Re: [qmailadmin] Stupid C questions
On Jan 8, 2004, at 6:56 PM, Rick Widmer wrote:
1. Does switch/case work with strings?
No. Only with byte/int/long/word datatypes.
It might be possible to build some sort of table of the commands and
the functions to call:
typedef struct {
char*command,
void (*function)(),
} functableentry;
const functableentry functable[] = {
{ showusers, show_users },
{ showaliases, show_aliases }
}
notfound = 1;
for (i = 0; notfound i (sizeof(functable) / sizeof(functable[0]));
i++) {
if (strcmp (functable[i].command, command) == 0) {
notfound = 0;
functable[i].function();
}
}
if (notfound) {
printf (invalid command: %s\n, command);
}
Note that with this system, you need to come up with a standard
function call (identical parameters and return value) to use for each
function in the table. Something like this could really clean up
command.c.
2. How much trouble is it to add or remove .c source files? Say all
the code in alias.c is obsolete except for a function or two and I
want to move those functions to a different file and remove it.
Not much trouble at all. We can just add or remove it from CVS and
Makefile.am.
--
Tom Collins - [EMAIL PROTECTED]
QmailAdmin: http://qmailadmin.sf.net/ Vpopmail: http://vpopmail.sf.net/
Info on the Sniffter hand-held Network Tester: http://sniffter.com/
Re: [qmailadmin] Stupid C questions
Yesterday I worked on template.c removing unused tags and moving large
blocks of code to separate functions, some to different files. There
are now 26 options with the form:
case '?' :
single line of code;
break;
4 like this, which I don't see any reason to mess with:
case '?' :
if(MaxSomething -1) {
printf( number / number );
} else {
printf( number / unlimited );
}
break;
and 9 others that are still farily long chunks of code that are very
likely to become functions today. I really like the way it looks with
all the single line actions in the switch.
I ran into some TmpBuf* variables which were declared in qmailadmin.c
and qmailadminx.h then used locally all over the program. I was worried
about interaction, so I went through each function in which they
appeared, and if they were initialized within the function I renamed
them from TmpBuf* to Buffer*, and declared them locally. It turns out
there were no interactions, now there is no question - they aren't
shared globals any more.
Tom Collins wrote:
On Jan 8, 2004, at 6:56 PM, Rick Widmer wrote:
1. Does switch/case work with strings?
No. Only with byte/int/long/word datatypes.
If we want to move from
/cgi-bin/qmailadmin/com/commandname?...
to
/qmailadmin/program.cgi?command=commandname
why not just go with single character commands that we can switch() on?
/qmailadmin/program.cgi?command=c
However, if I was doing this with PHP, a URL might look like:
http://server.x.com/qmailadmin/maildomain.com/name/edit.php
qmailadmin is a PHP program without the .php extension. I use the
following settings in httpd.com to make it execute:
Location /qmailadmin
ForceType applocation/x-httpd-php
/Location
/maildomain.com/username/edit.php would be available in PATH_INFO and
used to control operation of the program. This example would be editing
[EMAIL PROTECTED] The .php at the end is just there for show, I
never actually check the 'file extension'.
That works for PHP. It looks like ScriptAlias will allow something
similar for a c program. Are there any objections doing something like
this? Is there anyone who would have a hard time controlling the Apache
configuration on the mail server? Some web sites can not use the
ForceType trick because they can't change their Apache configuration,
but I'd be suprised if that was a problem on mail servers. Now is the
time to find out if this will be a big problem for someone...
Rick
Re: [qmailadmin] Stupid C questions
On Jan 9, 2004, at 4:33 PM, Rick Widmer wrote: Yesterday I worked on template.c removing unused tags and moving large blocks of code to separate functions, some to different files. There are now 26 options with the form: case '?' : single line of code; break; Note, that you could even do this: case '?': some_function_here(); break; You might want to put the break on a separate line, so you can be sure to see it. Missing breaks cause big problems. I ran into some TmpBuf* variables which were declared in qmailadmin.c and qmailadminx.h then used locally all over the program. I was worried about interaction, so I went through each function in which they appeared, and if they were initialized within the function I renamed them from TmpBuf* to Buffer*, and declared them locally. It turns out there were no interactions, now there is no question - they aren't shared globals any more. That's a good idea. Both qmailadmin and vpopmail use shared globals and it's just not a good idea. Upgrading some of the functions to pass values instead of relying on the global variables (like NewU) would be a good idea. If we want to move from /cgi-bin/qmailadmin/com/commandname?... to /qmailadmin/program.cgi?command=commandname why not just go with single character commands that we can switch() on? /qmailadmin/program.cgi?command=c I'd prefer to stick with cmd=commandname for readability. However, if I was doing this with PHP, a URL might look like: http://server.x.com/qmailadmin/maildomain.com/name/edit.php qmailadmin is a PHP program without the .php extension. I use the following settings in httpd.com to make it execute: Location /qmailadmin ForceType applocation/x-httpd-php /Location Not everyone uses Apache -- QmailAdmin works with other web servers. Keeping all parameters as values in the URL means that you can also move them to hidden fields in a POST. There's flexibility in being able to pass values in the URL (GET style) and/or form data (POST style). You could even store some values in a cookie (like the username and domain name) to make the URLs smaller. If the user isn't accepting cookies, just include them in the URL (from template.c). -- Tom Collins - [EMAIL PROTECTED] QmailAdmin: http://qmailadmin.sf.net/ Vpopmail: http://vpopmail.sf.net/ Info on the Sniffter hand-held Network Tester: http://sniffter.com/
[qmailadmin] Stupid C questions
I know these are very basic language questions, but since I am working
on QmailAdmin, please humor me...
1. Does switch/case work with strings?
switch( command ) {
case showusers :
show_users();
break;
case showaliases :
show_aliases();
break;
}
2. How much trouble is it to add or remove .c source files? Say all
the code in alias.c is obsolete except for a function or two and I want
to move those functions to a different file and remove it.
Right now I am searching for code that is never called and removing it.
Rick
