Parser for NCSA httpd 1.0a5

You can find utility routines developed in NCSA together with example here. We want to present different package. Let us consider following (ruther silly) form example. It has just three variables defined :

Tell me your first name : <input name="fname" size=12>
Tell me your birthdate (year) : <input name="birthdate" 
    size=4 maxlength=4>
You encouter yourself <select name="age">
    <option> very young
    <option selected> young
    <option> mid age
    <option> old
</select>

It would be great if we could read form variables into C program variables. Let us define following variables :

char 
    *fname = NULL,      /* Variable for first name */
    *age;               /* Variable for age string */
int 
    birthdate = 0;      /* Variable for birthdate */

Now we have to build a table of partab_t elements (for details see header file parser.h), to give parser form variables names and pointers to C program variables :

partab_t table[]=
{   {&fname,    "fname",    PARSER_STRING},
    {&birthdate,"birthdate",PARSER_INT},
    {&age,      "age",      PARSER_STRING},
    {NULL,      NULL,       0}
};

• pointer to variable (e.g. &fname),
• name of form variable (e.g. "fname", which is name of the form variable defined through name="fname" in HTML source),
• variable type (using defines from parser.h header file).

The last thing to do is to run parser function defined in parser.c source file. Our program ( example.c) uses following code :

nread = parser(table, argc, argv);
if(nread < 0)
{   printf("parser internal error !");
    return(1);
}
else if(nread < sizeof(table)/sizeof(partab_t) - 1)
{   printf("ERROR: Parser read %d variable(s)", nread);
    return(1);
}

If parser is sucessful you can easily use variables read from the form. You can make calculations with int, long and float variables or deal with separately mallocked strings (char *).

Now look for the working version of form and C program or look at the sources :

parser

parser.h

parser.c

form exmaple

example.html

example.c

If you have any suggestions or comments press this. You can compare mailing program based on parser ( mailwww) to program written with procedures from util.c ( mailn).