I have been trying to look for the answer to this question...but I haven't found it.
I have to parse an string in C in the way
Send XMb to eth0 eth1 wlan0 with rates 1 2 3
Send YMb to em1 wlan0 with rates 2 5
The thing is that I don't know the amount of elements I'll have in the list..therefore I don't know how many %s to put.
Thanks in advance.
One possible solution is to read in the whole command and process it later. For example, you can tokenize your command string with delimiter ' ' (a whitespace). Then you look for all tokens between "to" and "with", which will be your destination of sending. Similarly, you can find the rates by looking for tokens after "rates".
Another possibility is to parse the string with sscanf (or fscanf) and make use of the %n specifier, which stores the number of characters processed up to that point.
#include <stdio.h>
#include <string.h>
int main() {
char str[] = "Send XMb to eth0 eth1 wlan0 with rates 1 2 3";
char val[100];
char c[2];
int n = 0, m;
if (sscanf(str, "Send %1[XY]Mb to %n", c, &n) == 1) {
printf("%s\n", c);
while (sscanf(str+n, "%99s%n", val, &m) == 1) {
n += m;
if (strcmp(val, "with") == 0)
break;
printf("%s\n", val);
}
sscanf(str+n, " rates%n", &m);
n += m;
while (sscanf(str+n, "%99s%n", val, &m) == 1) {
printf("%s\n", val);
n += m;
}
}
return 0;
}
