, only to be referrenced later.<BR />But this doesn't work in my definition of get_ip.<BR />You see, I don't want to repeat the long parsing command to retreive the IP address everywhere in situ where it is required.<BR /> <BR />When I have run this through m4<BR /> <BR /> <BR /> <BR /># cat vhosts.conf.mc <BR />define(`get_ip' , /sbin/ifconfig eth0|awk -F: '$1~/inet addr/{print$2}'|tr -cd '[0-9.]')<BR /><VIRTUALHOST syscmd=""><BR /> ServerName syscmd(/sbin/ifconfig eth0|awk -F: '$1~/inet addr/{print$2}'|tr -cd '[0-9.]'):ifdef(`PO<BR />RT', `PORT', 80)<BR /> ServerAdmin root@syscmd(/sbin/ifconfig eth0|awk -F: '$1~/inet addr/{print$2}'|tr -cd '[0-9.]')<BR /></VIRTUALHOST><BR /> <BR /> <BR />then this is what I get<BR /> <BR /> <BR /># m4 -DPORT=443 vhosts.conf.mc <BR /> <BR /><VIRTUALHOST></VIRTUALHOST>:443&gt;<BR /> ServerName 192.168.2.2:443<BR /> ServerAdmin root@192.168.2.2<BR /><BR /> <BR /> <BR />So how do m4 definitions are applied correctly?<BR /> <BR />Regards<BR />Ralph<BR /> Mon, 27 Feb 2006 12:44:37 GMT https://community.hpe.com/t5/operating-system-linux/macro-definitions-in-m4/m-p/3740220#M101279 Ralph Grothe 2006-02-27T12:44:37Z