Parsing string based on initial format
- by Kayla
I'm trying to parse a set of lines and extract certain parts of the string based on an initial format (reading a configuration file).
A little more explanation: the format can contain up to 4 parts to be formatted. This case, %S will skip the part, %a-%c will extract the part and will be treated as a string, %d as int.
What I am trying to do now is to come up with some clever way to parse it. So far I came up with the following prototype. However, my pointer arithmetic still needs some work to skip/extract the parts.
Ultimately each part will be stored on an array of structs. Such as:
struct st_temp
{
char *parta;
char *partb;
char *partc;
char *partd;
};
...
#include <stdio.h>
#include <string.h>
#define DIM(x) (sizeof(x)/sizeof(*(x)))
void process (const char *fmt, const char *line) {
char c;
const char *src = fmt;
while ((c = *src++) != '\0')
{
if (c == 'S'); // skip part
else if (c == 'a'); // extract %a
else if (c == 'b'); // extract %b
else if (c == 'c'); // extract %c
else if (c == 'd'); // extract %d (int)
else {
printf("Unknown format\n");
exit(1);
}
}
}
static const char *input[] = {
"bar 200.1 / / (zaz) - \"bon 10\"",
"foo 100.1 / / (baz) - \"apt 20\"",
};
int main (void) {
const char *fmt = "%S %a / / (%b) - \"%c %d\"";
size_t i;
for(i = 0; i < DIM (input); i++)
{
process (fmt, input[i]);
}
return (0);
}
